Preparation of cadmium sulfide from CdCl2(CdBr2, CdI2)-CS(NH2)2-CH3OH systems

Summary The solubility isotherms of the ternary systems CdX₂-CS(NH₂)₂-CH₃OH (X = Cl, Br, I) at 25°C have been investigated. The fields of equilibrium existence of the salts CdCl₂·2CH₃OH, CdCl₂·2CS(NH₂)₂, CS(NH₂)₂, CdBr₂·3CH₃OH, CdBr₂·CS(NH₂)₂, CdBr₂·2CS(NH₂)₂, CdI₂ and CdI₂·2CS(NH₂)₂ were determined. The formation of CdS by thermal dissociation of double salts and saturated solutions is discussed.

---

Kadmiumsulfid-Herstellung aus CdCl₂(CdBr₂,CdI₂)-CS(NH₂)₂-CH₃OH — Systemen

Zusammenfassung Die Löslichkeitskurven der ternären Systeme CdX₂-CS(NH₂)₂-CH₃OH (X = Cl, Br, I) wurden untersucht. Die Gleichgewichtsbereiche der Salze CdCl₂·2CH₃OH, CdCl₂·2CS(NH₂)₂, CS(NH₂)₂, CdBr₂·3CH₃OH, CdBr₂·CS(NH₂)₂, CdBr₂·2CS(NH₂)₂, CdI₂ und CdI₂·2CS(NH₂)₂ wurden bestimmt. Die Bildung von CdS als durch thermische Zersetzung von Doppelsalzen und gesättigten Lösungen wird diskutiert.

     

A study of the system CdO-SeO2-H2O at 25 and 100°C

The solubility of the system CdO-SeO₂-H₂O was studied at 25 and 100°C. The fields of crystallization of α-CdSeO₃, 3CdSeO₃·H₂SeO₃ and CdSeO₃·SeO₂ were established at 25°C. At 100°C crystallize α-CdSeO₃, 3CdSeO₃·SeO₂, 2CdSeO₃·SeO₂ and CdSeO₃·SeO₂. The compounds obtained were identified by means of chemical, X-ray and crystal-optical analysis. The mechanism of thermal dissociation of α-CdSeO₃, 3CdSeO₃·H₂SeO₃ and CdSeO₃·SeO₂ was studied. This revised version was published online in August 2006 with corrections to the Cover Date.     

A Cadmium(II) Coordination Polymer:Crystal Structure and Fluorescent Property of [CdCl2(4,4''-bipyridine)]∞

The reaction of L-histidine,CdCl2(2.5H2O and 4,4'-bipyridine in methane/water gave rise to a two-dimensional coordination polymer [CdCl2(4,4'-bipyridine)]( which has been characterized by single-crystal X-ray diffraction.The polymer crystallizes in the orthorhombic sys-tem,space group Cmmm with a = 12.083(7),b = 11.771(7),c = 3.781(2)(A),V = 537.8(6)(A)3,Z = 2,C10H8N2CdCl2,Mr = 339.48,Dc = 2.097 g/cm3,F(000) = 328 and μ(MoKα) = 2.490 mm-1.The final R = 0.0658 and wR = 0.1398 for 257 observed reflections with I≥2σ(I).     

Crystal Structure,Magnetic Properties,and Electronic Structure of Ni(NCNH2)4Cl2 and Co(NCNH2)4Cl2

The crystal structures of Ni(NCNH₂)₄Cl₂ and Co(NCNH₂)₄Cl₂, the first complexes with cyanamide as a neutral ligand, have been determined from single crystal data (Im3m, Z = 6, a = 1259.3(2) pm, R₁ = 0.0245 for Ni(NCNH₂)₄Cl₂ and a = 1266.3(2) pm, R₁ = 0.0241 for Co(NCNH₂)₄Cl₂; both 329 intensities and 23 parameters). Ni²⁺ and Co²⁺ are octahedrally coordinated by four equatorial H₂NCN molecules and two axial chloride ions, and the 20 and 19 electron octahedral complexes are connected by a network of hydrogen bonds. The cyanamide ligands are slightly bent (166°), and the two N–C distances are 112 and 133 pm. Ni(NCNH₂)₄Cl₂/Co(NCNH₂)₄Cl₂ are Curie paramagnets with two/three unpaired electrons.     

