三苯基锡4－吡啶甲酸酯的合成、性质和晶体结构

用三苯基氯化锡与4-吡啶甲酸钠反应，合成了三苯基锡4-吡啶甲酸酯，并进行 了红外光谱、核磁共振氢谱及质谱表征。X射线单晶衍射表明，化合物属单斜晶系 ，空间群P21，晶胞参数：a=1.6629（3）nm，b=104987(4)nm，c=2.4318(7)nm，β =90.040（5）°，Z=8,Dc=1.1529g/cm^3，R1=0.0543，wR2=0.1086。化合物的晶体 是由两个结构相似但键长和键角不同的独立分子所组成，且每个分子含有两种化学 环境不同的锡原子。它们通过4-吡啶甲酸配体的氮原子桥联，形成五配位三角双锥 构型的一维无限链聚合物。     

三苯基锡2－噻吩甲酸酯的合成、性质和晶体结构

用三苯基氯化锡与2-噻吩甲酸钠反应，合成了三苯基锡2-噻吩甲酸酯，并进行 了红外光谱、核磁共振氢谱及质谱表征。X射线单晶衍射表明，化合物属单斜晶系 ，空间群P21/n，晶胞参数：a=1.3429(7)nm，b=1.11773(6)nm，c=1.4241(8)nmβ =116.519(6)°，V=2.0146(18)nm^3,Z=4，Dc=1.573g/cm^3，R1=0.0391，Wr2=0. 0943。该化合物的晶体是由孤立的分子所组成，四配位的锡原子呈畸变的四面体构 型，配体噻吩环上的硫原子和锡原子之间存在弱的配位作用。     

Synthesis and crystal structure of triphenyltin and lead complexes with organic peroxides

Crystalline triphenyltin cumyl and tert-butyl peroxides (Ph₃SnOOCMe₂Ph and Ph₃SnOOBu^t, respectively) and triphenyllead cumyl peroxide (Ph₃PbOOCMe₂Ph) were synthesized and characterized by single crystal and powder X-ray diffraction, NMR, FTIR and Raman spectroscopies, TG and DSC analysis. The formation of triphenyltin tert-butyl peroxide in benzene in the presence of a base was proved by ¹¹⁹Sn, ¹³C and ¹H NMR spectroscopy. To the best of our knowledge, the obtained complexes are the first structurally characterized coordination compounds of tin and lead with organic peroxides.     

The crystal and molecular structure of the cycloadduct from an activated carbodiimide and methyl isothiocyanate

The crystal and molecular structures of the cycloadduct from isopropyl[α-(dimethylthio-carbamoyl)isopropyl]carbodiimide and methyl isothiocyanate were determined by single-crystal X-ray methods. The product was established to be 2-(1-isopropyl-3,5-dimethyl-4,6-dithioxo-hexahydro-1,3,5-triazine-2-ylidenamino)-N,N-dimethylthioisoburyramide, in which contrary to expectations based on hybridisation the heterocyclic ring adopts a boat conformation.     

三维骨架结构有机锡化合物－－1，5－戊二酸双（三苯基锡）酯的合成、谱学表征和晶体结构

用三苯基氯化锡与1，5－戊二酸二钠以2：1摩尔比反应，合成了1，5－戊二酸 双（三苯基锡）酯，并进行了红外光谱、核磁共振氢谱及质谱表征。X射线单晶衍 射表明，该化合物属正交晶系，空间群C222（1），晶胞参数：a=1.5075(5)nm， b=4.8021(17)nm,c=2.8944(9)nm,α＝90°,β=90°，γ＝90°，V＝20.953(12) nm^3，Z=8,Dc=1.316g/cm^3，μ＝1.226mm^-1,F(000)=8280,R1=0.0546,wR2=0. 1182。晶体结构中存在5种化学环境不同的三角双锥构型的锡原子，由于配体中两 个羧基在不同方向的交联作用，使化合物呈现三维骨架结构，并且在骨架结构中存 在沿a轴和c轴方向伸展的规则的大环直孔道。     

