Electron-transfer reactions in cyanine borate ion pairs: photopolymerization initiators sensitive to visible light

Abstract

In summary, the results presented here demonstrate the remarkable catalytic effect that one-electron oxidation can have on the rearrangement of vinylcyclopropanes to cyclopentenes. Acknowledgment.

Difluoroboranyl derivatives as efficient panchromatic photoinitiators in radical polymerization reactions

“…This observation shows that the light intensity has no effect on the quantum yield of free radical formation / [41] and suggests that the polymerization follows a typical radical chain mechanism with second-order termination [35]. It is well-known that the alkyl radical formed from borate salts as a results of the electron transfer from borate anion to the excited state of sensitizer leading to boranyl radical followed by its decomposition initiates radical polymerization of acrylates [42,43]. To study the photochemical process that occurs in the excited state of the difluoroboranyl complexes, the nanosecond laser flash photolysis was used.…”

The Comparison of the Photoinitiating Ability of the Dyeing Photoinitiating Systems Acting via Photoreducible or Parallel Series Mechanism

“…The work of Schuster and co-workers [19,20] on the photochemistry of cyanine borates led to the preparation of the color-tunable, operating in the visible region commercial photoinitiators [21]. This research group discovered that, photolysis of 1,4-dicyanonaphthalene containing an alkyltriphenylborate leads to one electron oxidation of alkyltriphenylborate salts yielding an alkyltriphenylboranyl radical that undergoes carbonboron bond cleavage and the formation of free radicals [22].…”

Photoinitiated polymerisation of monolithic stationary phases in polyimide coated capillaries using visible region LEDs

“…Efficient single electron transfer from the borate anion to the excited cyanine sensitiser is known to generate the cyanine radical and the butyl radical, along with phenyl borane [13][14][15] . The butyl radical species are then able to initiate chain 5 polymerisation.…”