Ryszard Jakubas

University of Wroclaw | WROC · Faculty of Chemistry

s The guanidinium derivatives [C(NH2)3]3Bi2I9 (GBI) and [C(NH2)3]3Sb2I9 (GSI) are promising compounds from the viewpoint of their electrooptical and semiconducting properties. In this paper we present the optical, dielectric, UV–Vis, Raman and ¹H NMR (spin-lattice relaxation time, T1, and second moment, M2) results of studies on GBI and GSI. The te...

Propellanes form a large family of compounds having propeller-like shape. Members of this family, which crystallize in noncentrosymmetric space group, could be interesting for second-order nonlinear optics, however their properties have not gained the proper attention yet. Here, we report on 16,20-dinitro-(3,4,8,9)-dibenzo-2,7-dioxa-5,10-diaza[4.4....

4-aminopyridinium analogue, [4-NH2PyH]7[BiCl6]2Cl has been synthesized and characterized by single-crystal X-ray diffraction at 100 K, calorimetric, dilatometric and dielectric studies. The crystal structure is centrosymmetric with the monoclinic space group, P21/n. It consists of two discrete [BiCl6]³⁻ octahedra, one loose Cl⁻ anion and seven, par...

A description of the thermal, structural, 1H NMR, electric and optical properties of four organic-inorganic hybrids, haloantimonates(III) and halobismuthates(III), based on homopiperidinium cation: (C6H14N)2SbCl5 (abbrev. HSC), (C6H14N)2SbBr5 (HSB), (C6H14N)2BiCl6[H3O] (HBC), (C6H14N)2BiBr5 (HBB), is presented. The common feature of the crystal str...

The simple organic crystal formamidinium iodide (FAI) appeared to be a novel semiconducting material in a wide temperature range. The electric properties of FAI and the role of formamidinium cation (FA⁺) in the molecular mechanism of the solid-to-solid phase transitions (at 345 K (III → II) and 388 K (II → I)) were analysed. The creation of the fer...

Bis(piperazine-1,4-diium) decabromodiantimonate(III) dihydrate, (C4H12N2)2[Sb2Br10]·2H2O, (abbreviated as PSB) has been synthesized and characterized by single-crystal X-ray diffraction studies. The obtained results indicate that PSB is isostructural with a recently described chloride analogue, (C4H12N2)2[Sb2Cl10]⋅2H2O (PSC), crystallizing with R2M...

The crystal structures of (2,4,6-CH3PyH)3Sb2Cl9 (TMPCA) and (2,4,6-CH3PyH)3Bi2Cl9 (TMPCB) (Py – pyridine) have been determined at 100 K by the single crystal X-ray diffraction method. TMPCA and TMPCB crystallize in the monoclinic C2/c and triclinic P1 polar space group, respectively. In both cases the asymmetric part is comprised of three nonequiva...

(1)H spin-lattice relaxation experiments have been performed for [NH2(CH3)2]3Sb2Cl9 (tris(dimethylammonium)nonachlorodiantimonate(iii)) in the temperature range of 253-313 K and a broad range of frequencies - from 4 kHz to 40 MHz. From the analysis of quadrupolar relaxation enhancement effects (quadrupolar peaks) associated with (14)N nuclei, two l...

9 ] (ImIB), have been synthesized and characterized in a wide temperature range (100–350 K) by means of X-ray diffraction, dielectric spectroscopy, proton magnetic resonance (1 H NMR), FT-IR spectroscopy and optical observations. They undergo two temperature induced solid–solid structural phase transitions. The first one, quasi-continuous (with tem...

1H nuclear magnetic resonance relaxometry has been applied to reveal information on dynamics and structure of Gu3Bi2I9 ([Gu = C(NH2)3] denotes guanidinium cation). The data have been analyzed in terms of a theory of quadrupolerelaxation enhancement, which has been extended here by including effects associated with quadrupole (14N) spin relaxation c...

Dipyrazolium iodide triiodide, [C3N2H5(+)]2[I(-)·I3(-)], has been synthesized and studied by means of X-ray diffraction, differential scanning calorimetry, dielectric measurements, and UV-Vis spectroscopy. Two reversible, solid-solid phase transitions (Imma (I) ↔ (II) ↔ Pbam (III)) at 254 K and 182/188 K respectively have been revealed. The anionic...

