Synthesis and the crystal structure of the triosmium cluster with the μ-dehydrobenzene ligand,Os3(μ-H)2(CO)7(μ-C6H4){μ3-Ph2PCH2P(C6H4)Ph}

The Os₃(-H)₂(CO)₇(-C₆H₄){₃-Ph₂PCH₂P(C₆H₄)Ph} complex, which was isolated from the products of thermolysis of Os₃(CO)₁₀(-dppm) (dppm is Ph₂PCH₂PPh₂) in toluene, was characterized by X-ray diffraction analysis. Protonation of the resulting complex with trifluoroacetic acid afforded the cationic complex [Os₃(-H)₃(CO)₇(-C₆H₄){₃-Ph₂PCH₂P(C₆H₄)Ph}]⁺.     

Cobalt-zeolite catalysts for the synthesis of hydrocarbons from CO and H2

Catalysts prepared by mechanical mixing of high-silica zeolite ZSM-5 with cobalt oxide Co₃O₄, basic cobaltous carbonate, and cobaltous carbonate were studied. The nature of the cobalt compound introduced into the mixture affects the catalytic and physicochemical properties of the catalyst. The presence of Co₃O₄ in the sample (introduced as oxide or obtained by thermal decomposition of the carbonate) is favorable to the formation of aromatic compounds from CO and H₂. The use of cobaltous carbonates for the preparation of catalysts results in development of the porous structure of the catalyst. During preparation of samples, the mechanical treatment partially destroys the zeolite framework of the support.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1070–1073, June, 1995.     

Effect of the mobility of charged units on the microphase separation in amphiphilic polyelectrolyte hydrogels

The effect of the migration of charged units on the structure of hydrophobically modified polyelectrolyte gels swollen by D(2)O was studied by small-angle neutron scattering on an example of gels of terpolymers of acrylic acid, n-dodecylacrylate, and 2-acrylamido-2-methyl-1-propanesulfonic acid (quenched charged units) and gels of copolymers of partially neutralized acrylic acid and n-dodecylacrylate (annealed charged units). The content of charged units did not exceed 20 mol %, so that the electrostatic repulsion was too weak to disrupt the hydrophobic domains formed by self-assembled n-dodecyl chains, which was evidenced by NMR data. It was shown that upon increasing the charge content both types of gels undergo microphase separation with the formation of hydrophobic clusters consisting of several densely packed hydrophobic domains and hydrophilic regions swollen by water, where most of the charged repeat units and counterions are located. The dimensions of the nanostructure of the gels with quenched and annealed charged groups were compared. It was shown that the size of clusters in the gels with annealed charged units is much bigger than that in the gels with the same fraction of quenched charged units. This effect was attributed to a much weaker electrostatic repulsion in the corona of the hydrophobic clusters in the gels with annealed charged groups, because the charged units repelling each other are able to move farther apart.     

Reactions of iridium bis(phosphinite) pincer complexes with protic acids

Iridium pincer complexes [C₆H₃-2,6-(OPBu^t ₂)₂]Ir(H)Cl (10) and [4-EtOOCC₆H₂-2,6-(OPBu^t ₂)₂]Ir(H)Cl (11) react with protic acids undergoing metallation of one of the tert-butyl groups to form double cyclometallated products [4-R-C₆H₂-2-(OPBu^t ₂)-6-(OP(Bu^t)CMe₂CH₂)]IrCl (12, R = H; 13, R = COOEt), which are stable in air. Complex 12 reacts with CO and Bu^tNC giving the corresponding 18-electron complexes [C₆H₃-2-(OP-Bu^t ₂)-6-(OP(Bu^t)CMe₂CH₂)]Ir(L)Cl (14, L = CO; 15, L = CNBu^t). The structure of compound 14 was established by X-ray diffraction analysis.     

Iridium hydride complexes with P,C,P pincer ligands based on ferrocene and ruthenocene

Russian Chemical Bulletin -     

Palladium pincer complexes Pd(BH4)[{2,5-(R2PCH2)2C5H2}Fe(C5H5)] (R = Pri,But) with unidentate borohydride ligand

Russian Chemical Bulletin -     

Evolutionary Algorithm-based Crystal Structure Prediction for Gold(I) Fluoride

Solid gold(I) fluoride remains as an unsynthesized and uncharacterized compound. We have performed a search for potential gold(I) fluoride crystal structures using USPEX evolutionary algorithm and dispersion-corrected hybrid density functional methods. Over 4000 AuF crystal structures have been investigated. Behavior of the AuF crystal structures under pressure was studied up to 25 GPa, and we also evaluated the thermodynamic stability of the hypothetical AuF crystal structures with respect to AuF₃, AuF₅, and Au₃F₈. Mixed-valence compound Au₃[AuF₄] with Au atoms in various formal oxidation states emerged as the thermodynamically most stable AuF species.     

New π-conjugated electroluminescent polymers containing organoiridium quinolinolate complexes in the backbone and light diodes formed on their basis

New conjugated copolyfluorenes containing covalently bound quinolinolate complexes of iridium in the backbone are synthesized under conditions of the Yamamoto reaction. The structures and properties of the polymers are characterized via NMR spectroscopy, GPC, TMA, and TGA. All copolymers show solubility in common organic solvents and feature good thermal and thermo-oxidative properties. The absorption, luminescence, and electrochemical properties of the polymers are investigated. In thin films, the polymers emit blue light with wavelengths in the range 450–470 nm. The electroluminescence spectra of the copolymers show broad intense bands in the visible region with maxima at 500–525 nm corresponding to various emission colors with the chromaticity coordinates (0.361, 0.437) and (0.247, 0.411). The synthesized iridium-containing copolyfluorenes may be used as electron-hole transport materials in light-emitting diodes.     

Synthesis and comparative X-ray diffraction study of first ruthenocene-based pincer palladium complexes, PdCl[{2,5-(But 2PCH2)2C5H2}Ru(Cp′)] (Cp′ = C5H5 or C5Me5)

First ruthenocene-based palladium complexes PdCl[{2,5-(Bu^t ₂PCH₂)₂C₅H₂} Ru(Cp′)] (Cp′ = C₅H₅ (4) or C₅Me₅ (5)) were synthesized. Comparative single-crystal X-ray diffraction study of complexes 4 and 5 showed that the deviations of the cyclopentadienyl rings in these complexes from being parallel are 2.6 and 10.1°, respectively. In addition, the shift of the palladium atom relative to the plane of the metallated cyclopentadienyl ligand is 0.007 Å for 4 and 0.336 Å for 5. These differences in the structures of complexes 4 and 5 are due to close contacts between the pseudoequatorial tert-butyl groups at the phosphorus atoms and the unmetallated cyclopentadienyl ring. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1879–1884, November, 2006.