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Inorganic Electronic Spectroscopy
... The transition, 4 A 2 ! 4 T 1 (P), exhibits a splitting in the spectra, which may be attributed to the lowering of the symmetry due to the distortions at the tetrahedral positions from T d to C 3v and C 2v . [50][51][52] The T 1 state of the tetrahedra can be split in to A 2 + E and A 2 + B 1 + B 2 , on the change of symmetry to C 3v and C 2v , respectively. The splitting can affect the separation of each of the multiplets in the visible spectra, which could result in the broadening of the spectra ( Figure 5). ...
... Similar to the Co 2 + ions in tetrahedral geometry, the transitions ν 1 and ν 2 are observed in the near infrared region whereas ν 3 is observed in the visible region. [50] The transition, 3 T 1 (F)! 3 T 1 (P), is expected to exhibit multiplets when the T d symmetry is unperturbed. The splitting of the transition becomes broader when the tetrahedral site is distorted. ...
... It is known that the Ni 2 + ions generally have limited stability in tetrahedral coordination. [50] The optical absorption spectra for the nickel containing materials have strong absorption at~1.8 and 2.2 eV ( Figure 6). These absorptions leave a valley with no absorption and correspond to the red and green region. ...
A new compound, InBaZn3GaO7, with swedenborgite structure along with transition metal (TM) substituted variants have also been prepared. The structure contains layers of tetrahedral ions (Zn²⁺/Ga³⁺) connected by octahedrally coordinated In³⁺ ion forming the three‐dimensional structure with voids where the Ba²⁺ ions occupy. The TM substituted compounds form with new colors. The origin of the color was understood based on the ligand‐field transitions. The near IR reflectivity studies indicate that the Ni – substituted compounds exhibit good near – IR reflectivity behavior, making them possible candidates for ‘cool pigments’. The temperature dependent dielectric studies indicate that the InBaZn3GaO7 compound undergoes a phase transition at ~360 °C. The compounds are active towards second harmonic generation (SHG). Magnetic studies show the compounds, InBaZn2CoFeO7 and InBaZn2CuFeO7 to be anti‐ferromagnetic in nature. The copper containing compounds were found to be good catalysts, under visible light, for the oxidation of aromatic alkenes. The many properties observed in the swedenborgite structure‐based compounds suggests that the mineral structure offers a fertile ground to investigate newer compounds and properties.
... On comparison with ligand spectrum, the Cu(II) complex's spectrum, in DMSO, displayed two bands at 46,510 and 29,850 cm −1 with a shoulder at 25,316 cm −1 were assigned to the intra-ligand transitions (π→π*) Ar , (π→π*) C=X and (n→π*) C=X , respectively (Fig. 4B). Furthermore, the two new bands at 23,256 and 15,270 cm −1 were attributed to the ligand to metal charge transfer (LMCT) transition and 2 T→ 2 E transition of tetrahedral geometry [51,52] (Table 3). In addition, the complex exhibited magnetic moment 2.17 B.M. that is in the normal range of Cu(II) complexes regardless of their stereochemistry [52], 1.75-2.20 ...
... In DMSO, the spectrum of the Co(II) complex was carried out and showed two bands at 16,395 and 14,525 cm −1 attributed to 4 T 1g (F)→ 4 T 1g (P) (υ 3 ) and 4 T 1g (F)→ 4 A 2g (P) (υ 2 ) transitions, respectively, suggesting an octahedral geometry around the metal ion [51]. The band at 19,415 cm −1 was assigned to the ligand to metal charge transfer (LMCT) while the two bands observed at 25,315 and 22,990 cm −1 were corresponding to the n→π* transition of the azomethine groups (Additional file 1: Fig. S3). ...
... The band at 19,415 cm −1 was assigned to the ligand to metal charge transfer (LMCT) while the two bands observed at 25,315 and 22,990 cm −1 were corresponding to the n→π* transition of the azomethine groups (Additional file 1: Fig. S3). The spectral data were utilized to estimate the ligand field parameters, υ 1 , B and 10Dq, using the spin allowed transitions of the d 7 -system and were found to be 6790, 703, and 7730 cm −1 , respectively, which were in the octahedral structure range [25,51]. The magnetic moment of the Co(II) complex was found to be 5.16 B.M., in accordance with the usual values of octahedral geometry, 4.3-5.2 ...
The ligand, N′ -(furan-2-ylmethylene)-2-hydroxybenzohydrazide (H 2 L), was synthesized characterized through various spectral studies which cleared out that the free ligand existed in keto form. The ligand upon reaction with Cu(II), Co(II), Ni(II) and Zn(II) acetates yielded complexes with stoichiometric ratio 1:2 (M:L) which has been validated through the elemental and mass spectral measurements. The IR and NMR spectral studies of the isolated complexes disclosed that the ligand chelated to metal ion in mononegative bidentate fashion via the azomethine nitrogen and deprotonated enolized carbonyl oxygen. Moreover, the DFT quantum chemical calculations designated that the ligand and Ni(II) complex exhibited the highest and lowest values of HOMO, LUMO energies and HOMO-LUMO energy gap, respectively. Furthermore, the in vitro cytotoxic activity towards HePG-2 and HCT-116 cell lines of the isolated compounds was investigated and the data cleared out that the ligand was more potent than the metal complexes.
... -1 ) due to (π→π * ) electronic transition while the second peak at (369nm, ῡ = 10752 cm -1 , ɛ max = 930 L.mol -1 .cm -1 ) due to (n→π * ) electronic transition (11). And finally the micro analysis of the elements Cal. ...
... -1 ) due to (π→π * ) electronic transition while the second peak at (382nm, ῡ = 26178 cm -1 , ɛ max = 1100 L.mol -1 .cm -1 ) due to (n→π * ) electronic transition (11). And finally the micro analysis of the elements Cal. ( ...
... -1 ) due to (π→π * ) electronic transition while the second peak at (360nm, ῡ = 27777 cm -1 , ɛ max = 867 L.mol -1 .cm -1 ) due to (n→π * ) electronic transition (11). The predicated H 1 NMR of the free Ligand ( The suggested molecular formula has been also supported by the spectral measurements, molar conductivity, elemental analysis and magnetic susceptibility. ...
Iron(III), Cobalt(II), Cupper(II), Zinc(II) and Mercury(II) complexes have been synthesized by reaction of their chloride salt with a new tetradentate Schiff base ligand type N4: (N1Z,N2Z)-N1-(4-((Z)-4-(dimethylamino)benzylideneamino)-2,3-dimethyl-1-phenyl 1,2dihydropyrazol-5-ylidene)-N2(4((Z)-furan-2-ylmethyleneamino)-2,3-dimethyl-1-phenyl-1,2dihydropyrazol-5-ylidene)ethane1,2–diamine. All the prepared complexes were characterized by the spectroscopic methods (FT.IR, UV-Vis) Atomic Absorption, Magnetic Susceptibility, Melting Point, Elemental Analysis and Molar Conductivity, as well as the H1NMR for the free ligand. According to the resulted data from the above mentioned techniques, the octahedral structure geometry was proposed for Fe(III) complex with the formula [FeLCl2]Cl, and tetrahedral geometry was proposed for the rest with a general formula [ML]Cl2.
... The UV-VIS absorption spectrum displayed three bands at 486, 686 and 1000 nm with Ɛ ≤ 50 M -1 cm -1 , which is consistent with a high coordination number. [43][44] The characterization was completed with the IR spectrum, confirming the presence of ClO4counter anions (δ = 620 cm -1 ), and HRMS (see the SI). The three Co II Calix-TMPA X complexes were synthesized in good yields (> 80%) in MeCN by reacting ligands Calix-TMPA X with cobalt(II) perchlorate hexahydrate ( Figure 3). ...