二苄基N,N-二甲基荒酸锡的合成及晶体结构研究

用二苄基二氯化锡与N,N-二甲基荒酸钠反应合成了化合物(PhCH2)2Sn[S2CN(CH3)2]2,通过X-射线确定了其晶体结构,晶胞参数为单斜晶系,空间群P21/n,a=13.926(5), b=9.832(4), c=17.080(7),β=103.541(6)°, V=2273.7(15)3, Z=4.     

Probing the ultrafast photoelectron spectra of Br2 molecule

The time‐dependent‐wave‐packet method is applied to study the ionization of Br₂ molecule with four ionization processes. The ground state absorption makes the photoelectron to be left in the three final ionic states: Br (X²∑), Br (A²∏_u), and Br (B²∑), and each population of these ionic states is related with the laser intensities. The information of the dissociation can be got by analyzing the photoelectron features of the transient wave packet, which also suggests that an ionization process occurs during the dissociation, and the Br atoms that mainly resulted from the dissociation of Br₂ (C¹∏_u) are ionized at later time delays as the dissociation is nearly complete. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007     

Crystallographic report: Bis[tris(2‐pyridyl)amine]cadmium(II)‐di‐µ‐chloro‐dichloro‐cadmium(II), [(C5H4N)3N]2CdCl2CdCl2

In the dinuclear molecule of [(C₅H₄N)₃N]₂CdCl₂CdCl₂, one cadmium is octahedrally coordinated by a Cl₂N₄ donor set and the other cadmium is tetrahedrally coordinated by four chlorine atoms. The dinuclear units are connected by π–π interactions to give a two‐dimensional network. Copyright © 2003 John Wiley & Sons, Ltd.     

Synthesis and study of (2S,4S)-4-arylamino-2-carboxy-5-pyrrolidones

(2S,4S)-4-Arylamino-2-carboxy-5-pyrrolidones were prepared by hydrolysis of dimethyl (2S,4S)-4-arylamino-N-phthaloylglutamates. The protonation constants of the arylamino group in the synthesized compounds were determined. The pyrrolidone ring is stable in acidic or neutral solutions. The relative stability of the pyrrolidone ring in alkaline solutions was studied by IR spectroscopy.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2087–2090, December, 1993.     

乙硼烷(B~2H~6)在醚溶液中分解的理论研究

以二甲醚模拟四氢呋喃在乙硼烷分解过程中的作用。B3LYP/6-31G^*的计算结果发现,硼烷的分解是一个两步过程,每一步中均有一个醚分子与一个硼原子形成硼氧配位键,且只有一个氢桥键断裂。第一步反应的活化能为42.30kJ·mol^-^1,第二步的为4.33kJ·mol^-^1。当考虑溶剂效应时,第一步的活化能更降低为28.03kJ·mol^-^1。     

Die Reaktion von SePh2 mit N‐Chlorsuccinimid. Kristallstrukturen von [SeCl2Ph2] und [SeCl2Ph2(Succinimid)2]

Reaction of SePh₂ with N‐Chlorosuccinimide. Crystal Structures of [SeCl₂Ph₂] and [SeCl₂Ph₂(succinimide)₂] SePh₂ reacts with N‐chlorosuccinimide in acetonitrile solution to give [SeCl₂Ph₂] ( 1 ) and [SeCl₂Ph₂(succinimide)₂] ( 2 ) as colourless crystals, which can be separated by fractional crystallization. According to X‐ray single crystal determinations both compounds contain [SeCl₂Ph₂] molecules with ψ‐trigonal‐bipyramidal coordination at the selenium atom, the chloro ligands being in apical positions. In 2 the dimeric unit (HNC₄O₂H₄)₂ is linked with its [SeCl₂Ph₂] unit via a weak C–H···O hydrogen bond. 1 : Space group Pbcn, Z = 4, lattice dimensions at 193 K: a = 1350.6(1), b = 573.3(1), c = 1503.3(2) pm, R₁ = 0.0326. 2 : Space group I2/a, Z = 4, lattice dimensions at 193 K: a = 1363.9(1), b = 557.7(1), c = 2781.3(1) pm, β = 101.01(1)°, R₁ = 0.0286.     

