The temperature dependence of the e.s.r. spectrum of the radical cation of dodecahydrotriphenylene (2∔) shows that the activation energy for inversion of the (benzo)cyclohexene ring is 4.8 kcal mol-1, less than it is in the octahydroanthracene radical cation (1∔).

Muonium has been used as an H atom analogue to investigate the free radicals formed by H addition to the fused polyaromatic hydrocarbon triphenylene. Although there are three inequivalent sites of attack in this molecule, only two radicals were detected. Muon and proton hyperfine constants were ...

The effective methylation of phosphonic acids related to chemical warfare agents (CWAs) employing trimethyloxonium tetrafluoroborate (TMO·BF4) for their qualitative detection and identification by gas chromatography-mass spectrometry (GC-MS) is presented. The methylation occurs in rapid fashion...

A novel phosphonic acid and triazolyl functionalized poly(ether sulfone) (PES-TriPA) containing simultaneously phosphonic acid and triazolyl side groups is synthesized. The PES-TriPA is prepared by polycondensation of phosphonated bisphenol (PBP) and 3,3′-diethynyl-4,4′-difluorodiphenylsulfone...

Synthesis and self-assembly of C60 fullerene phosphonic acid derivative onto magnetic iron oxide nanoparticles stabilized with oleic acid (OA) for catalytic applications is presented. The as obtained composite nanoparticles were characterized using transmission electron microscopy (TEM), dynamic...

A homologous series of mesogenic phosphonic acid derivatives (CnPA) were synthesized through the Michaelis-Becker reaction. Chemical structures of the derivatives were characterized by nuclear magnetic resonance, Fourier transform infrared spectroscopy and high-resolution mass spectrometry. Diff...

A new polar phosphinoferrocene ligand, viz. 1’-(diphenylphosphino)ferrocene-1-phosphonic acid (H2L), was prepared by hydrolysis of the corresponding phosphonate ethyl ester. However, the compound is relatively unstable, gradually decomposing upon prolonged storage, ultimately affording phosphin...

In this work, new doped Nafion membranes with enhanced proton conductivity were prepared to be used as proton exchange membranes in fuel cells. New dopants derived from arylmono- or bisphosphonic acid were prepared and incorporated into the new membranes using impregnation or casting methods. Pr...

Carbonyl–isocyanide-ruthenium(II) complexes cis,cis-[RuX2(CNR)(CO)(P∧P)] (P∧P = dppf, dippf; X = Cl, Br; R = Bn, Cy, tBu, 2,6-C6H3Me2, (S)-(−)-C(H)MePh) (3–6a–e) have been prepared in high yields by treatment of the dimeric derivatives [{RuX(μ-X)(CO)(P∧P)}2] (P∧P = dppf, dippf; X = Cl, B...

Tricyclohexylmethane has a melting point close to ambient temperature. Nevertheless the X-ray structure has been determined. The crystal is chiral but its chirality could not be established. The solid is unusual in that the atomic volume per carbon atom is 22.2 Å3 which is substantially greater ...

Prometon, a major soil sterilant, and its main transformation products, deisopropylprometon (N2-isopropyl-6-methoxy-1,3,5-triazine-2,4-diamine) and hydroxyprometon (4,6-bis(isopropylamino)-1,3,5-triazin-2-ol), were identified as the dominant triazine herbicides in groundwater samples from 51 loc...

trans- and cis-3-Chloroacrylic acid dehalogenase (CaaD and cis-CaaD, respectively) catalyze the hydrolytic dehalogenation of their respective isomers and represent key steps in the bacterial conversion of 1,3-dichloropropene to acetaldehyde. In prior work, a kinetic mechanism for the CaaD-cataly...

The isomeric mixture of cis- and trans-1,3-dichloropropene constitutes the active component of a widely used nematocide known as Telone II®. The mixture is processed by various soil bacteria to acetaldehyde through the 1,3-dichloropropene catabolic pathway. The pathway relies on an isomer-specif...

A Pseudomonas sp. UW4 protein (UniProt K9NIA5) of unknown function was identified as similar to 4-oxalocrotonate tautomerase (4-OT)-like and cis-3-chloroacrylic acid dehalogenase (cis-CaaD)-like subgroups of the tautomerase superfamily (TSF). This protein lacks only Tyr-103 of the amino acids cr...

Central CO2 chemoreceptors in poikilothermic vertebrates may not regulate ventilation at a particular pH setpoint; central chemoreceptor responses may more accurately reflect the relative charge state (alpha) of the imidazole of histidine. We have tested the alphastat hypothesis in the terrestri...

SummaryDiethyl pyrocarbonate, a compound extensively used as a nuclease inhibitor, reacts with low molecular weight RNA and forms products which are less precipitable with certain precipitating reagents than untreated RNA. This phenomenon, erroneously interpreted by Wiegers and Hilz (Biochem. Bi...

Diethyl pyrocarbonate (DEPC) in conditions that favour carbethoxylation of histidyl residues strongly inactivated E-type ATPase activity of a rat lung membrane preparation, as well as ecto-ATPase activity of rat vessels and human Epstein–Barr virus-transformed B lymphocytes. Inactivation of the...

A peritrich ciliate possesses a zooid and a long stalk consisting of a bundle of 3-nm-diameter filaments. Glycerinated stalks can contract in the presence of free Ca2+ and re-extend in the absence of free Ca2+. In the present study, we demonstrated that histidine residue(s) played a critical rol...

Tissue inhibitor of metalloproteinases-1 (TIMP-1) was treated with a range of chemical modification reagents in order to identify amino acid residues essential for inhibitory activity. Diethyl pyrocarbonate (DEPC) was found to be a potent inactivator at low reagent/TIMP molar concentrations. The...

The relationship of RNA, ribonuclease and diethylpyrocarbonate has been investigated using various concentrations of DEP, with and without the simultaneous addition of RNA.It has been found: 1.1. The presence of any considerable amount of RNA interferes with the inhibition of ribonuclease by die...