Diisobutylammonium bromide is found to be a unique improper ferroelastic in which the elastic degrees of freedom seem to play the essential role, giving a rise to a domain pattern resembling that of martensitic phase transitions. A weak canted ferroelectricity turns out switchable by an electric field. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinh...

1H spin-lattice field cycling relaxation dispersion experiments in the intermediate phase II of the solid [C3H5N2]6[Bi4Br18] are presented. Two motional processes have been identified from the 1H spin-lattice relaxation dispersion profiles and quantitatively described. It has been concluded that these processes are associated with anisotropic reori...

Some of haloantimonates(III) and halobismuthates(III) are ferroelectric. Bis(imidazolium) pentachloroantimonate(III), (C3N2H5)2SbCl5 (abbreviation: ICA) is the first example of such compounds with a one-dimensional anionic chain which exhibits ferroelectric properties. The relation between the ionic dynamics and network structure and the ferroelect...

The crystal structure of two novel 1,2,4-triazolium analogues: [C2N3N4](2)[BiCl5] (TBC) and [NH4][C2N3H4](3)[BiCl6][Cl] (TCBA), isolated from one system, has been determined. The structure of TCBA is built up from cationic substructures consisting of 1,2,4-triazolium and ammonium cations, [Cl](-) and discrete [BiCl6](3-) octahedral anions. The two-...

The reaction of imidazole with hydroiodic acid leads to three products crystallizing as ionic salts; [C3N2H5+][I−], [C3N2H5+]2[I42−] and [C3N2H3I2+][I−]. All the analogs were characterized by single-crystal X-ray diffraction, while the first two were additionally studied by calorimetric, dilatometric, dielectric and proton magnetic resonance method...

[4-NH2C5H4NH][C4H3O4][C4H4O4] (abbreviated as APM) and its N,O-deuterated analogue have been synthesized. The single-crystal X-ray diffraction studies for N,O-deuterated analogue are reported. The Kurtz and Perry powder SHG technique confirms the second order nonlinear optical properties of APM. The structural phase transition of APM occurring at 3...

Proton spin-lattice relaxation times T1 at 24.7MHz and 15MHz and second moment of NMR line have been applied to study molecular dynamics of a novel ferroelectric (NH4)2H2P2O6 (Tc=178K) in the temperature range 10-290K. Low-temperature T1 behaviour below Tc is interpreted in terms of Haupt's theory and Schrödinger correlation time of tunnelling jump...

The structure of [C2H5NH(CH3)2+]3[BiCl6−] (abbreviated as DCB) was determined by a single-crystal X-ray diffraction at 115 K. The compound adopts tetragonal symmetry with the space group I41/acd; a = 23.35 Å, c = 17.60 Å, V = 9598 Å3 and Z = 16. The crystal structure of DCB is built up of isolated [BiCl6]3− units and N,N-dimethylethylammonium count...

A quite uncommon type of heat anomaly has been disclosed by calorimetric experiments in ferroelectric crystal (C3N2H5)5Bi2Br11(C3N2H5)5Bi2Br11 close to the paraelectric-ferroelectric transition. Thermal parameters (such as the excess enthalpy (ΔΔH) and the excess entropy (ΔΔS)) of the continuous ferroelectric phase transition at ca. 155 K have been...

Calculations of the molecular structure and normal vibration frequencies have been performed using ADF (Amsterdam Density Functional) program package for initial structural data of 1-aminopyridinium iodide, (1-NH2C5H5N)+I�, low temperature phase (110 K). Cambridge Structural Database survey has been carried out in order to explore hydrogen bond pat...

The hydrostatic pressure effect on the dielectric properties of (NH4)2H2P2O6 ferroelectric crystal was studied for pressures from 0.1 MPa to 360 MPa and for temperatures from 100 to 190 K. The pressure–temperature phase diagram obtained is linear with increasing pressure. The paraelectric–ferroelectric phase transition temperature decreases with in...

