Приближенное решение задачи динамики гелеобразования

Рассмотрены уравнения, описывающие движение зонда вибрационного датчика вязкости в гелеобразующей вязкоупругой среде. Описано получение приближенных решений для определения вязкости и сдвиговой упругости, и проведено сравнение с точным решением

Structural and spectroscopic study of a five-coordinate rhodium(I) complex (η-1,5-cyclooctadiene)(η-2,6-diallylpyridine,N)rhodium (1+) with two different and unusual di-μ-chloro-bis[dichlorodimethylstannate](2-) anions: crystal structures of [Rh(C8H12)(C11H13N)]2[{SnCl3(CH3)2}2].2CH2Cl2 and [Rh(C8H12)(C11H13N)]2[{SnCl3(CH3)2}2]

The prepn. and crystal structures of a five-coordinate rhodium(I) complex with 2,6-diallylpyridine and cyclooctadiene (COD) ligands with two different [{SnCl3Me2}2]2- anions are described, including IR and 1H NMR data. In both structures the cationic Rh has a trigonal-bipyramidal environment with the N-pyridine and one double bond of the COD ligand in axial positions and the two allylic double bonds together with the other double COD bond in equatorial positions. Much more interesting are the structures of the anionic parts, which show a different unsym. dimerization through two chlorine bridges. The tin coordination polyhedra, which assume a distorted trigonal-bipyramidal geometry in the monomeric units, achieve an octahedral shape. There is a simple correlation between the Me-Sn-Me angle value and the longest Sn-Cl bond distance

Olefin ligands. Syntheses and structures of 2,6-diallylpyridine (DAP) complexes of rhodium(I); crystal structures of [Rh(COD)(DAP)][RhCl2(COD)] and [Rh(COD)(DAP)][CuCl2]

Reaction of 2,6-diallylpyridine (DAP) with Rh(I) compds. gave complexes of the type [RhCl(DAP)]n, RhCl(L)(DAP) (L = CO, PPh3), [Rh(diene)(DAP)]Y [diene = 1,5-cyclooctadiene (COD), norbornadiene (NBD); Y = [RhCl2(diene)], CuCl2, ClO4]. The crystal structures of [Rh(COD)(DAP)][RhCl2(COD)] and [Rh(COD)(DAP)][CuCl2] were detd. by x-ray crystallog. The crystals consisted of cationic [Rh(COD)(DAP)]+ and anionic [Rh(COD)Cl2]- and [CuCl2]- complexes, resp. The cations were similar in the two compds., and the coordination around the Rh atoms was trigonal bipyramidal, with a short Rh-N axial bond and 4 η2-C:C olefinic interactions

Olefin ligands. II. Syntheses of 2,6-diallylpyridine (DAP) complexes of iridium(I), ruthenium(II), palladium(II) and platinum(II); crystal structures of [RuCl2(PPh3)(DAP)] and [PdCl2(DAP)2]

The tridentate ligand 2,6-diallylpyridine (DAP) has been used to synthesize novel complexes [Ir(COD)(DAP)][IrCl2(COD)], [IrCl(CO)(DAP)], [Ir(COD)(DAP)]ClO4, [RuCl2(PPh3)(DAP)], [PdCl2(DAP)2], [PtCl2(DAP)] (COD = 1,5-cyclooctadiene). The mol. structures of [RuCl2(PPh3)(DAP)] and [PdCl2(DAP)2] have been detd. by single-crystal x-ray diffraction studies. In the octahedral Ru complex, DAP acts as a tridentate ligand adopting a mer configuration and the phosphine ligand is trans to the pyridinic N, while in the trans square-planar Pd complex DAP acts as a monodentate N-donor ligand

Regioselective aerobic oxidation of bis-sulfides into monosulfoxides

The cobalt(II)acetylacetonate/aldehyde-promoted aerobic oxidation of three bis-sulfides of general formula R1- SCH2CH2S-R2, where R1 is a heterocycle and R2 is p-tolyl, provides a method to functionalise selectively the sulfur atom bonded to the p-tolyl moiety leading to the corresponding monosulfoxides. The same chemoselectivity and little diastereoisomeric excess (10%). was achieved by submitting to oxidative conditions the chiral bis-sulfide (5)-R3- SCH2CHCH3.CH2-SR4 (R3sbenzothiazolyl, R4sp-tolyl)

Western Star, 1914-11-11

The Western Star began publication on Newfoundland's west coast on 4 April 1900, appearing weekly with brief semiweekly periods up to 1952, when it became a daily. As of 17 April 2019 it continues as a free weekly community paper