Polarographic study of the complexes of cadmium(II) and lead(II) with methoxyacetate ions

Reduction of the complexes of cadmium(II) and lead(II) atdme in aqueous and aqueous-methanol media at μ = 1.0 M(NaClO₄) at 15 ±0.1 and 25 ±0.1°C is reversible and diffusion-controlled. Four complex species are formed in either case. The overall stability constants of 1:1,1:2, 1:3 and 1:4 complexes have been determined. Lead(II) complexes are much stronger than the corresponding cadmium(II) complexes.     

Photodetachment and photofragmentation pathways in the [(CO2)2(H2O)m]- cluster anions

The mass-selected [(CO(2))(2)(H(2)O)(m)](-) cluster anions are studied using a combination of photoelectron imaging and photofragment mass spectroscopy at 355 nm. Photoelectron imaging studies are carried out on the mass-selected parent cluster anions in the m=2-6 size range; photofragmentation results are presented for m=3-11. While the photoelectron images suggest possible coexistence of the CO(2) (-)(H(2)O)(m)CO(2) and (O(2)CCO(2))(-)(H(2)O)(m) parent cluster structures, particularly for m=2 and 3, only the CO(2) (-) based clusters are both required and sufficient to explain all fragmentation pathways for m>/=3. Three types of anionic photofragments are observed: CO(2) (-)(H(2)O)(k), O(-)(H(2)O)(k), and CO(3) (-)(H(2)O)(k), k6) is attributed to hindrance from the H(2)O molecules.     

Synthesis and Crystal Structure of DinuclearCadmium Complex [Cd2（phen）4（fca）2]（ClO4）2-（H2O）2

1 INTRODUCTION During the search of molecule-based materials with interesting properties such as catalysis, cla- thration etc., much attention has been focused on the synthesis of one-, two- and three-dimensional extended solids involving cadmium[1], as its d10 configuration permits a wide variety of geometries and coordination numbers. Rigid bridged ligands such as carboxylate groups are frequently used to construct these materials. Therefore, the coordi- nation chemistry of Cd(Ⅱ) ca…     

Kristallstrukturen von MgCr2O4-Typ Li2VCl4 und Spinell-Typ Li2MgCl4 und Li2CdCl4

Crystal Structures of MgCrO₄-type Li₂VCl₄ and Spinel-type Li₂MgCl₄ and Li₂CdCl₄ The crystal structures of the ternary lithium chlorides Li₂MCl₄ (M = Mg, V, Cd) have been determined firstly by X-ray single-crystal experiments. Li₂MgCl₄ and Li₂CdCl₄ crystallize in an inverse spinel structure (space group Fd3 m, Z = 8, a = 1 040.1(2) and 1 062.06(9) pm, structural parameters u = 0.25699(2) and 0.2550(1), R = 1.7 and 3.7% for 218 and 211 unique reflections). The Li? Cl distances of the tetrahedrally coordinated Li⁺ ions are significantly greater than calculated with Shannon's crystal radii ( > 238 ± 1 instead of 233 pm). Contrary to the results of X-ray powder data reported in the literature, Li₂VCl₄ crystallizes in the distorted spinel structure of MgCr₂O₄ type (space group F4 3m, Z = 8, a = 1 037.49(2) pm, R = 5.9% for 217 unique reflections). The decrease of the site symmetry of the octahedrally coordinated ions (V²⁺, Li⁺) from 3 m to 3m resulting in contracted and widened tetrahedral M₄ entities of the spinel structure is obviously caused by V? V metal—metal bonds (shortest V? V distance 366.2(7) pm).     

