Deaminatively generated carbocations as initiators of styrene polymerization.

[reaction: see text] Addition polymerization is readily accomplished via free radicals and carbanions but conventional initiations via carbocations are limited principally by low initiator reactivity. Thermolyses of N-nitrosamides produce nitrogen-separated ion-pairs (NSIPs) containing exceedingly reactive carbocations. We report here the novel use of this facile mode of carbocation generation in the polymerization of styrene.

The mechanism of enzymically induced chemiluminescence reactions of lucigenin.

Lucigenin (Bis-N-methylacrylium nitrate) reacts with H2O2 to produce ground state and excited state monomer. The excited state monomer decays with the emission of light. When lucigenin is added to reaction mixtures containing vitamin-K-dependent carboxylase, light emission is produced which is inversely proportional to enzyme concentration and co-inhibited with inhibitors of vitamin-K-dependent carboxylase.

Vitamin K-dependent carboxylase: evidence for a semiquinone radical intermediate.

Nanosecond laser flash photolysis has been used to produce and identify the vitamin K semiquinone (radical) from vitamin K dihydroquinone and to observe its formation and decay in the presence of vitamin K-dependent carboxylase (epoxidase). The activity of vitamin K-dependent carboxylase is not decreased by exposure to the laser. Absorbance of the semiquinone is proportional to enzyme concentration and is stimulated by a synthetic substrate, Phe-Leu-Glu-Glu-Ile.