The reactions of a variety of bis(tricyclohexylphosphine)nickel species with C 0 2 have been studied. The product of the reaction is solvent dependent: in toluene the known complex [NiL2(/7 -C02)]-toluene (L = PCy3) is formed while in ether or pentane a binuclear complex [(NiL2)2(?;-C02)] results through the intermediacy of the solvent free species [NiL2(//-C02)] the structure of which has been...

Crown-ether like interaction of two neutral [Cu2(μ-OH)(μ-L(1))] (H3L(1) = 2-(2'-hydroxyphenyl)-1,3-bis[4-(2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine) fragments, around a central Na(+) cation as self-assembly template, led to the formation of [Na{Cu2(μ-OH)(μ-L(1))}2]ClO4 (1). Di-tert-butyl group substituted H3L(2) {2-(3,5-di-tert-butyl-2-hydroxyphenyl)-1,3-bis[4-(3,5-di-tert-butyl-2-hyd...

Cyclocondensation between 4,4`-bis(4-chlorobenzenesulfonyl)biphenyl and catechol, with subsequent chromatographic separation of the reaction products, led to isolation four novel ether-sulfone macrocycles (cyclic dimer, -trimer, -tetramer -pentamer). Similarly, cyclocondensation catechol a seven-ring diketone/disulfone monomer allowed two new aromatic ether-ketone-sulfone macrocycles, cyclic di...

1. The activity of chicken pepsin was partially inhibited by dimethyl-(2-hydroxy-5-nitrobenzyl)sulphonium bromide, but was unaffected by p-bromophenacyl bromide. 2. In the presence of Cu2+, diazoacetylnorleucine methyl ester completely inactivated chicken pepsin with the incorporation of 1 mol/mol. The mechanism of the reaction was similar to that with pig pepsin. 3. Chicken pepsin was complete...

Ether-solvated contact and separated ion pairs (CIP and SIP) for two lithium reagents, tris(trimethylsilyl)methyllithium (1) and bis(3,5-bistrifluoromethylphenylthio)methyllithium (2), have been characterized and observed for the first time under conditions of slow exchange by NMR spectroscopy, and barriers to interconversion have been measured. A Saunders isotope perturbation experiment was us...

By free radical addition of ethanedithiol to alkyl- and cycloalkyl-substituted methylene dioxolanes, the bis-adducts tested then as a plasticizer for PVC have been obtained. It has established result carried out investigations that introduction synthesized compounds into composition improves physical-mechanical properties, which connected with availability sulfur atoms, carbonyl groups ether bo...

Nitriles have been shown to be effective vibrational probes of local environments in proteins but have yet to be fully utilized for the study of nucleic acids. The potential utility of 5-cyano-2'-deoxyuridine ( 1) as a probe of local nucleic acid environment was investigated by measuring the dependence of the IR nitrile stretching frequency (nu CN), line shape, and absorbance on solvent and tem...

The total synthesis of (-)-cytoxazone 1 was achieved in six linear steps (34% overall yield) from p-anisaldehyde. The key steps in this route are the regioselective and stereoselective introduction of a N-protected amine group, using the CSI reaction of the anti-1,2-dimethyl ether 3, and the subsequent regioselective cyclization of the N-protected amino diol 13 to give the 2-oxazolidinone unit ...