The reduction of the activated olefins dimethyl fumarate, cinnamonitrile, and fumaronitrile in tetra-n-butylammonium iodide-dimethylformamide solutions at a platinum electrode has been studied by rotating ring-disk electrode (RRDE) voltammetry, cyclic voltammetry, and coulometry. The results indicate that each compound undergoes a one-electron reduction to the anion radical which then undergoes a dimerization reaction. Rate constants for this dimerization reaction were found to be 110 (dimethyl fumarate), 880 (cinnamonitri]e), and 7 • l0 s (fumaronitrile) 1/mole-sec. Evidence of some bulk polymerization reaction was obtained from the coulometric results. * Electrochemical Society Active Member. ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 169.230.243.252 Downloaded on 2015-03-30 to IP

The electrochemical behaviour of the cis-trans-pairs : diethyl maleate (DEM), diethyl fumarate (DEF) and cis-and trans-dibenzoylethylene (CDBE and TDBE) in N,N-dimethylformamide solutions was investigated using cyclic and rotating ring-disc electrode (RRDE) voltammetry and bulk electrolysis. In both cases the cis-isomer is reduced at mme negative potentials than the trans-isomer. Although the radical anion formed from the trans-isomer is fairly stable, that of the cis-isomer undergoes a rapid isomerization to form the trans-radical anion and also reacts more rapidly in either self-or cross-coupling reactions. The electron spin resonance (e.s.r.) spectra obtained by electrolytic reduction of either DEM or DEF has been re-interpreted as being caused by different conformations of the trans-radical anion. Identical e.s.r. spectra are also obtained from reduction of CDBE and TDBE ; this is attributed to a single conformation of TDBE radical anion.

Digital simulation techniques have been employed to compute the steadystate currents at the rotating ring-disk electrode (RRDE) as functions of a rate parameter exhibiting explicit dependence on concentration of parent species (A) and rotation rate and also as functions of the flux at the disk for those cases in which the disk generated product (B) undergoes a following dimerization EC reaction (2B-~ products) or a second order ECE reaction (B ~-A-* C, where C may be electroactive at the disk potential) and nuances thereof. Diagnostic criteria are given for using RRDE results to distinguish among possible reaction mechanisms and working curves are provided to allow calculation of the rate constants of the homogeneous reactions.

The electrohydrodimerization reaction of dimethyl fumarate in the presence of cinnamonitrile and acrylonitrile was studied in dimethylformamide solution by rotating ring-disk emctrode, voltammetric and coulometric techniques. At potentials where only dimethyl fumarate is electroactive, the rate and mechanism of decay of the dimethyl fumarate anion radical are only slightly perturbed from the results obtained in the absence of cinnamonitrile and acrylonitrile. This is an indication that little or no cross-coupling was occurring. At potentials where both dimethyl fumarate and cinnamonitrile are electroactive evidence for the occurrence of a solution oxidation-reduction reaction consuming cinnamonitrile anion radical and dimethyl fumarate parent was obtained. In addition, the role of cis-trans isomerization of radical anions * Electrochemical Society Active Member.

SummaryPlasma levels of blood coagulation zymogens are lower in the newborn than in the adult, with the lowest levels being in preterm infants. It is not known if the lower coagulation factor levels reflect differences in synthesis, secretion or catabolism.Using a rabbit model we have compared prothrombin synthesis in the fetus and adult. In previous studies we attempted to compare transcription in the adult and fetal liver by extraction of mRNA, immobilization on a membrane and hybridization with a labeled cDNA for rabbit prothrombin. Comparison was impaired by the markedly dissimilar composition of fetal and adult rabbit liver; fetal liver is approximately fifty percent hematopoietic tissue even at term (1). In the present study, to obtain a more meaningful comparison we have employed in situ hybridization to compare directly prothrombin expression in adult and fetal liver. We report here that fetal liver contains more prothrombin mRNA than does adult liver. We have further compared prothrombin levels in protein extracts of adult and fetal liver and found that per microgram of extract, fetal liver contains as much prothrombin as does the adult. We conclude that the lower plasma prothrombin levels in the fetus do not reflect a lower rate of synthesis.