Studies on an argon laser‐induced photopolymerization employing both mono‐ and bischromophoric hemicyanine dye—Borate complex as a photoinitiator. Part III

Abstract

Two series of homodimeric hemicyanine dyes based on 4-(p-N,N-dialkylaminostyryl)pyridinium and 4-(p-N,N-dialkylaminostyryl)quinolinium residues have been evaluated as novel photoinitiators for radical polymerization induced with an argon ion laser visible emission. In the tested photoredox pairs, hemicyanine dye cation acts as an electron acceptor and it is coupled with n-butyltriphenyl borate anion being an electron donor. The photochemistry of the series of bichromophoric stilbazolium borates, 1,3-, 1,5-, and 1,10-bis-[4-(p-N,N-dialkylaminostyryl)pyridinyl]alkane di-n-butyltriphenylborates and 1,3-, 1,5-, and 1,10-bis-[4-(p-N,N-dialkylaminostyryl) quinolinyl]alkane di-n-butyltriphenylborates, was compared with the photochemistry of the structurally related, monochromophoric styrylpyridinium and the styrylquinolinium borates. The experimental results indicated that the rate of photopolymerization depends on DG el of the electron transfer between borate anion and hemicyanine cation. The relationship between the rate of polymerization and the free energy of activation shows the dependence predicted by the classical theory of the electron transfer.

Red‐Light‐Induced Cationic Photopolymerization: Perylene Derivatives as Efficient Photoinitiators

“…being able to transform multifunctional monomers (acrylates or epoxides) and prepolymers into highly cross‐linked networks . Even though some successful PISs based on organic compounds and organometallic complexes have been proposed for visible‐light‐induced radical or cationic polymerizations and manufacture of photoresists, the challenge for the design of novel PISs still remains open especially those working at longer wavelength (>532 nm). To the best of our knowledge, several reports concern red light or near‐IR‐induced radical photopolymerization; however, for PISs that can work in cationic photopolymerization under red light, only violanthrone‐79‐based PISs were recently reported with good photoinitiating abilities under a laser diode at 635 nm .…”

Photopolymerization as a promising method to sense biorecognition events

“…Most authors apply cyclic voltammetry measurements to the reagents solutions (initiator and amine, respectively) [230][231][232][233][234][235][236]237 , while others employ an approximation related to adiabatic ionization potentials obtained as extrapolation in a photoelectron spectra measurement 221 .…”