1-Aminopyridinium iodide (API) undergoes a reversible first-order phase transition (PT) II → I at 384 K. The single-crystal X-ray diffraction studies have been carried out at 110, 280 and 401 K. The compound crystallizes in the monoclinic space group P21/c (phase II) and exhibits ferroelastic properties. High temperature paraelastic phase (I) is de...

Dielectric properties and phase transitions of the piperazinium tetrafluoroborate ([NH2(CH2)4NH][BF4][NH2(CH2)4NH][BF4], abbreviated as PFB) crystal are related to the one-dimensional arrangement of the cations linked by the bistable NH+⋯NNH+⋯N hydrogen bonds and molecular motions of the [BF4]−[BF4]− units. The crystal structure of [NH2(CH2)4NH][BF...

Thiazolium cation Sb(III) and Bi(III) X-ray diffraction Dielectric relaxation 1 H NMR a b s t r a c t Two thiazolium analogs, (C 3 H 4 NS) 6 Sb 4 Br 18 Á2H 2 O (TBA) and (C 3 H 4 NS) 6 Bi 4 Br 18 Á2H 2 O (TBB), have been syn-thesized and structurally characterized. The compounds appeared to be isomorphous and crystallize in the triclinic symmetry,...

The first precise measurements of specific heat changes have been performed for a novel ferroelectric material, (NH4)2H2P2O6 by means of an ac calorimeter. The paraelectric–ferroelectric phase transition at about 177.5K of second order type is revealed and described by the Landau model using specific heat and linear birefringence data. Thermal para...

NMR relaxometry has gained popularity in recent years, due to advances in experimental methodology and theory. We present an overview of applications of NMR relaxometry (with special focus on Field Cycling studies) to solid state, including a variety of systems ranging from simple crystals to proteins. Mechanisms and principles of the relaxation ef...

Electric permittivity, reaching ca. 4800 units at Tc, of the first haloantimonate(III) ferroelectric with R2MX5 composition characterized by unprecedented SbCl5 chains of cis-connected octahedra results from the mixed ‘order–disorder’ and ‘displacive’ mechanism of the phase transition.

[4-NH2C5H4NH][C4H3O4][C4H4O4](APM) complex with rare stoichiometric ratio 1:2 has been synthesized and characterized by a single-crystal X-ray diffraction and powder X-ray diffraction in a wide temperature range (from 100 K up to 338 K), calorimetry and dielectric spectroscopy. The APM undergoes structural phase transition at 307/312 K (cooling/hea...

The single crystals of the following 4-dimethylaminopyridinium chloroantimonates(III) and chlorobismuthates(III) have been grown by the solvent evaporation method: (C(7)H(11)N(2))SbCl(4), (C(7)H(11)N(2))BiCl(4) and (C(7)H(11)N(2))(4)Bi(2)Cl(10). The one-dimensional (1D) structures for (C(7)H(11)N(2))SbCl(4) or (C(7)H(11)N(2))BiCl(4) and the zero-di...

Molecular dynamics of a polycrystalline sample of (CH(3)NH(3))(5)Bi(2)Br(11) (MAPBB) is studied on the basis of the proton T(1) (55.2 MHz) relaxation time and the proton second moment of NMR line. The T(1) (55.2 MHz) was measured for temperatures from 20K to 330 K, while the second moment M(2) for those from 40K to 330 K. The proton spin pairs of t...

A different organic-inorganic crystal—[2,4,6-trimethylpyridinium][BF4]—of nonlinear optical properties at room temperature was synthesized and characterized. The compound is built up of the organic [2,4,6-trimethylpyridinium] cations incorporated into inorganic, tetrahedral BF4 anions. It crystallizes at room temperature in the polar space group Pm...

The effect of internal bias field on the field - induced movement of the domain walls in (CH 3NH 3)5Bi 2Br 11 crystals has been investigated using liquid crystal decoration technique (NLC). The measurements were carried out in dc - electric field and alternate square pulses of electric fields. Comparison was made of the nucleation process in (CH 3N...

The first precise measurements of specific heat changes have been performed for a ferroelectric crystal (C3N2H5)5Sb2Br11 by means of an ac calorimeter. The calorimetric measurements disclosed a quite uncommon type of heat anomaly close to the paraelectric–ferroelectric transition. The ferroelectric phase transition at about 145 K has been character...

