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The SEM photos of nano-particles of macrocyclic metal chelate formed in a self-assembly process in the MHF GIM in the Co(II)–dithiooxamide–formaldehyde (A), Co(II)–dithiooxamide–glyoxal (B), Ni(II)–dithiooxamide–formaldehyde (C), Ni(II)–dithiooxamide–glyoxal (D), Ni(II)–thiocarbohydrazide–formaldehyde (E), Ni(II)–thiocarbohydrazide–acetone (F), Cu(II)–dithiooxamide–formaldehyde (G), Cu(II)–dithiooxamide–glyoxal (H), Cu(II)–thiocarbohydrazide–formaldehyde (I) and Cu(II)–thiocarbohydrazide–diacetyl (J).
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![Molecular structures of [CoL11] (left) and [ZnL11] (right).](profile/Oleg-Mikhailov/publication/260155079/figure/fig10/AS:213802764247047@1427985959103/Molecular-structures-of-CoL11-left-and-ZnL11-right_Q320.jpg)
![Molecular structures of [NiL12] (left) and [CuL12] (right).](profile/Oleg-Mikhailov/publication/260155079/figure/fig11/AS:213802764247062@1427985959293/Molecular-structures-of-NiL12-left-and-CuL12-right_Q320.jpg)
![Molecular structures of [CuL15] (left) and [ZnL15] (right).](profile/Oleg-Mikhailov/publication/260155079/figure/fig12/AS:213802764247069@1427985959422/Molecular-structures-of-CuL15-left-and-ZnL15-right_Q320.jpg)
This article is a review of recent developments in the self-assembled nanostructures based on chelate coordination compounds. Molecular nanotechnologies of self-assembly of 3d-element aza- and thiazametalmacrocyclic complexes that happen in nanoreactors on the basis of metal hexacyanoferrate(II) gelatin-immobilized matrix under their contact with w...
Citations
... Therefore, these biopolymer (host)/immobilized nanoparticle (guest) systems serve as a convenient medium for the realization of several chemical processes that are often unavailable under the so-called "traditional" performance conditions of chemical reactions in solutions or solid phase. Examples of these systems include gelatin-immobilized ferrocyanides (FOC) of transition metals, comprising nanoreactors for the synthesis of new compounds [4], or the gelatincalcium phosphate system [5], which can be used for creating ceramic composite materials in bone tissue engineering [5][6][7]. ...
Data related to the fabrication of hybrid materials based on the polysaccharide chitosan were systematized and reviewed. The possibility of using chitosan as a “host” matrix for in situ synthesis of inorganic compounds for the preparation of various types of composite materials were investigated. Coprecipitation of metal oxides/hydroxides (Fe, Ni, Al, Zr, Cu and Mn) with chitosan was carried out through the alkalinization of solutions containing metal salts and chitosan, with the addition of ammonia or alkali solutions, homogeneous hydrolysis of urea, or electrophoretic deposition on the cathode. The synthesis of transition metal ferrocyanides and hydroxyapatite was achieved from precursor salts in a chitosan solution with simultaneous alkalinization. The mechanism of composite formation during the coprecipitation process of inorganic compounds with chitosan is discussed. Composite materials are of interest as sorbents, coatings, sensors, and precursors for the production of ceramic and electrode materials.
... Details of the production of Ag-NP using such a specific method were presented in [200,201]. The idea that in the specific conditions of chemical processes in the gelatin matrix, as well as due to the above-mentioned specific structure of the gelatin itself, nanoparticles of a wide variety of chemical compounds can be formed in it, was expressed in a number of earlier works, particular in reviews [195][196][197]202,203]. ...
The data on the specifics of synthesis of elemental silver nanoparticles (Ag-NP) having various geometric shapes (pseudo spherical, prismatic, cubic, trigonal-pyramidal, etc.), obtained by using various biological methods, and their use in biology and medicine have been systematized and generalized. The review covers mainly publications published in the current 21st century. Bibliography: 262 references.
... Based on these observations, we hypothesize that increased relaxivity is mainly related to the creation of water domains or clusters (water compartments) around the CA within the polymer matrix. In fact, biopolymer systems contain intermolecular cavities that can be considered as molecular nano-domains in which various self-assembly processes can be implemented in principle [80]. The formation of peculiar structures within these cavities can be associated with thermodynamic transitions and it is a characteristic of many metallopolymer systems [81,82]. ...
Recently, rational design of a new class of contrast agents (CAs), based on biopolymers (hydrogels), have received considerable attention in Magnetic Resonance Imaging (MRI) diagnostic field. Several strategies have been adopted to improve relaxivity without chemical modification of the commercial CAs, however, understanding the MRI enhancement mechanism remains a challenge.
