Solid-state synthesis, structural variants and transformation of three-dimensional sulfides, AGaSnS4 (A=Na, K, Rb, Cs, Tl) and Na1.263Ga1.263Sn0.737S4

New cubic-AGaSnS₄ (A=Na, K, Rb, Cs, Tl) and orthorhombic-NaGaSnS₄ compounds were synthesized by solid-state reactions and characterized by X-ray diffraction and diffuse reflectance spectroscopy. Single crystals of orthorhombic-Na_1.263Ga_1.263Sn_0.737S₄ were obtained in the crystal growth attempts of sodium compound. All six new compounds have orthorhombic AgGaGeS₄ and cubic BaGa₂S₄ structures, as determined from single crystal X-ray structures of Na_1.263Ga_1.263Sn_0.737S₄ and cubic-AGaSnS₄ (A=Na, K, Rb). Orthorhombic-NaGaSnS₄ and known layered-KGaSnS₄ undergo structural transformation to thermodynamically stable cubic form.     

Synthesis and Crystal Structure of 3,3,6,6-Tetramethyl-N-hydroxy-9-ethyl-1,8-dioxo-1,2,3,4,5,6,7,8,9,10-decahydroacridine

1 INTRODUCTION 1,4-Dihydropyridines (1,4-DHPs) are well-knowncompounds because of their pharmacological pro-perty as calcium channel modulators[1, . The che- 2]mical modifications, such as the introduction of dif-ferent substituents[3, or heteroatoms[5], of the DHP 4]ring have allowed the expansion of researches onthe structure-activity relationship to gain new in-sights into the molecular interactions at the receptorlevel. In fact, it is well established th…     

Two-dimensional catena–polymer [[[bis (µ-aqua)(bis (µ-cpiap-K2O1:O2)sodium(I))] (µ-chlorido) bis(µ-cpiap-K5N1:O1:O2:O3,O3′)dicopper(II)]bis(µ-aqua)(aqua)bis(cpiap-K2O1,O2)copper(II)] hexa hydrate

The new title two-dimensional hetero-tetra nuclear Cu₃–Na coordination polymer {[NaCu₃Cl(cpiap)₂(H₂O)₃]_n·6nH₂O} (1) consists of crystallographically two-independent copper(II) centers, each bridged by a sodium cation through carboxylate-oxygen of the deprotonated H₃cpiap ligand (H₃cpiap = 2-(carboxyphenyl)iminoaceticpropanoic acid) to Cu^II (2) and Cu^II (2⁻) cations, and through water molecules to Cu^II (1) cation. Cu^II (2) and Cu^II (1) cations are bridged by carboxylate-oxygen atoms of the ligand in a syn-anti mode which, alternate regularly within the chain being bridged by a tetra coordinated sodium cation. Each Cu^II (2) and Cu^II (2⁻) cation in (1) is in an octahedral environment formed by four carboxylate-oxygens from two cpiap³⁻ ligands, one nitrogen atom and a bridging chloride atom. Cu^II (1) cation is in a square pyramidal environment formed by three water molecules and two carboxylate-oxygens from two cpiap³⁻ ligands. The ligand acts simultaneously as monodentate and tridentate toward Cu^II (1) and Cu^II (2) cations respectively. The lattice water molecules involved in OH···O hydrogen bonding are situated in the void spaces between layers. The zigzag chains, which run along the b-axes further construct three-dimensional metal-organic framework via hydrogen bonding and weak face-to-face π-π interactions. Weak CH···O interactions are also present.     

Crystal Structure and Biological Activities of （R）-N′-[2-（4-Methoxy-6-chloro）-pyrimidinyl]- N-[3-methyl-2-（4-chlorophenyl）butyryl]-urea

1 INTRODUCTION The acyl ureas are a kind of high biological acti- vity compounds with low toxicity to mammals, birds, fish, amphibians, etc., and significant organic synthe- sis intermediates working extensively as insecticides, pesticides, fungicides and herbicides in agrochemi- cal industry[1～7]. While pyrimidinyl derivatives show excellent biological activities in the development of pesticide, and are used to develop high effective and high select herbicides. For example, pyrimidiny su…     

Static atomic displacements of Sn in disordered NiAs/Ni2In type HT-Ni1+δSn

The crystal structures of the intermediate solid solution HT (high temperature) Ni_1+δSn with δ=0.28, 0.52 and 0.61 (refined Ni contents) have been analyzed in detail by X-ray diffraction on single crystals. The previously reported basic atomic arrangement, i.e., a NiAs/Ni₂In structure type (P6₃/mmc, Ni(1) on 2a, 0 0 0, Ni(2) with an occupancy δ on 2d, and Sn on 2c, ), is confirmed. However, strong anisotropic atomic displacements occur for Sn within the a-b plane of the hexagonal unit cell, which require a Gram-Charlier expansion of the probability density function of Sn in order to obtain a good fit to the diffraction data. Direction, magnitude and the concentration dependence of the displacements can be interpreted in terms of the geometrical requirements of the different local atomic configurations in the planes z=±1/4, so that the displacements can be identified as static ones.     