... 50-80 M -1 cm -1 (Figure 6). These absorptions are typical for 5-coordinate Co II complexes [43][44] and are clearly different from those exhibited by the 7-coordinate complex Co II TMPA CH2OH . IR spectra of the three complexes further confirmed the dicationic state of the cobalt ion, with two perchlorates as counterions (see the SI). ...
The synthesis of a series of mononuclear, dicationic CoII funnel complexes is reported herein. Three ligands Calix‐TMPAX present a calix[6]arene cone closed at its small rim by a tris(2‐pyridylmethyl)amine (TMPA) unit and differ by the nature of three cavity walls, anisole, phenol or quinone. The X‐ray diffraction structure of [CoII(MeCN)Calix‐TMPAOMe](ClO4)2 displays a trigonal bipyramidal geometry, with Co bound to all 4 nitrogen atoms of the TMPA cap, and to one MeCN guest molecule buried inside the calixarene cavity. All complexes were fully characterized in solution as high spin 5‐coordinate species using various techniques, including 1H NMR spectroscopy. For comparison purpose, an analogous CoII complex based on the TMPACH2OH ligand, devoid of a calixarene core, was synthetized. Its X‐ray structure shows a dicationic 7‐coordinate cobalt(II) center in the N4O3 environment provided by the ligand, leaving no space for exogenous ligand binding. This contrasts with the 5‐coordinate complexes obtained with the calix‐ligands that allow guest‐ligand binding and exchange. A brief overview of the coordination properties of the calix‐complexes, compared to those obtained with TMPA ligands, devoid of a cavity, highlights major differences in terms of complexation kinetics, geometry, coordination to the labile site, anion affinity, nuclearity, and stability.
... A high spin octahedral configuration has been indicated by the magnetic moment values of manganese(II) compounds observed at 5.34 and 5.45 B.M. [22]. Three unpaired electrons in the Co(II) ion are indicated by the magnetic measurements (4.53, 4.63 B.M.) for Co(II) compounds, which is suitable for their octahedral geometry [23,24]. The magnetic moment values of nickel(II) compounds (2.98, 2.99 B.M.) are in agreement with the magnetic susceptibility value (2.9-3.3 ...
... The related methyl protons in the (OCH3) group can be seen as a single peak at 3.72, 3.61 ppm integrated for three protons. At 2.5 ppm, the DMSO signal appeared [23] (Figure 3a). The spectrum of the complex Zn(II) (Figure 3b) displayed multiple signals. ...
Complexes of mixed-ligand Schiff bases [trimetho-prim (TMP) with isatin] (L1) and nitrogen bases [2,2′-bipyridine (bipy)] (L2), [1,10-phenanthroline (phen) (L3)] with metal chlorides: M = Cr3+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+ were prepared and characterized by metal content determination (%), FT-IR, electronic, nuclear magnetic resonance, mass spectroscopy, magnetic susceptibility, conductance measurements and elemental analysis (CHN). The bacterial activity of the ligands and their metal compounds was evaluated via various microorganisms. Infrared spectra of Schiff base showed an azomethine peak shifted in complexes that coincide synthesis and coordination of Schiff base through the nitrogen atom of azomethine C=N) and the oxygen atom of the carbonyl group of L1 with metal ions. L2, L3 (bipy, phen) coordinated through the di imine nitrogen atoms. Conductance dimensions suggested the non-conductance nature of all the compounds except Cr(III) complexes, this outcome fits in with the molar conductance value estimated for 1:1 electrolyte in DMF. Magnetic susceptibility analysis and electronic spectra indicated an octahedral geometry for all complexes. Biological study for prepared compounds have been evaluated towards pathogenic microbes Staphylococcus aureus and Bacillus subtilis. Some compounds have stronger antibacterial action than Schiff base towards tested microbes. KEY WORDS: Antimicrobial, Heterocyclic compounds, Schiff base, Trimethoprim drug, 2,2-Bipyridyl, 1,10-Phenanthroline Bull. Chem. Soc. Ethiop. 2024, 38(4), 1013-1025. DOI: https://dx.doi.org/10.4314/bcse.v38i4.16
... The d-d area at 755 nm in the [Co(L)Cl].H2O disclosed band is caused by 4T1(F)→4A2(F), which indicates a four-coordinated complex with a tetrahedral shape surrounding the Co(II) center. The magnetic moment value µ eff = 4.28BM for the complex is consistent with the tetrahedral configuration around the Co atom [29,30]. An octahedral structure surrounding the metal center was revealed by a peak in the Ni(II)-complex at 890 nm, which was ascribed to 3A2g→3T1g(F). ...
... The octahedralshape agrees with the magnetic moment value µ eff =3.73 BM of the Ni(II)-complex. The [Cu(L)Cl(H 2 O) 2 ]spectrum revealed a peak at 741nm, which was attributed to 2 T 2 g→ 2 B 2 g, indicating a distorted octahedral arrangement about the metal centre [29,30]. The copper complex's µeff = 1.82 BM magnetic moment value is consistent with the distorted octahedral shape. ...
... The electronic spectra of the complex 1 have been recorded in methanol solution of the compound at room temperature and the data are summarized in the Experimental section. The electronic spectrum of the copper complex exhibits bands at 422 nm and 550 nm which can be assigned to 2 B 1g 2 A 1g and 2 B 1g 2 E 1g transitions 22,23 . The complex also shows two intense bands in the near ultraviolet region due to * and ligand ( L ) metal (e g ) charge transfer transition 24 . ...
The tri-dentate ONO-donor Schiff base ligand H 2 L was produced from the condensation of benzoylacetone and 3-aminopropanol. This tri-dentate alcohol based ligand was treated with Cu(ClO 4) 2 .6H 2 O to generate two doubly alkoxo bridged di-nuclear copper(II) complex [Cu 2 L 2 ] 1. Characterization of this compound was carried out by various spectroscopic tools. Compound 1 crystallizes in orthorhombic space group P2(1)/n with a = 7.322 Å, b = 9.938 Å, c = 16.137 Å. Single crystal X-ray diffraction study reveals that in di-nuclear copper compound [Cu 2 L 2 ] 1, both the metal centers adopt a square planar environment and two Cu II centers are bridged by two alkoxo groups. The electronic spectrum of the copper complex shows bands at 422 nm and 550 nm which can be assigned to 2 B 1g 2 A 1g and 2 B 1g 2 E 1g transitions. The compound shows antibacterial activity. Antibacterial activity of complex 1 was performed by well plate technique. In the above experiment, V. hydrophila, S. aureus and B. cereuscoli were found sensitive to di-nuclear copper(II) complex [Cu 2 L 2 ] 1.
... The nujol mull electronic spectrum of the copper(II) complex showed a broad d-d band in the 540 nm region (18,518 cm −1 ) which can be assigned to 2T2g → 2Eg transition of an octahedral geometry [33]. Though under the influence of the tetragonal distortion, the 2Eg and 2T2g states of the octahedral Cu(II) ion (d9) split, and three transitions 2B1g→2Eg, 2B1g →2B2g, and 2B1g → 2A1g are expected [78][79][80], but their very close energies makes them appear in the form of one broad band. ...
Newly synthesized ligand 2-(2- acetamidophenyl)-2-oxo-N-(pyridin-2-ylmethyl)acetamide and its copper(II) complex were characterized by elemental analyses, FT-IR, UV–Vis., ESR, ¹H-NMR, and thermal analysis along with the theoretical quantum chemical studies. Combined experimental and theoretical DFT (density functional theory) studies showed the ligand to be a tridentate ligand with three coordinate bonds. The complex was suggested to be in a distorted octahedral structure with dx²-y² ground state. The activation energy, ΔE*; entropy ΔS*; enthalpy ΔH* and order of reaction has been derived from differential thermogravimetric (DTA) curve, using Horowitz–Metzeger method. The nujol mull electronic spectrum of the ligand and Cu(II) complex have been recorded and the difference of the excited and ground state densities has also been theoretically calculated and plotted to investigate the movement of electrons on excitation. The Cu(II) complex was evaluated for its antibacterial activity against two bacterial species, namely Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Antifungal screening was performed against two species (Condida albicans and Aspergillus flavus). The complex under investigation was found to possess notable biological activity. Molecular docking investigation predicted different types of non-covalent interactions of the synthesized ligand towards Insulin-like growth factor 1 receptor (ID: 5FXR).
