Thermal decomposition of manganese(II)bis(oxalato)nickelate(II)tetrahydrate

Summary A mixed metal oxalate, manganese(II)bis(oxalato)nickelate(II)tetrahydrate, has been synthesized and characterized by elemental analysis, IR spectral and X-ray powder diffraction (XRD) studies. Thermal decomposition studies (TG, DTG and DTA) in air showed that the compound decomposed mainly to Mn₂O₃, MnO₂ and NiO at ca.1000°C, via. the formation of several intermediates. DSC study in nitrogen upto 500°C showed the endothermic decomposition. The tentative mechanism for the thermal decomposition in air is proposed.     

The synthesis and liquid crystalline behaviour of alkoxy-substituted derivatives of 1,4-bis(phenylethynyl)benzene

Despite the prevalence of organised 1,4-bis(phenylethynyl)benzene derivatives in molecular electronics, the interest in the photophysics of these systems and the common occurrence of phenylethynyl moeties in molecules that exhibit liquid crystalline phases, the phase behaviour of simple alkoxy-substituted 1,4-bis(phenylethynyl)benzene derivatives has not yet been described. Two series of 1,4-bis(phenylethynyl)benzene derivatives, i.e. 1-[(4'-alkoxy)phenylethynyl]-4-(phenylethynyl)benzenes (5a-5f) and methyl 4-[(4'-alkoxy)phenylethynyl-4'-(phenylethynyl)] benzoates (18a-18f) [alkoxy = n-C₄H₉ (a), n-C₆H₁₃ (b), n-C₉H₁₉ (c), n-C₁₂H₂₅ (d), n-C₁₄H₂₉ (e), n-C₁₆H₃₃ (f)] have been prepared and characterised. Both series have good chemical stability at temperatures up to 210°C, the derivatives featuring the methyl ester head-group (18a-18f) offering rather higher melting points and generally stabilising a more diverse range of mesophases at higher temperatures than those found for the simpler compounds (5a-5f). Smectic phases are stabilised by the longer alkoxy substituents, whereas for short and intermediate chain lengths of the simpler system (5a-5c) nematic phases dominate. Diffraction analysis was used to identify the SmB_hex phase in (5d-5f) that is stable within a temperature range of approximately 120-140°C. The relationships between the organisation of molecules within these moderate temperature liquid crystalline phases and other self-organised states (e.g. Langmuir-Blodgett films) remain to be explored.     

Synthesis and Properties of a Heteronuclear Ag（Ⅰ）/Ni（Ⅱ） Complex

Introduction Itiswell knownthatcyanogroupsincyanometa latessuchas[Ag(CN)2]-unitscanbeusedasbridg ingligandsandapolymericstructurecanbeformed throughsilver silver(argentophilic)interactions.This propertyhasbeenexploredintheconstructionofmany oligomericandp…     

Crystal growth,spectral characterization and structural studies of a luminescent coordination polymer of calcium(II) complex of benzilic acid

Single crystals of a new calcium(II) complex of benzilic acid, [Ca(C₁₄H₁₁O₃)₂(C₁₄H₁₂O₃)₂] have been successfully grown by gel diffusion technique at room temperature. Single crystal X-ray diffraction study reveals that the compound belongs to orthorhombic system with space group Fddd. The adjacent CaO₈ units are linked via O–H–O interaction to form one dimensional polymeric chains. The extensive hydrogen bonding interactions lead to a supramolecular structure. The grown crystals were further characterized by elemental analysis, FT-IR, UV–Visible, thermogravimetric, powder X-ray diffraction and solid state photoluminescence studies.     

