The reactions of [(thf)2TiCl4] with sodiated 2,2’-bis[2-hydroxy-3,5-di(tert-butyl)benzylideneamino]-1,1’-biphenyl (1 a) and 2,2’-bis[2-hydroxy-3,5-di(tert-butyl)benzylideneamino]-4,4’-dimethyl-1,1’-biphenyl b) yield the corresponding Ti complexes 2 a b. Similarly, 1 reacts [(thf)2ZrCl4] to Zr derivative 3. For a, mixture cis-β trans isomers were observed in solution whereas congener exclusively...

Based on an Atoms-in-Molecules (AIM) analysis, Matta et al. recently claimed evidence for the existence of hydrogen-hydrogen bonding between ortho-hydrogen atoms, pointing towards each other from adjacent phenyl groups in planar biphenyl. This AIM result is opposed to the classical view that nonbonded steric repulsion between the ortho-hydrogen atoms is responsible for the higher energy of the ...

The ability of the rabbit to metabolize naphthalene and chlorinated naphthalene was markedly influenced by the degree of halogenation of the compound according to Cornish and Block (2). Naphthalene is related structurally to biphenyl, in which a coaxial linkage connecta two phenyl molecules. Whethe? the presence of a chlorine atom in biphenyl also alters the metabolism of this compound as it, d...

The naphthalene dioxygenase (NDO) system catalyzes the first step in the degradation of naphthalene by Pseudomonas sp. strain NCIB 9816-4. The enzyme has a broad substrate range and catalyzes several types of reactions including cis-dihydroxylation, monooxygenation, and desaturation. Substitution of valine or leucine at Phe-352 near the active site iron in the alpha subunit of NDO altered the s...

Some derivatives of biphenyl-4-carboxylic acid 2-(aryl)-4-oxo-thiazolidin-3-yl –amide were synthesized and studied for their antimicrobial activity. These compounds were prepared from biphenyl-4-carboxylic-acid hydrazides. Biphenyl-4-carboxylic-acid hydrazides 1 on refluxing with aryl aldehydes in the presence of catalytic amount of glacial acetic acid furnish the biphenyl-4-carboxylic acid hyd...

Vapor-phase methylation of toluene using methanol and its isopropylation with 2-propanol has been investigated ina down flow reactor under atmospheric conditions using N2 carrier over a series of surface modified andunmodified ZSM-5 (Si/Al= 60-170) loaded with H3PO4, differing in the external surface treatment of the zeolites.The feed molar ratios of toluene/methanol and toluene/2-propanol were...

Alkylating agents, mechlorethamine and N-methyl-N'-nitro-N-nitrosoguanidine, induce the production of plasminogen activator in U-87MG cells, an alkylation DNA repair deficient (Mer-) human glioblastoma strain. Enzyme induction was not observed, however, in U-178MG and SH-101 cells, alkylation repair proficient (Mer+) glioblastoma strains, or in HeLa cells, which reactivated and supported well t...

The oxygenase component of biphenyl dioxygenase (BPDO) from Comamonas testosteroni B-356 dihydroxylates biphenyl and some polychlorinated biphenyls (PCBs), thereby initiating their degradation. Overexpressed, anaerobically purified BPDO had a specific activity of 4.9 units/mg, and its oxygenase component appeared to contain a full complement of Fe(2)S(2) center and catalytic iron. Oxygenase cry...

Polychlorinated biphenyls (PCBs), the chlorinated derivatives of biphenyl, are one of the most prevalent, highly toxic and persistent groups of contaminants in the environment. The objective of this study was to investigate the biodegradation of PCBs in northeastern (Heilongjiang Province), northern (Shanxi Province) and eastern China (Shanghai municipality). From these areas, nine soil samples...