Quantum chemical study of chlorine-dissociation of oxalyl chloride (ClCO)_2→2Cl+2CO

It is very difficult to study the phenomenon that molecules are decomposed into several pho-tofragments by UV light, as the energy of lamp-house is insufficient. But the bond energy in oxa-lyl chloride is relatively low, for example, D0(ClCOCO-Cl) = 313.92 kJ/mol[1], D0(ClCO-CO) = 35.53 kJ/mol, and D0(Cl-CO) = 27.17 kJ/mol[2], so, oxalyl chloride, as a typical system for the study of multi-channel dissociation, can be dissociated into the four fragments Cl+Cl+CO+CO by the proper UV …     

An experimental and theoretical study of the Cp2VO2CO: use of 13CO3(2-) for structure investigation of d1-metallocene complexes

EPR study has shown that the anticancer agent vanadocene dichloride (Cp2VCl2) interacts with carbonate contained in physiological solutions. Chelate complex Cp2VO2CO (|A(iso)(51V)| = 175.1 MHz, g(iso) = 1.9861) is the only paramagnetic species formed in the range about the physiological pH (5.5-11.0). The super-hyperfine coupling (|a(iso)(13C)| = 24.1 MHz) was evidenced at measurements using 13C labelled carbonate. The structure of carbonate complex was validated by comparison of observed and theoretical calculated HFC tensors (at the density functional level of theory).     

2,6-Bis(methylencyclopentadienyl)-pyridin-zirconocen- und -hafnocendichlorid; Bildung und Kristallstruktur von [C5H3N-2,6-(CH2?C5H4)2Zr(Cl)(OH2)]2[ZrCl6]

2,6-Bis(methylenecyclopentadienyl)-pyridine-zirconocene and -hafnocene Dichloride; Formation and Crystal Structure of [C₅H₃N-2,6-(CH₂? C₅H₄)₂Zr(Cl)(OH₂)[ZrCl₆]] Pyridine bridged metallocene dichlorides of type C₅H₃N-2,6-(CH₂? C₅H₄)₂MCl₂ (M = Zr ( 2 ), Hf ( 5 )) were synthesized. The presence of N → Zr interaction favours the formation of zirconocene cations. Traces of water cause the formation of the salt-like compound [C₅H₃N-2,6-(CH₂? C₅H₄)₂Zr(Cl)(OH₂)]₂[ZrCl₆] 4 from 2 . The new compounds were characterized by ¹H n.m.r., and mass spectroscopy. The X-ray crystal structure of 4 shows discrete cations and anions which are connected by H-bridges.     

Observation of an unusually facile fragmentation pathway of gas-phase peptide ions: a study on the gas-phase fragmentation mechanism and energetics of tryptic peptides modified with 4-sulfophenyl isothiocyanate (SPITC) and 4-chlorosulfophenyl isocyanate (SPC) and their 18-crown-6 complexes

Various peptide modifications have been explored recently to facilitate the acquisition of sequence information. N-terminal sulfonation is an interesting modification because it allows unambiguous de novo sequencing of peptides, especially in conjunction with MALDI-PSD-TOF analysis; such modified peptide ions undergo fragmentation at energies lower than those required conventionally for unmodified peptide ions. In this study, we systematically investigated the fragmentation mechanisms of N-terminal sulfonated peptide ions prepared using two different N-terminal sulfonation reagents: 4-sulfophenyl isothiocyanate (SPITC) and 4-chlorosulfophenyl isocyanate (SPC). Collision-induced dissociation (CID) of the SPC-modified peptide ions produced a set of y-series ions that were more evenly distributed relative to those observed for the SPITC-modified peptides; y(n-1) ion peaks were consistently and significantly larger than the signals of the other y-ions. We experimentally investigated the differences between the dissociation energies of the SPITC- and SPC-modified peptide ions by comparing the MS/MS spectra of the complexes formed between the crown ether 18-crown-6 (CE) and the modified peptides. Upon CID, the complexes formed between 18-crown-6 ether and the protonated amino groups of C-terminal lysine residues underwent either peptide backbone fragmentation or complex dissociation. Although the crown ether complexes of the unmodified ([M + CE + 2H]2+) and SPC-modified ([M* + CE + 2H]2+) peptides underwent predominantly noncovalent complex dissociation upon CID, the low-energy dissociations of the crown ether complexes of the SPITC-modified peptides ([M' + CE + 2H]2+) unexpectedly resulted in peptide backbone fragmentations, along with a degree of complex dissociation. We performed quantum mechanical calculations to address the energetics of fragmentations observed for the modified peptides.