Methods: A multidisciplinary approach is used to highlight the basic principles ruling biopolymer-CA interactions in the perspective of their influence on the relaxometric properties of the CA. Changes in polymer conformation and thermodynamic interactions of CAs and polymers in aqueous solutions are detected by isothermal titration calorimetric (ITC) measurements and later, these interactions are investigated at the molecular level using NMR to better understand the involved phenomena. Water molecular dynamics of these systems is also studied using Differential Scanning Calorimetry (DSC). To observe relaxometric properties variations, we have monitored the MRI enhancement of the examined structures over all the experiments. The study of polymer-CA solutions reveals that thermodynamic interactions between biopolymers and CAs could be used to improve MRI Gd-based CA efficiency. High-Pressure Homogenization is used to obtain nanoparticles.
Results: The effect of the hydration of the hydrogel structure on the relaxometric properties, called Hydrodenticity and its application to the nanomedicine field, is exploited. The explanation of this concept takes place through several key aspects underlying biopolymer-CA's interactions mediated by the water. In addition, Hydrodenticity is applied to develop Gadolinium-based polymer nanovectors with size around 200 nm with improved MRI relaxation time (10-times).
Conclusions: The experimental results indicate that the entrapment of metal chelates in hydrogel nanostructures offers a versatile platform for developing different high performing CAs for disease diagnosis.
... In most cases, however, such an image consists of microparticles, but in some cases, as a result of the processes of so-called "re-precipitation" of elemental silver, as it was shown in a recently published paper [57], the formation of Ag-NP occurs. However, the idea that due to specific conditions of chemical processes in gelatin films, as well as the specific structure of this high-molecular compound itself, nanoparticles of the most diverse chemical compounds would appear in it, was expressed in a number of works, in particular, in review articles [58][59][60][61][62], even before the publication of the paper [57]. With using this approach, the synthesis of pseudo-spherical Ag-NP in the gelatin matrix was realized in [63][64][65][66]. ...
Background
The data on the specific synthesis of elemental silver nanoparticles (Ag-NP) having the forms of various geometric bodies (pseudo spherical, prismatic, cubic, trigonal-pyramidal, etc.), obtained by various methods, have been systematized and generalized.
Objective
It is noted that the forms and sizes of Ag-NP are greatly dependant on the conditions in which they are formed.
Method
Comparison of the data of the characteristics of silver nanoparticles obtained by chemical, physicochemical and biological methods has been made.
Results
It has been shown that form and size of produced Ag-NP depend strongly on the such factors as temperature, the concentration of silver(I) containing precursor, pH of the solution, the molar ratio between capping agent and silver(I) containing precursor, reducing agents etc., and, also, on the method used for Ag-NP synthesis (chemical, physicochemical or biological).
Conclusion
It has also been noted that biological methods of synthesis of Ag-NP are generally more preferable in comparison with the chemical and physicochemical methods. The review covers mainly publications published in the last 20 years.
... In most cases, however, such an image consists of microparticles, but in some cases, as a result of the processes of so-called "re-precipitation" of elemental silver, as it was shown in a recently published paper (Mikhailov 2017), the formation of Ag-NPs occurs. However, the idea that due to specific conditions of chemical processes in gelatin films, as well as the specific structure of this high-molecular compound itself, NPs of the most diverse chemical compounds would appear in it was expressed in a number of works, in particular, in review articles (Mikhailov 2010, 2013, 2014a,b, Mikhailov et al. 2015, even before the publication of the paper (Mikhailov 2017). Using this approach, the synthesis of pseudospherical Ag-NPs in the gelatin matrix was realized in Mikhailov et al. (2005Mikhailov et al. ( , 2008Mikhailov et al. ( , 2013, Mikhailov and Naumkina (2010). ...
The data on the specific synthesis of elemental silver nanoparticles having the forms of various geometric bodies (pseudo spherical, prismatic, cubic, trigonal-pyramidal, etc.), obtained by various chemical, physicochemical, and biological methods, have been systematized and generalized. This review covers mainly publications published in the current 21st century.
... In recent years, nanotechnology has emerged as one of the most key technologies in the field of metal extraction, catalysis, pharmacy, biotechnology, electronics, etc. [10][11][12]. The fabrication of nanostructured chelated sorbents, particularly for metal ion extraction, is emerging as an important field of analytical chemistry due to their unique properties [13]. ...
This review article gives an insight into recent developments in chelating agents modified nanostructures in metal extraction and catalysis. The ability of functionalization by anchoring specific functional groups on the surface of nanostructures makes it possible to synthesize different types of desired chelated nanostructures for their use as catalysts and metal ion scavengers. Keeping these aspects in outlook this review emphasizes mainly on the synthesis of chelating agent functionalized nanostructures and their applications in the field of metal ion extraction and catalysis. The review article provides comprehensive information about the work that has been done in the past 5 years in the field of metal ion extraction and catalysis using chelating agent modified nanoparticles.