... Complex 2 showed a broad band at 735 nm, characteristic of a distorted octahedral geometry, and a shoulder at 380 nm, which was attributed to charge transfer transitions, while the spectrum of complex 3 exhibited a CT shoulder at 395 nm and a d-d band centered at 700 nm, consistent with a five-coordinate structure [48]. In the spectrum of complex 4, a broad d-d transition band centered at 640 nm was identified, in agreement with the octahedral geometry of the local environment, and a type NiN 3 O 3 chromophore [49], while the band exhibited at 330 nm was assigned to charge transfer transitions. ...
Four complexes of essential metal ions, Cu(II) and Ni(II), with the new sulfonamide ligand N-(pyridin-2-ylmethyl)quinoline-8-sulfonamide (HQSMP) were synthesized and physicochemically and structurally characterized. Complex [Cu(QSMP)Cl]n (2) consists of a polymeric chain formed by distorted square pyramidal units. In 2, the sulfonamide ligand acts as a bridge coordinating to one Cu(II) through its three N atoms and to another metal ion via one O atom in the sulfonamido group, while the pentacoordinate complex [Cu(QSMP)(C6H5COO)] (3) presents a highly distorted square pyramidal geometry. Complex [Ni(QSMP)(C6H5COO)(CH3OH)][Ni(QSMP)(CH3COO)(CH3OH)] (4) consists of two mononuclear entities containing different anion coligands, either a benzoate or an acetate group. Both units exhibit a distorted octahedral geometry. The interaction of the complexes with CT-DNA was studied by means of UV-Vis and fluorescence spectroscopy, interestingly revealing that the Ni(II) complex presents the highest affinity towards the nucleic acid. Complexes 1 and 2 are able to cleave DNA. Both compounds show promising nuclease activity at relatively low concentrations by mediating the production of a reactive oxygen species (ROS). The interaction of the four complexes with bovine serum albumin (BSA) was also investigated, showing that the compounds can bind to serum proteins. The antitumor potential of complexes 1 and 2 was evaluated against the A549 lung adenocarcinoma cell line, revealing cytotoxic properties that were both dose- and time-dependent.
... It also falls in the region of low spin and the square planar Co(II) geometry involving transitions from xz, yz→z 2 and x 2 -y 2 →z 2 . This can conclude that complex 2 exhibits distorted octahedral stereochemistry around Co(II) [32,33]. The band at 413 nm is not distinct at lower concentration but appears as distinct band at higher concentration. ...
Four new transition metal complexes (1-4) were successfully synthesized through the reaction of M(NO3)2·nH2O (M = Ni, Co, Cd or Zn;
n = 6 for Ni, Co, Zn; n = 4 for Cd) with 1,1-dicyanoethylene-2,2-dithiolate (i-MNT2–) and p-phenylenediamine (PPD) ligands. The
syntheszed metal complexes were characterized by CHN-analysis, electronic, FTIR and 1H NMR spectroscopic techniques. The electronic
transition investigations reveals six coordinate octahedral geometry for Ni(II), distorted octahedral for Co(II), four coordinate tetrahedral
geometry for Cd(II) and Zn(II) complexes. All the four metal complexes displayed a significant red shift in the absorption maximum,
suggesting their successful assembly. The luminescence behaviour exhibited the prominent fluorescence within the visible range. The
current-voltage characteristics revealed that complexes 2 and 3 exhibited ohmic behaviour, displaying a linear curve. On the other hand,
complexes 1 and 4 initially maintained a low conducting state (OFF state) until a specific voltage threshold (VTh), beyond which the
current sharply increased, transitioning to a higher current state (ON state). The FESEM images of the metal complexes strongly indicated
a nano-scale aggregated structure. In terms of antibacterial activity, complexes 3 and 4 demonstrated promising efficacy against various
bacterial strains, with complex 3 being particularly potent. The fungicidal activity of all four metal complexes was remarkable against
Magnaporthe grisea, Cochliobolus miyabeanus and Synchitrium endobioticum, however, no fungicidal activity was found against Trichophyton
mentagrophytes and Candida albicans.
... The Austrian Journal of Technical and Natural Sciences, No 3 -4 Section 1. Chemistry 1971; Grand' A. F. and Tamres', M. 1969;Lever, A. B. P. 1987). ...
... The spectra of the mix [Cu(C 15 H 14 N 2 OS)(C 2 H 5 NO 2 ]Cl 2 complex shows bands in (27.750 and 24096)cm -1 these bands corresponded to 2 B 1 g 2 Eg and 2 B 1 g 2 A 1 g , the location of these bands together with magnetic moment value (1.86 BM) gave "the square planer geometry around copper [14][15][16] -132 - ...
تم تصنيع يجند جديد وتمييزه بواسطة التحليل الطيفي (FTIR) و Uv-vis و C.H.N. انتواع مجمعات يجند مختلطة من Co (II) و Ni (II) و Cu (II) مع 3- أمينو -2 ميثيل -2-فينيل-2H-benzol [e] [1،3] ثيازين- (3H) - تم تحضير واحد وجليسين وعزلهما وتمييزهما بـ (FTIR) وأطياف الأشعة فوق البنفسجية وقياسات الامتصاص الذري والموصلية وقياسات الحساسية المغناطيسية. تمت دراسة الفعالية البيولوجية للمركبات المحضرة ضد أنواع مختارة من البكتريا والفطريات ، للبكتيريا سلبية الغرام مثل الإي كولاي و الجرام الموجبة مثل المكورات العنقودية الذهبية. كانت الهياكل الجزيئية للمجمعات المحضرة المقترحة وفقًا لنتيجة أطياف الأشعة تحت الحمراء والأشعة فوق البنفسجية والقابلية المغناطيسية والتوصيل المولي ، عبارة عن ثماني السطوح لـ Co (II) و Ni (II) بينما هندسة مخطط مربع لمجمع Cu (II)
... The band with the maximum at 970 nm gives the value of the 10Dq parameter: 10310 cm -1 . The weak and sharp band at 767 nm is due to the spin forbidden transition, 3 A2 → 1 E. [18][19][20] The band located at 214 nm is probably due to one of the anions or to a metal-toligand charge transfer. ...
... The C=O, C=C, and C=N chromophoric groups induce π-π* transitions and contribute to the cef sodium salt-free ligand's maximum wavelength at 290 nm. The variance in wavelength data among complexes I-III may arise not from the intrinsic properties of the ligand but rather from the interaction of metal ions with the ligand, resulting in metal complex formation [31]. The complexes spectral bands underwent a bathochromic shift to higher values, and the emergence of new absorption bands suggested complex formation [32]. ...