Thermal investigation of bis(methoxy-β-diketonates) of copper(II) — novel CVD precursors of copper films. Crystal structure of bis(2,2,6,8-tetramethyl-6-methoxynonan-3,5-dionato)copper(II)

Seven copper(II) bis-chelates derived from novel sterically hindered ligands — methoxy-β-diketones     

Synthesis, structural investigation and thermal stability of aqua magnesium(II) phthalocyanine bis(diethylamine) solvate

Aqua magnesium phthalocyanine bis(diethylamine) complex was obtained in the crystalline form and its crystal structure was determined by single-crystal X-ray diffraction. The Mg atom is 4 + 1 coordinated by four N isoindole atoms and one O atom. The MgPc moiety is non-planar, the Mg(II) is deviated by 0.492(2) Å from the N₄-isoindole plane towards the oxygen atom of water molecule. The arrangement of MgPc(H₂O) and diethylamine molecules is determined by O–HN hydrogen bonds and π–π interactions. The complex is stable up to 140 °C. At this temperature the complex loses diethylamine molecules and next at 200 °C loses the water molecule and finally converts into β-MgPc.     

Synthesis and oxidation of bis(triphenylgermyl)zinc

Bis(triphenylgermyl)zinc (Ph₃Ge)₂Zn (1), prepared by the reaction of diethylzinc (Et₂Zn) with two molar amounts of triphenylgermane (Ph₃GeH), was easily reacted by a small amount of oxygen to give tetrameric oxide (Ph₃GeZnO)₄ (2). Four zinc and four oxygen atoms in 2 are arranged such that a cube is formed as determined by X-ray diffraction analysis. Further oxidation of 2 led to the formation of digermoxane, (Ph₃Ge)₂O as a final product.     

Synthesis,Spectroscopic Properties and Crystal Structure of 3,3＇-（Anthracene-9,10-diyl）bis（1-phenylpropan-1-one）

The compound 3,3'-(anthracene-9,10-diyl)bis(1-phenylpropan-1-one)(C32H26O2,Mr=442.55) has been synthesized by the reaction of 2,2'-(anthracene-9,10-diylbis(methy-lene))bis(1,3-diphenylpropane-1,3-dione) with CsCO3,and its structure was characterized by 1H NMR and single-crystal X-ray diffraction.The crystal of the title compound belongs to monoclinic,space group P21/c with a=9.154(3),b=5.2777(16),c=24.897(7) nm,β=107.337(10)°,Z=2 and V=1.1482 nm3.X-ray analysis indicates that an intermolecular hydrogen bond C(8)-H(8A)…O(1),weak C-H···π between H(9A) and the centre of anthracene rings and weak π-π interactions between two anthracene ring planes are observed.     

NMR and fluorescence spectral studies on bisdithiocarbamates of divalent Zn,Cd and their nitrogenous adducts: Single crystal X-ray structure of (1,10-phenanthroline)bis(4-methylpiperazinecarbodithioato) zinc(II)

The current paper describes the synthesis and characterization of the following adducts: [Zn(4-mpzdtc)₂(1,10-phen)] · H₂O (1), [Zn(4-mpzdtc)₂(2,2′-bipy)] (2), [Cd(4-mpzdtc)₂(1,10-phen)] (3), [Cd(4-mpzdtc)₂(2,2′-bipy)] (4), [Zn(padtc)₂(1,10-phen)] (5) and [Cd(padtc)₂(1,10-phen)] (6) (where, 4-mpzdtc = 4-methylpiperazinecarbodithioate anion, padtc = N,N′-(iminodiethylene)bisphthalimide dithiocarbamate anion, 1,10-phen = 1,10-phenanthroline and 2,2′-bipy = 2,2′-bipyridine). All the synthesized complexes were characterized by UV–Vis, IR, NMR, (¹H and ¹³C) and fluorescence spectra. A single crystal X-ray structural analysis was carried out for complex 1. IR spectra of the complexes show the contribution of the thioureide form to the structures. The observed deshielding of the α-protons for 1–6 in the ¹H NMR spectra is attributed to the drift of electrons from the nitrogen of the NR₂ groups, forcing a high electron density towards sulfur via the thioureide π-system. In the ¹³C NMR spectra, the most important thioureide (N¹³CS₂) carbon signals are observed in the region 206–208 ppm. Fluorescence spectra of complexes 5 and 6 show intense fluorescence due to the presence of rigid conjugated systems such as phthalimide and 1,10-phenanthroline. The observed fluorescence maxima for complexes with a MS₄N₂ chromophore in the visible region are assigned to the metal-to-ligand charge transfer (MLCT) processes. Single crystal X-ray structural analysis of 1 showed that the zinc atom is in a distorted octahedral environment with a MS₄N₂ chromophore. VBS equivalent to 1.81 supports the correctness of the determined structure. The piperazine ring in the dithiocarbamate fragment is in the normal chair conformation.     