The ferroelastic-ferroelectric phase transition and the ferroelastic domain structure have been studied for DMACA crystal. The paraelastic point group 3m is proposed. The para-electric-intermediate-ferroelectric phase transitions have been investigated for TMACA crystal using the linear birefringence measurements. The critical index value and the p...

Study of far-infrared (5-400 cm−1) reflectivity spectra of two isomorphous (Pca21) ferroelectric compounds: (CH3NH3)5Bi2Cl11 and (CH3NH3)5Bi2Cl11 has been performed in the temperature range 90-330 K. The ferroelectric type transitions occurring at 307 K and 312 K in the mentioned compounds, respectively, manifest itself as continuous, order-disorde...

A novel nonlinear optical crystal has been synthesized and characterized by a single-crystal X-ray diffraction, calorimetric, dilatometric and dielectric measurements. Above 200 K the crystal structure is polar, with symmetry R3. It consists of a highly disordered imidazolium cations and discrete Br- anions. The compound reveals a first order phase...

Tris(imidazolium) hexabromoantimonate(III) hydrate, (C{sub 3}N{sub 2}H{sub 5}){sub 3}SbBr{sub 6}.H{sub 2}O, (abbreviated as TIBA) has been synthesized and characterized by X-ray (at 295, 225, 160, and 110 K), differential scanning calorimetry, dilatometry, and dielectric spectroscopy. At room temperature (phase I), the structure consists of discret...

Temperature dependences of proton spin–lattice relaxation times for two guanidinium compounds, [C(NH2)3]3Sb2Br9 and [C(NH2)3]3Sb2Cl9, are reanalyzed by taking into account all relaxation pathways available for protons. It turns out that the experimental data reflect two relaxation processes, which have to be described separately. The bi-exponential...

The novel inorganic–organic hybrid material, allylammonium hexabromoantimonate(III), (C3H5NH3)3SbBr6, has been synthesized and its structure has been determined by means of the single-crystal X-ray diffraction studies at five temperatures (273, 248, 220, 170 and 100K). At room temperature the compound crystallizes in the monoclinic space group, C2/...

Abstract. Single crystals of the organic2inorganic arsenate(III):[(CH3)2NH2]3[As2Cl9] and [(CH3)2NH2][AsOCl2] have been grown from aqueous hydrochloric acid solution. The crystals [(CH3)2NH2]3[As2Cl9] have been investigated by X2ray diffraction (at 253 K), different ial scanning calorimetry (DSC), thermogravimetric analysis (TGA), dilatometric and...

A novel compound, [4-NH2PyH]8[Bi2Cl11][Bi2Cl9(H2O)2] (abbreviated as 4APCB), was synthesized and structurally characterized at 100, 150 and 301 K. 4APCB crystallizes in a triclinic centrosymmetric space group, P1¯. The anionic framework is built up of two types of inorganic fragments, namely [Bi2Cl11]5-[Bi2Cl11]5- and [Bi2Cl9(H2O)2]3-[Bi2Cl9(H2O)2]...

[(CH3)3PH]3[Sb2Cl9] (abbreviated as TMPCA) was found to undergo numerous reversible structural phase transitions studied by dilatometric and dielectric methods: I↔II at 375/372 (heating/cooling), II↔III at 272/272, III↔IV at 223/216 and IV↔V at 212/206K. Debay-like dispersion of the electric permittivity in the kilohertz frequency region over the p...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

[(CH{sub 3}){sub 3}C{sub 5}H{sub 2}NH][ClO{sub 4}] has been synthesized and characterized by X-ray (at 344, 245, 180 and 115 K), calorimetric, dilatometric, dielectric and pyroelectric measurements. At room temperature the crystal structure is polar, space group Pmn2{sub 1}. It consists of discrete disordered [ClO{sub 4}]{sup -} anions and ordered...

[C{sub 3}N{sub 2}H{sub 5}]{sub 6}[Bi{sub 4}Br{sub 18}] has been synthesized and characterized by the X-ray (at 293 and 110 K), calorimetric, dilatometric and dielectric measurements. At room temperature it crystallizes in the monoclinic space group, C2/m. A crystal structure consists of disordered imidazolium cations and ordered discrete tetramers...

