Synthesis and x-ray diffraction study of rhodium and iridium hexanitrite plumbates

Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 1, pp. 141–143, January–February, 1994.     

Synthesis and x-ray diffraction study of 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-n-acetic acid dihydroperchlorate

The dihydroperchlorate of 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-N-acetic acid (I) was obtained by the exchange reaction of the dihydrobromide with silver perchlorate. A planar structure of the ligand molecule with methyl and CH₂COOH groups that deviate from the plane of the macroring was established as a result of x-ray diffraction analysis. Numerous hydrogen bonds with the participation of a carboxy group, amino nitrogen atoms, and crystallization water molecules were detected.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1572–1575, November, 1992.     

Synthesis, characterization and thermal decomposition of thiourea complexes of antimony and bismuth triiodide

The thiourea complexes of antimony and bismuth triiodide were synthesized by a direct reaction of antimony and bismuth triiodide with thiourea powder at room temperature. The formula of the complex is MI₃[SC(NH₂)₂]₃(M=Sb, Bi). The crystal structure of the complexes belongs to monoclinic system and the lattice parameters are a=1.4772 nm, b=1.6582 nm, c=2.0674 nm and β=90.81° for SbI₃(SC(NH₂)₂)₃ and a=1.4009 nm, b=2.0170 nm, c=2.0397 nm and β=90.84° for BiI₃[SC(NH₂)₂]₃. The infrared spectra reveal that the trivalent antimony or bismuth ion is coordinated by the nitrogen atom, not the sulfur atom of the thiourea. Thermal analysis shows that there are two times structure rearrangements or phase transformation in the complexes from 100 to 170°C.     

Synthesis and x-ray structural examination of intracomplex boroxadiazolidines

The reaction between acetone monoalkylhydrazones and aldehydes in the presence of boric acid derivatives has given five-membered boron-nitrogen heterocycles, the stability of which is to a large extent dependent on the substituents in the ring. An x-ray structural examination of the boroxadiazolidine (VI) has been carried out.Deceased.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 178–182, January, 1991.     

Crystal and molecular structure of diphenyliodonium triiodide

A new salt diphenyliodonium triiodide (C₁₂H₁₀I₄) was obtained. The [C₁₂H₁₀I⁺][I₃⁻] compound was isolated as red brown crystals and studied by single-crystal X-ray diffraction. The structure of diphenyliodonium triiodide consists of separate, virtually linear I₃⁻ anions and C₁₂H₁₀I⁺ cations. Strong intermolecular anion-anion (I₃⁻…I₃⁻) and anion-cation (I₃⁻…I⁺) interactions in the crystal structure leads to a change in the symmetry of triiodide ions. The complex formation in the system organic cation iodide-elementary iodine was studied by spectrophotometry. The complex composition was found (1: 1), and the stability constant of the complex in chloroform was determined (loggB = 3.91).     

Synthesis and x-ray crystal structure of a tripeptidic cyclol

Properties, spectral data and X-ray crystallographic analysis of a tetracyclic tripeptidic aza-cyclol, obtained by cyclization of CF₃COOH·Pro-Phe-Pro-CNp in aqueous medium, are reported.     

Synthesis,characterization, and x-ray structural study of binary lithium managanese(II) molybdate

The binary molybdate of variable composition Li_2?2nMn_2+x(MoO₄)₃ (O2Fe₂(MoO₄)₃, was discovered in the Li₂MoO₄-MnMoO₄ system. We have grown single crystals of Li_1.60Mn_2.20(MoO₄)₃) and determined its crystal structure (space group Pnma, a=5.145, b=10.681, c=17.985 Å, Z=4). Along with statistical arrangement of Li and Mn in three different atomic positions, cation vacancies in one of these were found. Based on the data obtained, we propose to revise the compositions of some lithium-containing phases with the Li₂Fe₂(MoO₄)₃-type structure.     

2,2'-联吡啶二氢双三碘基盐(2,2'-bipyH2)(I3)2的合成、晶体结构和谱学性质

合成了标题化合物并测定其晶体结构.晶体属三斜晶系,P1空间群,α=0.80284(8)nm,b=0.95993(6)nm,c=0.71660(9)nm,α=102.016(9)°,β=111.933(9)°,γ=101.650(8)°,V=0.4767(1)nm³,Z=1,D_c=3.21g·cm^-3,F(000)=404,μ(MoK_a)=98.77cm^-1.晶体中存在反式平面型的(2,2'-bipyH₂)²⁺阳离子和线性的I₃^-阴离子.晶体由[(2,2'-bipyH₂)(I₃)₂]_∞链堆积而成,同一层的链间存在N-H···I氢键,氢键键长N···I为0.349nm.用UV-Vis光谱和¹H NMR谱对标题化合物进行了表征.     

Synthesis of a wide range of thioethers by indium triiodide catalyzed direct coupling between alkyl acetates and thiosilanes

An indium triiodide-catalyzed substitution of the acetoxy group in alkyl acetates with thiosilanes provides access to a variety of thioethers. The method is efficient for a wide scope of acetates such as primary alkyl, secondary alkyl, tertiary alkyl, allylic, benzylic, and propargylic acetates.     