Comparative evolved gas analytical and structural study on trans-diammine-bis(nitrito)-palladium(II) and platinum(II) by TG/DTA–MS, TG–FTIR, and single crystal X-ray diffraction

Detailed study on identification and thermal decomposition of solid title compounds 1 and 2 crystallized from the used aqueous ammonia solutions of Pd(NH₃)₂(NO₂)₂ and Pt(NH₃)₂(NO₂)₂, has been carried out. Beyond the composition of complexes 1 and 2, their trans square planar configuration have already been recognized by reference IR spectra and powder XRD patterns, nevertheless their exact molecular and crystal structure as of trans-Pd(NH₃)₂(NO₂)₂ (1, Pd-NN) and trans-Pt(NH₃)₂(NO₂)₂ (2, Pt-NN) has been determined by single crystal X-ray diffraction (R = 0.0515 and 0.0341), respectively. Despite their compositional and configuration analogy, they crystallize in different crystal systems and space groups. The crystals of 1 (Pd-NN) are triclinic (space group No. 2, P-1, a = 5.003(1) Å, b = 5.419(1) Å, c = 6.317(1) Å, α = 91.34(2)°, β = 111.890(10)°, γ = 100.380(10)°), while those of 2 (Pt-NN) are monoclinic (space group No. 5, C2, a = 7.4235(16) Å, b = 9.130(2) Å, c = 4.4847(10) Å, β = 99.405(7)°).The pyrolytic processes of 1 and 2 (which might be sensitive to shock and heat) have been followed by simultaneous thermogravimetric and differential thermal analysis (TG/DTA), while the evolved gaseous species have been traced in situ by online coupled TG/DTA–EGA–MS and TG–EGA–FTIR instruments in He and air. Pd and Pt powders, forming as final solid products in single step, are captured and checked by TG and XRD. Whilst the unified evolved gas analyses report evolution of N₂, H₂O, NH₃, N₂O, NO, and NO₂ gases as gaseous product components in the exothermic decomposition of both trans-Pd(NH₃)₂(NO₂)₂ (1) and trans-Pt(NH₃)₂(NO₂)₂ (2) starting from ca. 230 and 220 °C, in sealed crucibles with a pinhole on the top, respectively.     

二(1-环戊烯基茚基)四羰基二钌的合成、晶体结构及热稳定性研究

由6,6-四亚甲基苯并富烯C9H6C(CH2)4与Ru3(CO)12在二甲苯中加热回流,合成了一个钌配合物[((η5-C9H6)C(C4H7))2Ru2(μ-CO)2(CO)2]。通过元素分析、红外、热重、核磁共振进行了表征及研究。用X射线单晶衍射法测定了[((η5-C9H6)C(C4H7))2Ru2(μ-CO)2(CO)2]的结构,结果表明:晶体属于单斜晶系,P21/c空间群,a=0.757 1(13)nm,b=1.577 7(3)nm,c=1.107 3(19)nm,β=90.07(2)°,V=1.322 6(4)nm3,Dc=1.699 g.cm-3,μ=1.179 mm-1,F(000)=676,Z=2,R1=0.030 5,wR2=0.072 4。     

Molecular structure of 2-methylamino-5-[(5-methyl-2-benzoxazolinone-3-yl)methyl]-1,3,4-thiadiazole dihydrophosphate: a combined X-ray crystallographic and ab initio study

Crystal structure of the compound entitled 2-methylamino-5-[(5-methyl-2-benzoxazolinone-3-yl)methyl]-1,3,4-thiadiazole dihydrophosphate is determined using X-ray analysis and compared with the structure obtained from semiempirical and RHF methods at various levels of theory. RHF/6-31G(d) calculations offer the best conformity with X-ray results for bond lengths and bond angles. Moreover, at the result of the comparison of various combinations of basis sets and methods, it appears that there is not much gain in accuracy by using sophisticated methods.     