Infrared spectra of the powdered (C3N2H5)5Bi2Cl11, (C3N2H5)5Bi2Br11and (C3N2H5)5Sb2Br11 crystals in the region of internal vibrations of the imidazolium cations (3600 and 400 cm−1) at the temperature intervals of 10–300 K, covering paraelectric–ferroelectric phase transitions, are presented and discussed in this paper. The research shows that the v...

(C5H5NH)3BiCl6 crystallizes at room temperature in the triclinic space group P. The crystal is built up of the separated octahedral anions and pyridinium cations. Differential scanning calorimetry (DSC) and dilatometric measurements disclose structural phase transition of first-order type at 265/302 K (cooling/heating). The dielectric investigation...

The crystal structure of [C4H10NO][BF4] is determined in the phase I at 160, 180, 240 and 290 K. At room temperature the compound crystallizes in the orthorhombic space group: Pnam. The structure is composed of the morpholinium cations, [C4H10NO]+, which form one-dimensional hydrogen bonded chains, and [BF4]− anions. [C4H10NO][BF4] undergoes two st...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The proton dynamics and the imidazolium cation molecular motions of (C3N2H5)5Bi2Cl11 have been studied by means of CW 1H NMR analysis in a wide range of temperatures. The results have been correlated with the ones obtained by means of the electric conductivity measurements. It was found that conductivity rapidly increases at the temperature of 227...

Low frequency dielectric dispersion studies have been carried out for the ferroelectric pentakis(imidazolium) undecabromodibismuthate(III)— (C3N2H5)5Bi2Br11—single crystal in the paraelectric phase in the radio-frequency region (100 Hz–1 MHz). The dielectric dispersion, observed for an electric field along the a-axis (P 21/n space group), is chara...

The low temperature inelastic incoherent neutron scattering spectra of pentakis (imidazolium) undecachlorodibismuthate (III) [(C3N2H5)5Bi2Cl11] were discussed versus different models of reference structures obtained by quantum chemical calculations in the energy transfer range up to 1200 cm−1. The second moment of 1H NMR line and spin–lattice relax...

Two polymorphic forms of pyrazolium bromoantimonates(III) – [C3N2H5]6Sb4Br18·2H2O: α modification – tetragonal form and β modification – triclinic form, have been synthesized and structurally characterized at 100 K. The α-polymorph consists of a unique three-dimensional (3D) anionic substructure built up of cyclic tetramers and discrete chains link...

The group of mixed crystals of general formula: [4-APyH][SbCl4(1−x) Br4x] with x ranging from 0 to 1 was studied by means of differential scanning calorimetry, dilatometry and dielectric spectroscopy. The ferroelectric properties are preserved for mixed crystals with replacement fraction, x, less than 0.30. Moreover, such a substitution of the chlo...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The crystal structures of [C 3 H 4 NS] 6 [M 4 Cl 18 ]Á2H 2 O (M = Sb, Bi) consist of three nonequivalent thiazolium cations and discrete centrosymmetric anions [M 4 Cl 18 ] 6À . The title compounds appear to be isomorphous and crystallize in the triclinic space group, P 1 (at 100 K). One of three thiazolium cations was found to be disordered (two-s...

A ferroelectric crystal [C3N2H5]5[Bi2Br11] has been synthesized and structurally characterized at 170 and 100 K. The crystal structure consists of discrete corner-sharing bioctahedra [Bi2Br11]5− and highly disordered imidazolium cations. The room temperature crystal structure has been determined as monoclinic, space group, P 21/n with: a = 9.257(2)...

Single crystals of pentakis (imidazolium) undecachlorodibismuthate (III); (C(3)N(2)H(5))(5)Bi(2)Cl(11), have been studied by the dielectric method at ambient and hydrostatic pressures. At ambient pressure the crystals undergo a ferroelectric phase transition of order-disorder type at 166 K. The character of the dielectric permittivity anomalies is...

Two novel guanidinium iodoantimonate(III) and iodobismuthate(III) crystals, [C(NH2)3]3[Sb2I9] and [C(NH2)3]3[Bi2I9], have been synthesized and their structures have been determined by means of single-crystal x-ray diffraction studies at three temperatures (293, 348 and 362 K). Both compounds appeared to be isomorphous in corresponding phases. The c...