Three new metal complexes of ceftriaxone (cef), incorporating platinum(IV), gold(III), and ruthenium(III), were prepared. The complexes were prepared using a 1:2 molar ratio between ceftriaxone sodium salt (Na2cef) to AuCl3, PtCl4, and RuCl3 salts in methanol solvent. The as-synthesized complexes were characterized using microanalytical techniques for C, H, N, and S elements, magnetic and molar conductance measurements, as well as spectroscopic methods including FTIR, 1H NMR, and UV-Vis. The shape, morphology and size calculations have been examined using SEM, TEM, and X-ray diffraction data. The cef complexes were six-coordinate systems possessing a distorted octahedral geometry. Through the oxygen of both triazine and carboxylate moieties with the chemical formulae [Au(cef)2(Cl)(H2O)] (I), [Pt(cef)2(Cl)2] (II), and [Ru(cef)2(Cl)(H2O)] (III) the antibiotic cef acts as a bidentate ligand towards three metal ions. The newly created complexes demonstrated antibacterial activity showing efficacy in comparison to the cef sodium ligands. In vitro, antibacterial assays against specific microorganisms were evaluated to assess the antibacterial activities of the complexes. Cytotoxicity assays for cef complexes were conducted for HepG-2 and MCF-7 cell lines, representing human hepatocellular carcinoma and breast cancer, respectively. A value of 22.4 g and 26.2 g for 50% inhibitory concentration (IC50), respectively, for HepG-2 and MCF-7 were obtained for [Ru(cef)2(Cl)(H2O)] (III). KEY WORDS: Ceftriaxone sodium, Gold, Ruthenium, Platinum, Complexes, FTIR, IC50 Bull. Chem. Soc. Ethiop. 2024, 38(4), 937-948. DOI: https://dx.doi.org/10.4314/bcse.v38i4.10
... The spectrum of the [Cu(CIPH)(CIP)(H 2 O) 2 ](NO 3 )(H 2 O)(C 2 H 5 OH) complex (Fig. 3d) exhibits a broad band centered at 878 nm, which is assigned as the 2 T 2g ← 2 E g transition and the value of μ eff is 1.93 B.M, which proves that the complex structure is octahedral (Fig. 4) [49,50]. ...
Ciprofloxacin (CIPH) was classified as one of the most effective quinolone antibiotics, which is commonly used to cure a wide range of infections resulting from Gram-negative and Gram-positive microorganisms. The complexes which formed due to the interaction of Ni(II), Zn(II), Cu(II), Gd(III) and Sm(III) with ciprofloxacin were characterized by CHN% analysis, conductivity, FTIR, electronic spectra, fluorescence measurements, and magnetic susceptibility, besides studying the complex–DNA interaction. Meanwhile, the molar conductance values (0.001 mol·L⁻¹ in DMSO) revealed the electrolytic behavior of the complexes and could be designated with the A⁻B⁺ formula. In addition, the geometry of the compounds was confirmed from the electronic transitions as well as the μeff values as octahedral for all complexes. The postulated formula could be generally assigned as [M(CIP)a(CIPH)b(H2O)c](NO3)(H2O)n(C2H5OH)m. Moreover, the interaction between metal complexes and DNA revealed that the Cu complex had the highest binding constant. Nanotechnology was applied to synthesized compounds using silica nanoparticles (SiNPs), which were prepared using a sol–gel process. The silica nanoparticles were chemically functionalized for binding the ligand and its metal complexes; this enables the as-prepared compounds to enhance their features as a drug delivery platform. Meanwhile, the antimicrobial activity was tested for the free complexes and SiNPs composites. Collectively, Sm complex gave the largest zone of inhibition, while the Cu(II)–SiNPs composite showed the strongest potential to reduce the bacterial activity. Furthermore, the fluorescence data of CIPH, ligand–metal mixture and the effect of silica nanoparticles on them were studied.
... The UV-Vis spectrum of the ligands in Figure (8) showed four maximum absorption bands: the first absorption band appeared at (421.2 nm, 23741cm -1 ) was belonged to intra ligand charge transfer (ILCT), the second and the third high intensity peaks appeared in the UV region at (362.8 nm, 27563 cm -1 ) and (327.6 nm, 30525cm -1 ) were assigned to (n→π*) transitions, while the fourth absorption band appeared at (259.6 nm, 38520 cm -1 ) due to (π →π*) [18] . Electronic transitions with their assignments for ligand and all complexes are summarized in Table (3) [19,20]. ...
In this research, a new heterocyclic compound (E)-2-(4-((2-(2-((2-hydroxynaphthalen-1-yl) methylene) hydrazinyl) thiazol-4-yl) amino) phenyl) acetic acid was synthesized from the reaction of 2-hydroxynaphthalene-1-carbaldehyde with 2-(4-((2-hydrazinylthiazol-4-yl)amino)phenyl)acetic acid. This compound was utilized as the ligand (HL) to synthesize series of complexes by its reaction with some metals elements salts (cobalt chloride hexahydrate, nickel chloride hexahydrate, copper chloride dihydrate and anhydrous zinc chloride). The ligand was characterized using different types of analytical techniques such as FT-IR, 1H-NMR, mass spectrum and UV-Vis. Spectrum. The complexes were characterized by using UV-Vis- spectrum, LC.-MS. technique, FT-IR spectrophotometer, conductivity measurements, magnetic susceptibility and atomic absorption. The results of the analysis revealed that the final structures of the complexes are octahedral.
... 86,87 The CV of complex 2 also shows a two-step electron transfer The likely substitution of the Cl − and the pincer ligands with solvent molecules in the electrochemical process is further investigated by replacing DMF with MeCN. 73 MeCN significantly shifts the redox potentials in the electrochemical process, especially for the potentials associated with the substitution of the Cl − and pincer ligands ( Figure S7). ...
Chromium(III) complexes bearing bidentate {NH2(CH2)2PPh2: PN, (S,S)-[NH2(CHPh)2PPh2]: P’N} and tridentate [Ph2P(CH2)2N(H)(CH2)2PPh2: P-NH-P, (S,S)-(iPr)2PCH2CH2N(H)CH(Ph)CH(Ph)PPh2: P-NH-P′] ligands have been synthesized using a mechanochemical approach. The complexes {cis-[Cr(PN)Cl2]Cl (1), cis-[Cr(P’N)Cl2]Cl (2), mer-Cr(P-NH-P)Cl3 (3), and mer-Cr(P-NH-P′)Cl3 (4)} were obtained in high yield (95–97%) via the grinding of the respective ligands andthe solid Cr(III) ion precursor [CrCl3(THF)3] with the aid of a pestle and mortar, followed by recrystallization in acetonitrile. The isolated complexes are high spin. A single-crystal X-ray diffraction study of 2 revealed a cationic chromium complex with two P’N ligands in a cis configuration with P′ trans to P′ with chloride as the counteranion. The X-ray study of 4 shows a neutral Cr(III) complex with the P-NH-P′ ligand in a mer configuration. The difference in molecular structures and bulkiness of the ligands influence the electronic, magnetic, and electrochemical properties of the complexes as exhibited by the bathochromic shifts in the electronic absorption peaks of the complexes and the relative increase in the magnetic moment of 3 (4.19 μβ) and 4 (4.15 μβ) above the spin only value (3.88 μβ) for a d³ electronic configuration. Complexes 1–4 were found to be inactive in the hydrogenation of an aldimine [(E)-1-(4-fluorophenyl)-N-phenylmethanimine] under a variety of activating conditions. The addition of magnesium and trimethylsilyl chloride in THF did cause hydrogenation at room temperature, but this occurred even in the absence of the chromium complex. The hydrogen in the amine product came from the THF solvent in this novel reaction, as determined by deuterium incorporation into the product when deuterated THF was used.
... The spectra of the complexes showed shoulders at (405-572 nm), which are assigned to LMCT (ligand-to-metal charge transfer) from the ligands to the empty (d) orbital of vanadium(V). Vanadium(V) complexes with (d 0 ) electronic configuration don't have the (d-d) electronic transition which can be explained by the fact that vanadium(V) has an empty (d) orbital[25]. The experimental UV-Vis. ...