... Being obtained from the natural fibrillary fiber of the protein collagen, gelatin could be a serious candidate among these naturally occurring reagents. It is a polydispersed mixture of lowmolecular peptides composed of 18 natural amino acids, having a molecular mass of 50000-70000 [19]. The molecules of this highmolecular compound consist of three polypeptide α-chains with identical molecular weights. ...
... The molecules of this highmolecular compound consist of three polypeptide α-chains with identical molecular weights. Mikhailov [19] proposes the lefthanded spiral structure for each α-chain. According to Othmer [20] the left handed helical conformation of the proteins, as well as the extensive number of double bonded oxygen atoms and nitrogen can facilitate the complexation and stabilization of inorganic compounds. ...
... According to Othmer [20] the left handed helical conformation of the proteins, as well as the extensive number of double bonded oxygen atoms and nitrogen can facilitate the complexation and stabilization of inorganic compounds. In this regard, gelatin made the object of study for some very recent researches related to the preparation of nanoparticles [19,[21][22][23][24]. ...
The aim of the present work was to prepare zirconia-based nanopowders using the sol-gel method. Both gelatin as structure directing agent and Ce as dopant have been used, in order to create nanostructures with active surface, able to confer optical properties to the obtained materials. Different characterization methods (thermal analysis, infrared spectroscopy, X-ray diffraction, scanning electron microscopy, BET surface area and porosity and fluorescence assay) have been used to establish the effects of organic additive and dopant on the properties of the obtained nanopowders. They revealed that all the prepared powders are nanometric and consist only of monoclinic ZrO2, except the Ce-doped one, where a Zr1−xCexO2 type solid solution was assumed to be formed. The sensor platform abilities of the nanopowders have been tested using Rhodamine B as fluorescent detector. It was demonstrated that both gelatin as template (due to pores generation) and Ce as dopant (due to induced lattice defects) influence the optical properties of the obtained oxide powders. This allows us to consider them interesting candidates for the sensors platform.
The data have been systematized and generalized on the specific synthesis of elemental silver nano-sized crystals (Ag-NC) having the forms of various geometric bodies (pseudo spherical, prismatic, cubic, trigonal-pyramidal, etc.), obtained by various chemical, physicochemical and biological methods. It has been noted, that the form of the synthesized Ag-NC can be controlled by changing the thermodynamic and kinetic parameters at each key stage of the synthesis (nucleation, seeding, and growth). Moreover, the size range of spherical and cubic silver nanocrystals can be influenced by either physical, chemical or biological methods during the synthesis, but such forms as nanorods, nanowires and nanobars can only be synthesized by chemical or physical methods at the present time. The review covers articles comprehensively mainly published in the last 20 years.
Low‐dimensional (0/1/2 dimension) transition metal carbides (TMCs) possess intriguing electrical, mechanical, and electrochemical properties, and they serve as convenient supports for transition metal catalysts. Large‐area single‐crystalline 2D TMC sheets are generally prepared by exfoliating MXene sheets from MAX phases. Here, a versatile bottom‐up method is reported for preparing ultrathin TMC sheets (≈10 nm in thickness and >100 μm in lateral size) with metal nanoparticle decoration. A gelatin hydrogel is employed as a scaffold to coordinate metal ions (Mo5+, W6+, Co2+), resulting in ultrathin‐film morphologies of diverse TMC sheets. Carbonization of the scaffold at 600 °C presents a facile route to the corresponding MoCx, WCx, CoCx, and to metal‐rich hybrids (Mo2−xWxC and W/Mo2C–Co). Among these materials, the Mo2C–Co hybrid provides excellent hydrogen evolution reaction (HER) efficiency (Tafel slope of 39 mV dec−1 and 48 mVj = 10 mA cm‐2 in overpotential in 0.5 m H2SO4). Such performance makes Mo2C–Co a viable noble‐metal‐free catalyst for the HER, and is competitive with the standard platinum on carbon support. This template‐assisted, self‐assembling, scalable, and low‐cost manufacturing process presents a new tactic to construct low‐dimensional TMCs with applications in various clean‐energy‐related fields. Transition metal ions (Mo, Co, W) self‐organize within a gelatin template into a lamellar‐nanostructured soft material (metallohydrogel). Subsequent carbonization at moderate temperatures in a reducing atmosphere (600 °C) yields ultrathin (≈10 nm) and large (≈100 μm) 2D transition metal carbide sheets with high conductivity and rich active sites, which are ideal for the hydrogen evolution reaction (HER).
Molecular structures of various d -element M(II) ion chelates with compartmental ( N , N )-, ( N , O )-, and ( N , S )-donor atomic ligands forming as a result of complexing with M(II) three or four articulated metal chelate cycles have been systematized and discussed in detail. It has been shown that, on the whole, such metalmacrocyclic compounds, as a rule, have molecular structures with non-coplanar chelate nodes and non-coplanar macrocycles. The review covers the period 2000–2017.