A ferroelectric crystal (C3N2H5)5Sb2Br11 has been synthesized. The single crystal X-ray diffraction studies (at 300, 155, 138 and 121 K) show that it is built up of discrete corner-sharing bioctahedra Sb2 Br115 - and highly disordered imidazolium cations. The room temperature crystal structure has been determined as monoclinic, space group, P 21 /...

A combination of infrared and inelastic incoherent neutron scattering spectroscopies with the density functional theory and semi-empirical calculations was applied to propose an assignment of the vibrational spectra of 4-aminopyridine chloroantimonate(IV).

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The di(n-pentylammonium) pentabromoantimonate(III) compound has been synthesized and studied by means of a single-crystal X-ray diffraction, differential scanning calorimetry, thermal expansion, dielectric and IR techniques. Two solid–solid phase transitions of first order: at 416/388K and 225/224K (heating/cooling) have been revealed. The crystal...

The dielectric properties and conductivity of the (C3H5N2)5Bi2Cl11 crystals (abbreviated as ICB) in the paraelectric–ferroelastic phase have been studied by impedance spectroscopy as a function of temperature. The low frequency anomaly of the electric capacitance observed in ICB crystal has been found to be qualitatively similar to that observed at...

Crystal structures of [4-NH 2 C 5 H 4 NH][GaCl 4 ] ([4-NH 2 PyH][GaCl 4 ]) have been determined at 80 and 120 K by single crystal X-ray diffraction (trigonal space groups R3 and R3m, respectively). DSC studies indicate a presence of one reversible phase transition close to the second order at 110 K with DS % 1 J mol À1 K À1 . Infrared spectra of po...

The structure of [C3N2H5]4[Bi2Br10]·2H2O, (PBB) was determined by single crystal X-ray diffraction at 100K. It crystallizes in the monoclinic space group C2/m, with a=12.992(4)Å, b=16.326(5)Å, c=8.255(3)Å, β=108.56°(3), V=1659.9(9)Å3 and Z=2. The structure consists of discrete binuclear [Bi2Br10]4− anions, ordered pyrazolium cations and water molec...

The crystal structure of [C3H5N2]6Bi4Cl18 has been determined at 293K by single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group, C2/m. The structure is composed of the discrete Bi4Cl186- anions and three kinds of the imidazolium cations. The cations appeared to be disordered. The infrared spectra of [C3H5N2]6Bi4Cl...

Dielectric dispersion studies have been carried out on the pentakis( imidazolium) undecabromodiantimonate(III), (C3N2H5) 5Sb2Br11, single crystal in the audio-frequency region. It is found that low-frequency dielectric dispersion, observed for the field along the alpha-axis of the monoclinic symmetry (P2(1)/n), reveals a polydispersive nature near...

Dielectric dispersion studies have been carried out on the pentakis(imidazolium) undecabromodiantimonate(III), (C3N2H5)5Sb2Br11, single crystal in the audio-frequency region. It is found that low-frequency dielectric dispersion, observed for the field along the a-axis of the monoclinic symmetry (P 21/n), reveals a polydispersive nature near the par...

Infrared spectra of powdered 4-aminopyridinium tetrachloroantimonate(III) [4-NH2C5H4NH][SbCl4] (abbreviation: 4-APCA) in the region of the internal vibrations of the 4-aminopyridinium cation (3600 and 400cm−1) and in the temperature interval 10–300K covering three structural phase transitions are presented and discussed. The results confirm the ord...

The effect of pressure on the dielectric properties of [NH2(CH3)2]3Sb2Cl9 crystal was analyzed for a few values of hydrostatic pressure within the range from 0.1 MPa to 300 MPa and for temperatures from the range of 220-350 K. The measuring frequency was 1 kHz. The pressure-temperature phase diagram obtained was nonlinear. The temperature dielectri...

The structure of [C 3 N 2 H 5 ] 4 [Bi 2 Br 10 ]$2H 2 O, (PBB) was determined by single crystal X-ray diffraction at 100 K. It crystallizes in the mono-clinic space group C2/m, with a ¼ 12.992(4) Å , b ¼ 16.326(5) Å , c ¼ 8.255(3) Å , b ¼ 108.56 (3), V ¼ 1659.9(9) Å 3 and Z ¼ 2. The structure consists of discrete binuclear [Bi 2 Br 10 ] 4À anions, o...