Two dioxidovanadium(V) complexes have been prepared with dinitrogen atoms donor (o-phenylenediamine (OPD) and dithiooxamide (DTO)) ligands. The cytotoxicity studies of the prepared complexes against the L20B cell line showed that they have moderated activity against the L20B cell line. The complexes were characterized by different spectral techniques such as FT-IR, UV-Vis., mass, ¹ H-NMR spectroscopy, magnetic susceptibility, molar conductivity, and finally the spectral data were compared with the data obtained by the DFT theoretical calculations. The obtained spectroscopic data confirmed that the two ligands are coordinated from the two amine groups and in cis-conformation with the two oxygen atoms. The experimental and theoretical calculations showed that the two complexes are mononuclear with proposed distorted octahedral structures. The complexes are very stable, the electronic energies are (-773.10 and − 907.56 a.u.), the HOMO orbitals energies are (-0.386 and − 0.504 a.u.), and the LUMO orbitals energies are (-0.213 and − 0.421 a.u.) for the complexes; respectively. The bond angles around the vanadium(V) atoms are in the range (69.44–91.36 A°), and the dihedral angles are in the range (111.22-161.94 °). Calculations explained the complexes are polarized (3.39–5.28) more than the free ligands (0.002-3.00). The electronic transition in the complex (2) (0.083) is less than for the complex (1) (0.173). The complexes showed good solubility in water. Finally, the best cytotoxic result is for the complex (1) against the L20B cell lines and this open the door to use this complex with oral administration in future studies.
... The measurements of the magnetic moment of the complexes in Table 2, were measured at 25 ºC. The magnetic moment for Cu (II) (1,2) is (2.26, 1.69 ) B.M. respectively suggests a tetrahedral and octahedral configuration [11,12]. ...
Two complexes-derived from dithiocarbamate ligand (L) and their adduct with nitrogen base of the general formula [Cu(L) 2 ], [Cu(L) 2 (A)] obtained by the condensation of CuCl 2 .2H 2 O with L= diisopropyl amine dithiocarbamate and A=1,10-phenanthroline weve directly been synthesized and characterized by infrared spectra, metal content and magnetic measurement. Some properties of these two complexes, including UV/VIS absorption, melting point, and molar conductivity measurement are characterized in both cases before and after applying laser diode radiation with an emission wavelength of 532 nm. It found that laser has potential effects on Cu complexes under investigation for specific conditions and doses where new complexes have been observed, and spectral data and magnetic measurement showed a tetrahedral and octahedral geometries for [Cu(L) 2 ] and[Cu(L) 2 (A)], respectively.
... The magnetic measurements showed the cobalt ion in its greenish blue complex to be paramagnetic with (d 7 )configuration in distorted tetrahedral environment (15),in infrared region the( 1 ) is found as a weak band at (3451)cm -1 due to transition 4 A 2 → 4 T 2 the ( 3 ) was calculated as the average to three bands and assigned to the transition 4 A 2 → 4 T 1 (p) at about (16977) cm -1 ,while the ( 2 ) was calculated by reference to T.S.D for d 7 configuration (16,17) to the transition 4 A 2 → 4 T 2 (f). The Racahparameter B -, nephelauxetic factor β and the value of (10 Dq) were also estimated as describe in table (3). ...
Coblatcomplex has been prepared by reaction between C16H19N3O3S (L) as ligand and metal salt (II). The prepared complex were characterized by infrared spectra, electromic spectra, magnetic susceptibility, molar conductivity measurement and metal analysis by atomic absorption and (C.H.N) analysis. From these studies tetrahedral geometry structure for the complex was suggested. The photodegredation of complex were study using photoreaction cell and preparednanoTiO2 catalyst in different conditions (concentration, temperatures, pH).The results show that the recation is of a first order with activation energy equal to (6.6512 kJ /mol).
... The electronic UV-Visible spectra obtained in DMF solutions exhibit one very broad absorption band in the 16,722 cm -1 region it is due to d-d transitions, a medium intense band at 27,932 cm -1 region for charge transition, and a strong sharp band at 34,013-37,174 cm -1 region for π→π* transition. [31][32][33][34] The electronic spectral data of the metal (II) complexes are presented in Table-2. Electronic spectrum of [Cu (BTHPC) 2 ] in high concentration (visible region) and low concentration (UV region) was given in Fig.3. ...
The cytotoxicity studies and MTT assay and antimicrobial activities are carried out in this research with transition metals.
... Os espectros Raman para os quatro materiais são altamente semelhantes, por se tratar do mesmo material semicondutor-base (Nb x O y ). No espectro apresentado na Figura 1, as bandas destacadas em azul são comuns a todos os materiais; uma banda larga em valores de deslocamento Raman bem baixos (< 200 cm -1 ) é bastante característica de sistemas amorfos ou nanoparticulados, com ordem em curtas distâncias, chamado de Boson Peak (BP), 30,31 e está presente em todos os espectros entre 62 e 65 cm -1 . Em valores de deslocamento Raman um pouco mais elevados, é possível observar bandas entre 200 -300 cm -1 características das deformações angulares de ligações Nb-O-Nb. ...
... The complexes showed an intense band at 269-314 nm, and a medium intense band at 342-368 nm due to ligand-to-metal charge transfer (LMCT) transition. The nickel(II) complexes (1-4) displayed three weak d-d bands at 780-790, 820-870, and 985-1,050 nm due to 3 A 2g ! 3 T 2g (F), 3 A 2g ! 3 T 1g and 3 A 2g ! 3 T 1g transitions, respectively, while the copper(II) complexes (5-8) displayed a broad band in the region 663-691 nm assigned to 2 Eg ! 3 T 2 g transition, [27][28][29][30] which supports the octahedral geometry around nickel(II) and copper(II) ions. The zinc(II) complexes (9)(10)(11)(12) showed only the ligand-to-metal charge transfer transition (LMCT) at 357-420 nm, and not displayed any d-d transition in the visible region owing to the d 10 configuration. ...
A series of 12 salicylidene‐based homoleptic nickel(II), copper(II) and zinc(II) complexes with the general formula [M(L1–4)2] (1–12) containing the tridentate ligands 2‐(((2‐(([1,1′‐biphenyl]‐3‐ylmethylene)amino)phenyl)imino)methyl)phenol (HL¹), 2‐(((2‐(([1,1′‐biphenyl]‐3‐ylmethylene)amino)phenyl)imino)methyl)‐4‐methoxyphenol (HL²), 2‐(((2‐(([1,1′‐biphenyl]‐3‐ylmethylene)amino)phenyl)imino)methyl)‐4‐ethoxyphenol (HL³) and 2‐(((2‐(([1,1′‐biphenyl]‐3‐ylmethylene)amino)phenyl)imino)methyl)‐4‐nitrophenol (HL⁴) have been synthesized and characterized by spectroscopic analysis. The tridentate nature of the ligands form an octahedral geometry around the central metal ion through the phenolic oxygen via deprotonation and two azomethine nitrogen atoms. Further, the charge transfer transitions taking place in the complexes have been explained using HOMO‐LUMO analysis. The in vitro cytotoxicity activity screened by WST assay against human metastatic (MDA‐MB‐231), hepatoma (HepG2) and colorectal adenocarcinoma (CaCo2) cancerous, and normal mouse fibroblast (NIH3T3) cell lines showed higher activity for the complexes 2, 6 and 10 with respect to the standard drug 5‐fluorouracil. The AO/EB, PI, Rh123 and DCFH‐DA staining results indicated that the complexes induced anticancer activity through apoptosis. Furthermore, the complexes interact with FGFR and P13Kγ kinase receptors through the hydrophobic, hydrogen bonding, π–π, σ–π, van der Waals and electrostatic interaction.
... The higher intensity bands in 1 and 2 may be attributed to the ligand-to-metal charge-transfer (LMCT) or intra ligand n-π*/π-π* transitions in these complexes [69]. Weak absorption bands at 410 nm for complex 1 and 403 nm for complex 2 may be attributed to d-d transitions [70]. ...