Crystallographic Studies of Cesium Tetrafluorobromates(III)

This article describes CsBr₂F₇ (1) which has been obtained in the form of colorless single crystals. Shown by the X-ray diffraction on single crystals its Br₂F₇⁻ anion is neither planar nor is its Br−μ-F−Br unit linear, as previously deduced from Raman spectra. Also a regular tetrafluorobromate CsBrF₄ (2) has been obtained in the form of a colorless powder. Compound 2 can also be obtained from compound 1 by evacuation. The crystal structure of CsBrF₄ (2) has been elucidated by the Rietveld refinement on its X-ray powder pattern.     

Syntheses and Crystal Structures of （S）-Methyl 2-（4-R-phenylsulfonamido）-3-（1H-indol-3-yl）propanoate （R = H （1） and Cl （2））

The title compounds （S）-methyl-2-（4-R-phenylsulfonamido）-3-（1H-indol-3- yl）propanoate （R = H （1）, Cl （2）） have been synthesized and their crystal structures also have been determined by X-ray single-crystal diffraction. Compound 1 （C18H18N2O4S） belongs to orthorhombic, space group P212121 with a = 9.6348（14）, b = 11.1517（17）, c = 16.412（3） A, V = 1763.4（5） A^3, Mr = 358.40, Z = 4, De = 1.350 g/cm^3,/t = 0.209 mm^-1, F（000） = 752, R = 0.0348 and wR = 0.0714. Compound 2 （CI8H17ClN2O4S） crystallizes in orthorhombic, space group P212121 with a = 9.3128（14）, b = 10.9655（16）, c = 17.783（3） A, V = 1815.9（5） A^3, Mr = 392.85, Z = 4, De = 1.437 g/cm^3, p = 0.352 mm^-1, F（000） = 816, R = 0.0389 and wR = 0.0845. The absolute structure Flack parameters X of compounds 1 and 2 are -0.03（8） and -0.06（7）, respectively. X-ray analysis reveals that the crystal structures of these two compounds both involve two intermolecular N-H…O hydrogen bond＇s.     

Synthesis,crystal structure,and density functional theory study of a new compound 4-(2-chlorobenzyl)-1-(5-fluoro-2-hydroxy-3-(thiomorpholinomethyl)phenyl [1,2,4]triazolo[4,3-a]quinazolin-5(4H)-one

In this paper, a novel SHP244 derivative 4-(2-chlorobenzyl)-1- (5-fluoro-2-hydroxy-3- [thiomorph-olinomethyl] phenyl)- [1,2,4]triazolo [4,3-a] quinazolin-5(4H)-one was synthesized through five steps. The single crystals were grown in a suitable solvent system (dichloromethane and methanol). Its structure was confirmed by ¹H NMR, ¹³C NMR spectroscopy, ESI-MS, m/z: 534.12[M-H] (MS), FT-IR, and X-ray single crystal diffraction. The crystal structure of the title compound was optimized by density functional theory (DFT) calculation. The crystal structure after X-ray single crystal diffraction was compared with the structure optimized by DFT calculation, and the result shows that the two structures are consistent. In order to explore certain physical and chemical properties, the frontier molecular orbital and molecular electrostatic potential of the title compound were analyzed. In addition, the docking of the title compound to the target protein was studied to understand the docking effect of the compound with the target protein.     