Thermal (specific heat) and optical (linear birefringence) studies were performed for a new ferroelectric crystal (C3N2H5)5Bi2Cl11. Two phase transitions were confirmed and described. The first-order paraelastic–ferroelastic phase transition at 360 K was studied with a polarizing microscope. The continuous second-order phase transition at 165 K to...

[C3H5N2]6[Bi4Cl18] crystallizes at room temperature in the monoclinic space group; C2/m. It undergoes two solid–solid phase transitions of first-order type at 221/218 K (heating–cooling) from phase I to II and at 195/145 K from phase II to III. The dielectric relaxation process was found to appear in a kilohertz frequency region over the phase III...

Crystal structure of 4-cyanopyridynium perchlorate monohydrate ([(4-CNC5H4NH)][ClO4]·H2O) has been determined at 293 and 240 K as orthorhombic space group, Pnma and monoclinic space group, P21/c, respectively, by means of single crystal X-ray diffraction. At room temperature the perchlorate anion reveals significant disorder, which is realized by t...

Tris(imidazolium) nonabromodiantimonate(III), [C{sub 3}H{sub 5}N{sub 2}]{sub 3}[Sb{sub 2}Br{sub 9}], is trimorphic. Its crystal structure has been determined at 100K (form I) and 293K (form II) by X-ray single crystal diffraction in, respectively, the monoclinic space groups, P2{sub 1}/c (form I) and P2{sub 1}/n (form II). In both structures, the a...

Tris(imidazolium) nonabromodiantimonate(III), ½C 3 H 5 N 2 Š 3 ½Sb 2 Br 9 Š, is trimorphic. Its crystal structure has been determined at 100 K (form I) and 293 K (form II) by X-ray single crystal diffraction in, respectively, the monoclinic space groups, P2 1 =c (form I) and P2 1 =n (form II). In both structures, the anionic sublattice forms corrug...

The crystal structure of [4-CH3C5H4NH][SbBr4] is determined at 297 K. The compound crystallizes in the monoclinic space group: P21/c. The structure consists of SbBr4− ions which form infinite chains through the crystal via halogen linkages. The anions are connected with the 4-methylpyridinium via weak NH⋯X hydrogen bonds. The phase situation was st...

The crystal structure of dipropylammonium hexachloroantimonate(V), [N(C3H7)2H2][SbCl6] (DPACA) has been determined by means of X-ray diffraction at 290 K. The compound crystallizes in the monoclinic space group: P21/n. The crystal undergoes three structural phase transitions: two first-order type at 388/376 K (heating-cooling) from phase (I) to (II...

[ n-C 4H 9NH 3] 2[BiBr 5] exhibits five solid-solid structural phase transitions; at 309 (1st order), 291 (1st), 240 (1st), 219 (close to 2nd) and at 166 K (1st). The phase transitions at 291 and 240 K are accompanied by distinct dielectric anomalies. The dielectric relaxation process was found to appear over the phases (III) and (I). The infrared...

The crystal structure of 4-aminopyridinium tetrachlorobismuthate(III), [4-NH2PyH ][BiCl4 ], has been determined at 100 and 260 K by the x-ray diffraction method as monoclinic space group, P 21/c and C 2/c, respectively. Differential scanning calorimetry and dilatometry reveal one perfectly reversible discontinuous phase transition at 254/255 K (coo...

The polarization switching in methylammonium chlorobismuthate, (CH3NH3)5Bi2Cl11, single crystal was investigated by optical observations of the domain structure and switching current registration. It is shown that defects introduced during crystal growth influence the polarization switching kinetics. For the analysis of switching current data the s...

The crystal structure of 2-cyanopyridinium perchlorate, [2-CNPyH][ClO4], has been determined at 100 (phase II) and 293 K (phase I). It is monoclinic P 21 at 100 K and orthorhombic P 212121 at 293 K. The dynamic properties of the crystal were studied by differential scanning calorimetry, dilatometry, pyroelectric, dielectric, proton (1H NMR), chlori...