Two new manganese(III) Schiff base complexes MnL2N3 (1) and MnL2NCS (2) where HL is 4-bromo-2-[(Z)-{[2-(thiophene-2-yl)ethyl]imino}methyl]phenol) were synthesized and characterized by UV–Vis. absorption spectra, FT-IR, TGA Analyses, and single-crystal X-ray diffraction technique. Structural studies reveal that the metal sites in complexes 1–2 are six-coordinated by two phenoxy oxygen atoms, two imine nitrogen atoms of two moles of Schiff base ligand, HL, and two nitrogen atoms from the azide or one nitrogen atom and one sulphur atom from thiocyanate ligands, respectively. The geometry around the metal center is twisted octahedral geometry with a MnN4O2 (for 1) and MnN3O2S (for 2) chromophore. Hirshfeld surfaces associated with 2D fingerprint plots have been used to analyze intermolecular interactions in crystal packing. Crystal packing of both complexes shows the interchain π⋯π stacking interactions between one-dimensional polymeric chains.
... The diffuse reflectance spectra for the copper(II) complexes [Cu(onz) 2 Cl 2 ] and [Cu(onz) 2 Br 2 ] showed a multicomponent electronic transition band, centered at 12,560 and 12,450 cm −1 , respectively, characteristic of a pseudotetrahedral geometry [41]. Similar bands were observed for [Cu(cenz) 2 ...
Tetrahedral copper(II) and zinc(II) coordination compounds from 5-nitroimidazole derivatives, viz . 1-(2-chloroethyl)-2-methyl-5-nitroimidazole (cenz) and ornidazole 1-(3-chloro-2-hydroxypropyl)-2-methyl-5-nitroimidazole (onz), were synthesized and spectroscopically characterized. Their molecular structures were determined by X-ray diffraction studies. The complexes [Cu(onz) 2 X 2 ], [Zn(onz) 2 X 2 ], [Cu(cenz) 2 X 2 ] and [Zn(cenz) 2 X 2 ] (X ⁻ = Cl, Br), are stable in solution and exhibit positive LogD 7.4 values that are in the range for molecules capable of crossing the cell membrane via passive difussion. Their biological activity against Toxoplasma gondi was investigated, and IC 50 and lethal dose (LD 50 ) values were determined. The ornidazole copper(II) compounds showed very good antiparasitic activity in its tachyzoite morphology. The interaction of the coordination compounds with DNA was examined by circular dichroism, fluorescence (using intercalating ethidium bromide and minor groove binding Hoechst 33258) and UV–Vis spectroscopy. The copper(II) compounds interact with the minor groove of the biomolecule, whereas weaker electrostatic interactions take place with the zinc(II) compounds. The spectroscopic data achieved for the two series of complexes (namely with copper(II) and zinc(II) as metal center) agree with the respective DNA-damage features observed by gel electrophoresis.
Graphical abstract
... The splitting of the υ(N-O) vibration into two bands confirms the presence of two non-equivalent intramolecular and inter-molecular hydrogen bonding 24 . The ligand spectrum also displayed three peaks at 1687, 1637 and 1617 cm -1 assignable to υ(C=O), υ(C=N)imine and υ(C=N)oxime respectively [32][33][34][35] Furthermore the υ(C=N)imine and υ(C=N)oxime bands observed at 1637 and 1617 cm -1 in the ligand spectra, respectively, were shifted to lower frequency by 6-13 and 9-17 cm -1 respectively suggesting the participation of two azomethine groups in the coordination process. Ir spectral data of complexes (7, 9, 11, 12, 14, 19 and 22) revealed the presence of the υ(OH)oxime, however it is subjected to a shift to higher or lower wavenumber comparing to the ligand referring to its participation in the metal coordination. ...
New binary and ternary metal (II) complexes derived from N, N-bidentate Oxime ligand were prepared. Physicochemical studies revealed that the ligand coordinates the metal ion in a bidentate mode through the two nitrogen atoms of the azomethine and oxime groups. All metal complexes were found to be non-electrolytic in nature as suggested by molar conductance measurements, they adopted a tetragonal distorted octahedral geometry around metal ions except complexes (Zn(II) complex (14), Sr(II) complexes (16,17) which adopted a tetrahedral geometry). The cytotoxicity activity of the ligand as well as its metal complexes were evaluated against human liver cancer (Hep-G2) and human breast cancer (MCF-7). In is worth noting, the cytotoxic activity was enhanced upon complexation of the ligand to the metal ions (except complexes in Fe(II) complex (5), Zn(II) complex (14)). It was interestingly found that the complexes Hg(II) complex (20) and U(II) complex (23), formed in (2L: M) ratio, recorded the highest cytotoxicity against Hep-G2 with IC50 2.79 and 3.21 respectively. On the other hand, complexes Cu(II) complex (10) and Cd(II) (19) recorded moderate IC50 values (11.6 and 11.7 respectively) against MCF-7, in the time that other tested complexes showed a weak cytotoxicity against the same cell line.
... Zinc(II) complex (9), uranyl (II) complex ( Table-4. The spectra of copper (II) complexes (2) and (3) are characteristic of species, d 9 , configuration and having axial type of a d (x2-y2) ground state which is the most common for copper (II) complexes 65,66 . The complex (2) shows broad signals in the low and high field regions indicating spinspin interactions takeplace between Cu (II) ions through deprotonated hydroxyl group. ...
The ligand 4-(di 1,3-(2-hydroxybenzylidene) guanidino) benzoic acid reacted with Cr (III), Mn (II), Fe (III), Co (II), Ni (II), Cu (II), Zn (II), Cd (II), Sr (II), Hg (II), Ag (I), Tl (I), ZrO (II) and UO 2 (II) ions forming octahedral or square planar complexes. These complexes have been synthesized and characterized by elemental analyses, IR, UV-Vis spectra, mass spectra (ligand and its cadmium(II) complex), 1 H-NMR spectra (ligand and its mercury(II) complex), magnetic moments, conductances, thermal analyses (DTA and TGA) and ESR measurements. The IR data show that, the ligand behaves as dibasic hexadentate, (2), (4), (5), (6), (12) and (13) , dibasic tetradentate, (3), (8), (9) and (10) mono-basic tetradentate, (7), (11), (14) and (15). Molar conductances in DMF indicate that, the complexes are non-electrolyte. The ESR spectra of solid Cu (II) complex (3) at room temperature show axial type symmetry, indicating a d (x2-y2) ground state with significant covalent bond character in square planar geometry. However, Cu Spectroscopic … Saad El-Tabl et al. 3774 (II) complex (2) shows broad signals in the low and high field regions indicating spin exchange interactions take place between Cu (II) ions through deprotonated hydroxyl group. Complexes of Mn (II) (5) , Co(II), (6), Cr (III), (12) and Fe (III), (13) show isotropic type, indicating octahedral structure around the metal ion. Cu (II) complex (2), Ni (II) complex (4), UO 2 (II) complex (7), Hg (II) complex (8) and Fe (III) complex (13) showed inhibitory effect on liver carcinoma (HePG-2 cell line) in comparing with the standard drug (Sorafenib), Also, Cu (II) complex (3) Ni (II) complex (4) and Cd (II) complex (10) show Antibacterial activity. Hg (II) complex (8), Cd (II) complex (10) and Tl (I) complex (11) show antifungal activity.
... The spectrum of the ligand showed broad bands centered at 3450 and 3373 cm -1 which assigned to υ(OH). However, strong broad bands appeared in the 3600-3320 and 3380-2670 cm -1 ranges confirmed the presence of non-equivalent intra and intermolecular hydrogen bondings [14][15][16][17][18]. Also, the spectrum of the ligand displayed tow bands at 1700 and 1650cm -1 assignable to υ(C=O) and υ(C=N) respectively [19][20][21][22] . Medium bands were observed at 1540, 1450, 818 and 750 cm -1 which are related to vibration of ν(Ar) ring. ...