Preparation and disordered crystal structure of (18-crown-6)ammonium isothiocyanate hemihydrate

A crystalline complex salt, (18-crown-6)ammonium isothiocyanate hemihydrate [NH ₄ ⁺ (18C6)]·SCN^?·0.5H₂O, was prepared and studied by single-crystal X-ray diffraction. The crystal structure of this salt is highly disordered: Almost all the constituents (except the water molecule) are disordered over two different orientations: major and less occupied or weakly occupied. The geometric parameters (bond lengths, bond angles, etc.) of the molecular and ionic constituents of the salt were determined with reasonable accuracy, and the crystal packing was elucidated. The sale forms in the crystal a complex tetrahedral supramolecular hydrogen-bonded structure consisting of one water molecule, two complex cations [NH ₄ ⁺ (18C6)], and two SCN^? anions.     

IR,PMR and Mössbauer studies on the complexes of triphenyltin chloride and triphenyltin isothiocyanate with a series of N-alkylsalicylideneimines

Eleven new complexes of the type Ph₃SnX: o-HOC₆H₄CHNR (X = Cl, NCS; R = CH₃, t-Bu, PhCH₂, n-C₆H₁₃, c-C₆H₁₁, HOCH₂CH₂) have been synthesized by the reactions of triphenyltin chloride or isothiocyanate with the N-alkylsalicylideneimines. The complexes are non-electrolytes in nitrobenzene. IR, PMR and Mössbauer spectroscopic studies indicate that the ligands are behaving as monodentates via the phenolic oxygen atoms, and that the complexes all have trigonal bipyramidal geometry with the phenyl groups occupying the equatorial positions.     

The structure of tetraarylantimony halides and tetraphenylantimony isothiocyanate

X-ray diffraction analysis is used to study tetraphenylantimony fluoride (I), tetra-p-tolylantimony (II), and tetraphenylantimony isothiocyanate (III), where Sb atom has a distorted trigonal-bipyramidal coordination. The Sb-C bond lengths in I–III lie a range of 2.102(1)–2.183(1) Å; the Sb-F, Sb-Cl, and Sb-N distances are equal to 2.0530(8) Å, 2.7319(7) Å, and 2.507(2)Å, respectively, in I, II, and III.Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 2, 2005, pp. 117–124.Original Russian Text Copyright © 2005 by Sharutin, Sharutina, Pakusina, Smirnova, Pushilin.     

Vibrational spectra and structure of triphenyltin halides

The solid state IR and Raman spectra of SnPh₃Br do not show any band at 338 cm⁻¹, and there is not C_3ν point group inversion between ν_as SnC₃ and ν_s SnC₃ for SnPh₃X (X  Cl, Br). The presence or absence of a band around 338 cm⁻¹ in the IR spectra of triphenyltin compounds cannot be used to distinguish between pyramidal and planar SnPh₃ groups.     

The crystal structure of L-arginine

We report the crystal structure of L-arginine, one of the last remaining natural amino acids for which the crystal structure has never been determined; structure determination was carried out directly from powder X-ray diffraction (XRD) data, exploiting the direct-space genetic algorithm technique for structure solution followed by Rietveld refinement.     

The crystal structure of polyacrylonitrile

Polyacrylonitrile (PAN) has been prepared by a free-radical mechanism using azobisisobutyronitrile as the initiator. Fibres were produced by extruding a solution of this polymer into dilute sodium thiocyanate. Wide-angle X-ray analysis showed that the resulting fibres exhibited a moderate degree of crystalline order. An orthorhombic unit-cell has been proposed to account for the observed reflections, the cell constants are: $\text{a = 21·48 ± 0·02}\text{A}\text{?}\text{; b = 11·55 ± 0·03}\text{A}\text{?}\text{; c = 7·096 ± 0·003}\text{A}\text{?}$. A helical structure has been proposed for PAN with four monomer units per crystallographic repeat. The probability of a syndiotactic configuration has been suggested to account for the meridional reflections; the calculated density of the proposed cell (1·199 g cm^?3) was found to agree very well with values quoted in the literature.