Physicochemical and structural properties of bacteriostatic sulfonamides: Theoretical study

A theoretical study at the Hartree–Fock and density functional theory levels is performed on sulfonamide‐type bacteriostatic compounds with the aim to provide an insight into their structure–activity relationship. The basicity of the p‐amino group is analyzed by means of the proton affinities and the protonation energies, showing that molecules presenting bacteriostatic activity are less basic, i.e., they are characterized by larger protonation energies and smaller proton affinities. The acidity of the amide group is analyzed through the deprotonation energy. The results reveal that the more acidic molecules present a larger bacteriostatic activity. This result is also confirmed from a study of bond orders. A bond order analysis of the amide group suggests that the electron attracting group in these molecules is responsible for the increase in acidity. The charge of the SO₂ group is also shown to be affected by the presence of the electron attracting group and consequently related to the acidity of the molecules. A geometric analysis shows that structures in which the amino group is more coplanar with respect to the benzenic ring possess larger bacteriostatic activity. A conformational analysis of these molecules illustrates that active molecules have relatively larger torsion energy barriers. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 94: 165–172, 2003     

Tl2S: Re-Determination of Crystal Structure and Stereochemical Discussion

The crystal structure of synthetic carlinite, Tl₂S, was re-determined by single crystal and powder X-ray diffraction methods. The cell parameters obtained from Rietveld refinement are a=12.150(2) Å, c=18.190(4) Å, V=2325.5(7) ų. A single crystal data refinement proved Tl₂S crystallizing in the trigonal space group R3 with M=440.8gmol⁻¹, Z=27, R=0.076, and wR=0.145. The atomic arrangement found is that of a strongly deformed anti-CdI₂ type, but the deformation is clearly different from that given by previous workers. In the five crystallographically different STl₆ octahedra the S-Tl distances vary between 2.82 and 3.09Å, the Tl-Tl edges between 3.52 and 4.58Å. The common features of these octahedra are (i) each one with a definitely smaller vs larger Tl₃ face in trans-position, both faces parallel or sub-parallel (00.1), and (ii) each three shorter and longer S-Tl distances to the atoms of the larger and smaller Tl₃ faces, respectively. The Tl-Tl contacts between different Tl₂S sheets are on the average definitely shorter than the ones within the sheet and they can be smaller than the Tl-Tl contacts in the small Tl₃ faces of the STl₆ octahedra. The atomic arrangement indicates that the single electron pairs of the monovalent Tl atoms are not arranged all parallel to the z-axis, as one would expect for Tl₂S with an ideal anti-CdI₂ structure. The surrounding of the S atoms resembles that of one-third of the Cl atoms in yellow InCl. The absorbance of Tl₂S is very low at wave numbers approximately <9000 cm⁻¹.     

四核钼簇合物的配体取代反应及产物Mo4S4(μ-OAc)2(dtp)4的晶体结构

标题化合物(Ⅰ)经由Mo₄S₄(μ-dtp)₄(Ⅱ)[dtp=S₂P(OEt)₂]和Ni(OAc)₂反应而得。(Ⅰ)晶体属单斜晶系,空间群P2/c,a=13.176(4),b=11.699(3),c=18.526(4)Å,β=116.11(3)°,V=2564(3)ų,Z     

Darstellung,Eigenschaften und Kristallstruktur von Bis(phthalocyaninato)cer(IV)

Preparation, Properties and Crystal Structure of Bis(phthalocyaninato)cerium(IV) The anodic or chemical oxidation with dibenzoylperoxide of solutions of bis(phthalocyaninato)cerate(III) in dichloromethane yields selectively sparely soluble bis(phthalocyaninato)cerium(IV), [Ce(Pc(2-)) 2 ]. Green, monoclinic needles cristallize with a = 18.783(12) Å b = 18.739(16) Å c= 15.618(10) Å ß114.30(7)°; Z = 4; space group C2/c. [Ce(Pc(2–)) 2 ] is a sandwich complex in which the cerium Atom is eightfold coordinated by the isoindole nitrogens of the two staggered convex Pc-rings. The u.v.-vis., m.i.r., f.i.r. and resonance Raman spectra are consistent with the structure.     

DFT方法理论研究星际分子C3S+结构和光谱

在B3LYP／6—31lG(d)水平上对可能的星际分子C3S^ 的各种异构体进行了理论计算研究，得到其几何构型、红外光谱和精确能量以利于实验室和星际观测，讨论了其星际含义，并与其中性分子C3S做了比较．结果表明：C3S^ 有3个稳定的异构体，包括线形、三元环和四元环几何构型．按热力学稳定的异构体依次是直线型具有C∞v对称性的CCCS^ (1)，其次是具有CC桥键四元环构型的cC3S^ (2)，能量最高是三元环构型具有CC环外键的C—cCCS^ (3)。