New binary Cu(II), Mn(II), Ag(I), Fe(III), Co(II), Ni(II), Zn(II) ,Cd(II), Mg(II), Al(III) and Ca(II) metal complexes derived from (Z)-N'-(2-hydroxybenzylidene)-2-((Z)-(2-hydroxybenzylidene)amino)pro p-anehydrazide ligand were prepared. Physicochemical studies (IR, UV-Vis, Mass, 1H-NMR, Magnetism , DTA and TGA, conductivity and ESR) were carried out. The measurements revealed that, the ligand coordinated to the metal ion in a neutral hexadentate or dibasic hexadentate mode through nitrogen atoms of imino group and oxygen atom of the hydroxyl group in protonated or non-protonated form. All metal complexes are non-electrolytic in nature as suggested by molar conductance measurements. The complexes are adopted to be tetragonal distorted octahedral geometry around the metal ions. The cytotoxic activity of the ligand as well as some of its metal complexes was evaluated against breast cancer (MCF-7). It is worth noting, the cytotoxic activity was enhanced upon complexation. Also, it was interestingly found that, Zn(II) complex (7) recorded the highest IC50 value against MCF-7. However, the other tested complexes showed a weak cytotoxicity against the same cell line compared with a standard drug (vinblastine sulfate).The molecular docking of the tested. INDRODUCTION Complexes was carried out to know the number of bonding and the energy with the breast gene. Amides and their derivatives constitute a amount class of compounds in organic chemistry. These compounds have interesting biological properties such as anti-inflammatory, analgesic, anticonvulsant, antituberculous, antitumor, anti-HIV and antimicrobial activity [1]. Amides are important compounds for drug design, as possible ligands for metal complexes, organocatalysis and also for the syntheses of heterocyclic compounds [2]. The ease of preparation, increased hydrolytic stability relative to imines, and tendency toward crystallinity are all desirable characteristics of amides. Due to these positive traits, amides had been under study for a long time, but much of their basic chemistry remains unexplored. Amides ligands create an environment similar to the one present in biological systems usually by making coordination through oxygen and nitrogen atoms. Various important properties of carbonic acid amides, along with their applications in medicine and analytical chemistry, have led to increased interest in their complexation characteristics with transition metal ions [3]. The DOI
This study aims to advance the field of green chemistry and catalysis by exploring alternatives to conventional non-renewable energy sources. Emphasis is placed on hydrogen as a potential fuel, with a focus on the catalytic properties of Ni(II) complexes when coordinated with o-phenylenediamine and diimine ligands. We report the synthesis and comprehensive characterization, with various physical and spectroscopic techniques, of three heteroleptic Ni(II) complexes: [Ni(1,10-phenanthroline)(o-phenylene diamine)] (1), [Ni(2,2-dimethyl-2,2-bipyridine)(o-phenylene diamine)] (2), and [Ni(5,5-dimethyl-2,2-bipyridine)(o-phenylene diamine)] (3). The catalytic activity of these complexes for hydrogen evolution was assessed through photochemical studies utilizing visible light irradiation. Two distinct photosensitizers, fluorescein and quantum dots, were examined under diverse conditions. Additionally, their electrocatalytic behavior was investigated to elucidate the hydrogen evolution reaction (HER) mechanism, revealing a combined proton-coupled electron transfer (PCET)/electron-coupled proton transfer (ECPT) mechanism attributed to the chemical nature of the diamine ligand. The influence of ligand substituent position, ligand chemical nature, and photosensitizer type on catalytic performance was systematically studied. Among the complexes investigated, complex 2 demonstrated superior catalytic performance, achieving a turnover number (TON) of 3357 in photochemical experiments using fluorescein as a photosensitizer. Conversely, complex 1 exhibited the highest TON of 30,066 for HER when quantum dots were employed as the photosensitizer.
Advancements in scientific research have always been the driving force behind human progress, unlocking new realms of understanding and pushing the boundaries of what is possible. In the dynamic and ever-evolving field of chemical science, the quest for knowledge and innovation is relentless. "Advances in Chemical Science: Exploring New Frontiers" stands as a testament to the collective efforts of pioneering researchers who have ventured into uncharted territories, pushing the frontiers of chemical knowledge to unprecedented heights. This edited volume serves as a comprehensive compendium of the latest breakthroughs and emerging trends in chemical science. As the scientific community continues to unravel the complexities of matter and explore the intricacies of chemical interactions, this book provides a snapshot of the diverse and groundbreaking research that defines the contemporary landscape of the discipline. The chapters contained within this volume reflect the multidisciplinary nature of modern chemical science, encompassing a wide array of subfields such as organic chemistry, inorganic chemistry, physical chemistry, biochemistry, nano technology, chemical biology and materials science. From fundamental theoretical studies to practical applications, each contribution illuminates a unique facet of chemical science, contributing to the mosaic of knowledge that shapes our understanding of the world around us. The journey through "Advances in Chemical Science" begins with a thought-provoking exploration of theoretical frameworks that underpin our understanding of chemical phenomena. From there, the reader is guided through a spectrum of research endeavors, ranging from the synthesis of novel compounds to the design of innovative materials with tailored properties. The interplay between theory and experiment, a hallmark of successful scientific inquiry, is exemplified in each chapter, underscoring the collaborative efforts of theorists and experimentalists alike. In addition to traditional areas of study, this volume also delves into the burgeoning intersections of chemical science with other disciplines. The exploration of the interface between chemistry and biology, the development of environmentally sustainable practices, and the application of advanced analytical techniques showcase the dynamic and interconnected nature of contemporary chemical research. I hope that "Advances in Chemical Science: Exploring New Frontiers" will inspire researchers, students, and enthusiasts to delve into the fascinating world of chemical science. May the discoveries within these pages spark new ideas, foster collaborations, and ignite a passion for pushing the boundaries of knowledge. Together
A new doubly carboxylato bridged Co(II) dinuclear complex, [Co(bdtbpza)(NCS)]2 (1)
is afforded in satisfactory yield by employing a ‘scorpionate’ type precursor, bdtbpza
{bis-(3,5-di-tert-butylpyrazol-1-yl)acetate} and structurally characterized. Single
crystal X-ray diffraction analysis reveals that, in 1, each Co(II) is penta-coordinated
subjecting a distorted trigonal bipyramidal geometry with the coordination
environment of N3O2. There prevails a weak antiferromagnetic coupling within the
Co(II) ions in 1, based upon the isotropic spin Hamiltonian H = -J (S1·S2) for Si = 3/2
system. While evaluating the spin density distribution and the mechanism for the
magnetic exchange coupling, the DFT analysis is accomplished and it is evident with
the magnetic data. Electrochemical H2 evolution study, involving cyclic voltammetry
(CV), controlled potential electrolysis (CPE) and gas chromatographic (GC) analysis
of graphite electrode modified with cobalt complex in neutral aqueous solution
reveals the high catalytic activity of the complex with low overpotential toward H2O
reduction. The Faradaic efficiency of the catalysis is found to be 83.7% and the
di-cobalt catalyst-modified electrode displays quite an interesting H2 evolution
activity when compared with that of bare electrodes. These results are encouraging
towards a future potential application of 1 in the field water splitting catalysis.
Изучена широкополосная (1000–1600 нм) ИК-фотолюминесценция поликристаллических образцов корунда (α-Al 2 O 3 ), содержащих примесные ионы меди, а также дополнительные солегирующие ионы элементов в степени окисления 4+: Si 4+ , Ge 4+ , Ti 4+ , Zr 4+ , Hf 4+ , Sn 4+ . Показано, что интенсивность ИК-фотолюминесценции корунда при легировании только медью весьма незначительна и резко усиливается при дополнительном легировании некоторыми четырехзарядными катионами. Наибольшее усиление ИК-фотолюминесценции примесных ионов Cu 2+ получено при солегировании катионами Ti 4+ , Ge 4+ и Sn 4+ . По-видимому, эти ионы обеспечивают зарядовую компенсацию при совместном с ионом Cu 2+ вхождении в кристаллическую решетку корунда и процесс замещения выглядит так: 2Al 3+ → Cu 2+ + M 4+ ; M 4+ = Ti 4+ , Ge 4+ , Sn 4+ … . Подобным образом вводимые дополнительно в решетку корунда солегирующие четырехзарядные ионы повышают растворимость Cu 2+ в α-Al 2 O 3 , что ведет к усилению фотолюминесценции соответствующего материала.