Structurally-driven metal-insulator transition in Ca2Ru1−xCrxO4 (0≤x<0.14): A single crystal X-ray diffraction study

Correlation between structure and transport properties are investigated in high-quality single-crystals of Ca₂Ru_1−xCr_xO₄ with 0<x<0.14 using single crystal X-ray diffraction and by electronic studies. The parent compound was known to exhibit an intriguing first-order structurally driven metal-insulator (MI) transition at 357 K. Upon chromium doping on the ruthenium site, the metal-insulator transition temperature (T_MI) was drastically reduced, and is related to the competition between structural changes that occur upon Cr doping and with decreasing temperature. A strong suppression of structural distortions with increasing Cr substitution was identified. No clear T_MI can be observed when x>13.5% and the system behaves as an insulator. Such a large, sharp metal-insulator transition and tuneable transition temperature may have potential applications in electronic devices.     

Synthesis, spectral and structural characterization of dinuclear rhodium (II) complexes of the anticonvulsant drug valproate with theophylline and caffeine

The dinuclear complex tetra(μ-valproato) dirhodium(II), Rh₂(valp)₄ (1), and its bis-adducts with theophylline, Rh₂(valp)₄(ThH)₂ (4), or caffeine, Rh₂(valp)₄(Caf)₂ (5), have been synthesized and characterized by elemental analysis, IR, UV-Vis, magnetic moment, ¹H and ¹³C NMR spectroscopic techniques. Spectral data for the complexes are consistent with a dinuclear structure as found for rhodium (II) tetracarboxylate adducts. Theophylline and caffeine bases in complexes 4 and 5, respectively, are axially coordinated to rhodium (II) atoms through the sterically hindered N(9) site. This is confirmed by X-ray crystal structure analyses of complexes 4 and 5.     

Coordination diversity in tin compounds with bis(benzoxazole)phenol as a polydentate ligand: Synthesis and crystal structure studies

Abstract

The reaction of 2,6-bis(benzoxazolyl)-4-tert-butylphenol (HL) with [ⁿBu_xSnCl_4?x] (x?=?0, 1) in 1:1 stoichiometry yielded the tin coordination complexes [(HL)SnⁿBu_xCl_4?x] [x?=?0 (1); x?=?1 (2)]. Deprotonation of HL was performed using reagents having groups with high basicity such as ⁿBuLi or [Sn{N(SiMe₃)₂}₂]. These basic reagents prompted the coordination of the ligand in its anionic form, yielding the complexes [(thf)₂Li(L)SnCl₄] (3) and [(L)Sn{N(SiMe₃)₂}] (4), respectively. The molecular structure of HL displayed an intramolecular hydrogen bond OH—N and a planar arrangement of the bis(benzoxazolyl)phenolic system. In the molecular structures of both complexes containing HL an intramolecular hydrogen bond of NH—O type was also present. The coordination of the ligand in either neutral or anionic form is described by a κO,κN chelate mode toward Sn. All complexes displayed bis(benzoxazolyl)phenolic moieties close to planar; the least planar system was observed in 4 that was also studied by DFT methods.     

Synthesis and crystal structure of tris(ethylenediamine)cobalt(III) bis(tetrachloroaurate(III)) chloride

The binary complex salt [Co(N₂C₂H₈)₃][AuCl₄]₂Cl has been synthesized. Its crystal structure has been determined. Crystal data for C₆H₂₄N₆Cl₉AuCo: a = 20.8976(14) Å, b = 14.4773(9) Å, c = 7.9944(5) Å; β = 110.809(2)°; V = 2260.9(3) ų, space group C2/c, Z = 4, d _calc = 2.798 g/cm³. The plane square environment of the gold atom of the complex anion is completed to a tetragonal pyramid by the chlorine atom of the neighboring complex anion (Au…Cl 3.538 Å). The structure is layered. Layers of complex cations and complex anions alternate along the X axis.     

Synthesis and structures of 1,4-bis(chloromethyl)-and 1,4-bis(bromomethyl)cubanes

1,4-Bis(chloromethyl)-and 1,4-bis(bromomethyl)cubanes were synthesized by the reactions of triphenylphosphine with CCl4 and NBS, respectively. The structures of the compounds were studied by X-ray diffraction analysis. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1399–1401, August, 2006.