Synchrotron x-ray photoemission study of soft x-ray processed ultrathin glycine-water ice films

Ultrathin glycine-water ice films have been prepared in ultrahigh vacuum by condensation of H(2)O and glycine at 90 K on single crystalline alumina surfaces and processed by soft x-ray (610 eV) exposure for up to 60 min. The physicochemical changes in the films were monitored using synchrotron x-ray photoemission spectroscopy. Two films with different amounts of H(2)O have been considered in order to evaluate the influence of the water ice content on the radiation-induced effects. The analysis of C1s, N1s, and O1s spectral regions together with the changes in the valence band spectra indicates that amino acid degradation occurs fast mainly via decarboxylation and deamination of pristine molecules. Enrichment of the x-ray exposed surfaces with fragments with carbon atoms without strong electronegative substituents (C-C and C-H) is documented as well. In the thinner glycine-water ice film (six layers of glycine + six layers of water) the 3D ice suffers strongly from the x-rays and is largely removed from the sample. The rate of photodecomposition of glycine in this film is about 30% higher than for glycine in the thicker film (6 layers of glycine + 60 layers of water). The photoemission results suggest that the destruction of amino acid molecules is caused by the direct interaction with the radiation and that no chemical attack of glycine by the species released by water radiolysis is detected.     

Crystal structure and two-level supramolecular organization of glycinium triiodide

Glycinium triiodide was synthesized and its crystal structure was determined. The crystal structure consists of alternating asymmetric triiodide anions characterized by Raman spectroscopy and glycinium cations. The cations and anions form dimers (GlyH)₂(I₃)₂via (N)H···O, (N)H···I, and (O)H···I hydrogen bonds. The dimers are further linked into chains by secondary I···I interactions between adjacent triiodide anions. The supramolecular structure of glycinium triiodide is discussed in comparison with polyiodides of various cations.

     

Dihydrobis(methylamine)borate triiodide

Both cation and anion in the title compound, C₂H₁₂BN₂⁺·I₃⁻, lie on a crystallographic mirror plane and are bound in the lattice by N—H⋯I⁻ hydrogen bonds, forming layers. Methyl‐H–borane‐H dihydride [–C—H(δ⁺)⋯(δ⁻)H—B–] inter­actions between mol­ecules crosslink adjacent layers, giving `sandwich' stacking along the a axis.     

Dibenzo-18-crown-6 diaqua(dibenzo-18-crown-6)potassium triiodide: Synthesis and crystal structure

A new compound, dibenzo-18-crown-6 diaqua(dibenzo-18-crown-6)potassium triiodide [K(Db18C6)(H₂O)₂)⁺ · I₃⁻ · Db18C6 (I), is synthesized and studied by X-ray crystallography. The crystals of compound I are orthorhombic: a = 22.065 ?, b = 22.140 ?, c = 9.433 ?, Z = 4, space group Pccn. Structure I is solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.098 for all 5974 unique reflections. Structure I contains the following asymmetric units: a half of the I₃⁻ centrosymmetric anion and two halves of the mixed equally average [K(Db18C6)(H₂O)₂]⁺ host—guest complex cation (a) and a free Db18C6 molecule, each stacked on the axes 2 of the perpendicularly averaged plane of the eighteen-membered macroheterocycle. In complex I, both Db18C6 molecules (a and b) have a “butterfly” conformation with approximate symmetry C _2v . Original Russian Text ? A.N. Chekhlov, 2009, published in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 3, pp. 516–520.     

A Raman spectroscopic study of the effect of ion-pairing on the structure of the triiodide and tribromide ions

The changes in the Raman spectra of aqueous solutions of I₂ in HI (1:1 mole ratio) with changing concentration, have been shown to be a result of ion-pairing: H⁺ + I⁻₃ = H⁺I⁻₃.The anomalous high frequency stretching band of the solute at 172 cm⁻¹ for these solutions arises mainly from stretching of the stronger II bond in the H⁺I⁻₃ ion-pair and not from vibrational modes of I₂ or I⁻₅. Ion-pair dissociation constants estimated from the Fuoss equation, combined with the known I⁻₃ ion-pair and not from vibrational modes of I₂ or I⁻₅. Ion-pair dissociation constants estimated from the Fuoss equation, combined with the known I⁻₃ and I⁻₅ formation constants, account for the intensity changes of the stretching bands. The spectra of solutions of Br₂/HBr at 1:1 mole ratio may be interpreted in the same way but other Br species are present. The spectra of the isolated X⁻₃ ions in solution exhibit a shoulder to high frequency of the symmetric stretching band, ν₁. In the spectrum of the I⁻₃ ion, this peak is assigned to one of the two frequencies, resulting from Fermi resonance between ν₁ and 2ν₂ but, in the case of the Br⁻₃ ion, this peak may be due to ν₃, which becomes Raman active as a result of disymmetric solvation. The consequences of such ion-pairing for the nature of I₂ dissolved in polymers are discussed.