Two new coordination compounds comprising Mn(II) and Cu(II) viz. [Mn(bz)2(Hdmpz)2(H2O)] (1) and [Cu(crot)2(Hdmpz)2] (2) (where, bz = benzoate; crot = crotonate; Hdmpz = 3, 5-dimethyl pyrazole) were synthesized and characterized. The characterization involved a single crystal X-ray diffraction technique, FT-IR spectroscopy, electronic spectroscopy, TGA, and elemental analyses. Compounds 1 and 2 crystallize as mononuclear entities of Hdmpz with penta-coordinated Mn(II) and hexa-coordinated Cu(II), respectively. These complexes exhibit distorted trigonal bipyramidal and distorted octahedral geometries, respectively. A crystal structure analysis of compound 1 elucidates the existence of C–H⋯π and π-stacking interactions alongside O–H⋯O, N–H⋯O, and C–H⋯O H-bonding interactions contributing to the stabilization of the compound’s layered assembly. Similarly, in compound 2, the crystal structure stability is attributed to the presence of hydrogen bonding in conjugation with π-stacking interactions. We conducted theoretical investigations to analyze π⋯π, H-bonding, and antiparallel CH···π non-covalent interactions observed in compounds 1 and 2. DFT calculations were performed to find out the strength of these interactions energetically. Moreover, QTAIM and non-covalent interaction (NCI) plot index theoretical tools were employed to characterize them and evaluate the contribution of the H-bonds.
Three tridentate imine ligands containing N2S donors were synthesized via Schiff condensation between derivatives of both amino triazine and 2-carbonyl pyridine. The reaction of these ligands with CuCI2 in a molar ratio of 1:1 provides three Cu(II) complexes with the general formula [CuLn·Cl2]. Analytical, electrical, magnetic, and spectroscopic studies were used to assign the molecular formulae of these metallic chelates. Density function theory (DFT) calculations confirmed the structural analysis results obtained from spectroscopic studies. The various characterization techniques used demonstrated the pentacoordinated slightly distorted square pyramidal structure for the present Cu(II) complexes 1, 2, and 3. Measurements of cyclic voltammetry were done in methanol to define the electrochemical behavior of the current Cu(II) complexes. The biomimetics of catechol oxidase (C.O.) and phenoxazinone synthase (PHS) have been studied in the aerobic oxidation of some phenolic substrates, such as 3,5-di-tert-butylcatechol (3,5-DTBCH2) and ortho-aminophenol (o-APH3). The three candidate oxidase mimetics showed promising activity in the order 3>1>2. The catalytic activity related to the structural properties of existing oxidase mimetics was discussed. The driving force (−ΔG°) controlling the redox reactions of the present biomolecules was calculated from the redox data of Cu(II) complexes 1, 2, and 3. The potential catalytic reaction pathway for the oxidation of the studied phenolic substrates was discussed.
The present study involves the synthesis and characterization of complexes of [Cr(III), Fe(III), Co(II), and Ni(II)] with Schiff base and L-proline using 4-dimethylaminobenzaldehyde and 4-aminoantipyrine as reactants. The complexes have been characterized using various spectroscopic techniques such as infrared and UV-Vis spectroscopy, mass spectrometry, melting point and conductivity measurements. The formulated complexes are [M(L)(Pro)2]Cl, where M=Fe(III),Cr(III), and [M(L)(Pro)2], where M= Co(II), Ni(II). The ligands Schiff base and L-proline have been found to act as bidentate chelating agents. L-proline coordinates with the amine group's carboxyl group and nitrogen atom, while Schiff base coordinates through the nitrogen and oxygen atoms. The complexes have been assigned an octahedral geometry based on electronic spectral and magnetic moment studies. Furthermore, The results of the biological activity of the complexes and ligands showed good results against Gram +ve bacteria and Gram −ve bacteria.
Human calprotectin (CP) is an innate immune protein that participates in the metal-withholding response to infection by sequestering essential metal nutrients from invading microbial pathogens. CP is comprised of S100A8 (α subunit, 10.8 kDa) and S100A9 (β subunit, 13.2 kDa). Two transition-metal binding sites of CP form at the S100A8/S100A9 dimer interface. Site 1 is a His3Asp motif comprised of His83 and His87 from the S100A8 subunit and His20 and Asp30 from the S100A9 subunit. Site 2 is an unusual hexahistidine motif composed of S100A8 residues His17 and His27 and S100A9 residues His91, His95, His103, and His105. In the present study, the His3Asp and His6 sites of CP were further characterized by utilizing Co2+ as a spectroscopic probe. Magnetic circular dichroism spectroscopy was employed in conjunction with electron paramagnetic resonance spectroscopy and density functional theory computations to characterize the Co2+-bound S100A8(C42S)/S100A9(C3S) CP-Ser variant and six site variants that allowed the His3Asp and His6 sites to be further probed. Our results provide new insight into the metal-binding sites of CP-Ser and the effect of amino acid substitutions on the structure of site 2.
Disalicylaldehyde fumaroyldihydrazone (slfhH4) interacts with Mn(OAc)2·4H2O in presence of KOH in the methanolic medium giving [MnIV(slfh)(A)2]·2H2O and [MnIV(slfh)(NN)] (where A = H2O (1), pyridine (py), 2-picoline (2-pic), 3-picoline (3-pic), 4-picoline (4-pic), NN = 2, 2′-bipyridine, (bpy) and 1, 10- phenanthroline, (phen)). All the complexes are non-electrolytes. The complexes have been characterized by elemental analyses, molecular mass determinations, molar conductance data, magnetic moment data, electronic, IR and EPR spectroscopic studies. Structural assessments of the complexes have been carried out based on magnetic moment, electronic, IR and EPR spectral data. The magnetic moment, electronic and electron paramagnetic resonance spectral studies correspond to Mn(IV) centre within a six-coordinate octahedral geometry around the manganese centre. The dihydrazone functions as a tetradentate ligand chelating the manganese(IV) ion present in octahedral geometry with anti-cis configuration in enol form. The cyclic voltammetric technique has been used for studying the electrochemical behaviour of the ligand and complexes thereof. The antibacterial activity of ligand and its complexes has been tested against Gram-positive bacteria, Staphylococcus aureus, Bacillus cereus and Gram-negative bacteria, E. coli, Klebsiella pneumoniae and Pseudomonas vulgaris.
With increasing interest in nickel-based electrocatalysts, three heteroleptic Ni(II) dithiolate complexes with the general formula [Ni(II)L(L’)2] (1-3), L= 2-(methylene-1,1’-dithiolato)-5,5’-dimethylcyclohexane-1,3-dione; and L’ = triphenylphosphine (1), 1,2-bis(diphenylphosphine)ferrocene (DPPF) (2), 1,2-bis(diphenylphosphine)ethane (DPPE) (3)...
A novel Schiff-base derived from N,N \-diphenylmethane tetraamine and its Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Pb(II), Hg(II), Bi(III) and Zr(IV) complexes have been prepared and characterized by elemental and thermal analyses, magnetic and conductivity measurements as well as spectroscopic techniques (1 H-NMR, IR, UV. Vis, |Mass and ESR). Spectral data show that, the ligand behaves as a neutral tetradentate bonding to the metal ions via two nitrogen and two oxygen atoms in all metal complexes except Zr(IV) complexes (18,19) that adopt a neutral bidentate fashion. The molar conductance values of the complexes in DMF are commensurate with their non-electrolytic nature. The ESR spectra of solid complexes show anisotropic or isotropic type with covalent or ionic bond character. The antibacterial activities results show that, most metal complexes exhibit more inhibitory effects towards both gram-positive Bacillus subtilis and Escherichia Coli than the parent organic ligand. The cytotoxicity of the compounds was found to be a concentration dependent.
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