25753-12-2

Upstream product

• 103-45-7 acetic acid phenethyl ester 
• 67-56-1 methanol 
• 460062-23-1 tert-butyl 4-(4'-chloromethylbenzoyl)perbenzoate 
• 88641-79-6 tert-butyl 4-(4'-bromomethylbenzoyl)perbenzoate 

Downstream Products

• 79849-46-0 4-(2-(tetrahydropyran-2-yloxy)ethyl)bromobenzene 

Relevant academic research and scientific papers

Triplet energy distribution in photoinitiators containing two dissociable groups

Suitable probe molecules containing the benzophenone chromophore and one dissociable bond [perester 1 or C-X (4, 5)] or two such bonds (2, 3) have been synthesized and studied to examine intramolecular triplet energy dispersion. Triplet energies and phosphorescence quantum yields as well as quantum efficiencies of bond scissions have been studied, and the flow of triplet energy in such molecules is discussed. Upon irradiation at 350 nm in either benzene or methanol, the target peresters undergo dissociation of both cleavable groups, producing a pair of radicals. The presence of a benzylic chloride function has little influence on the efficiency of perester dissociation. However, the presence of a benzylic bromide function was found to decrease the quantum yield of decomposition of the perester function of 3. This can be explained by taking into account the effect of the heavy atom and the rate of cage geminate radical pair recombination. The nature of the heavy atom perturbation, however, was found to be different in 5 as compared with 3.

Photoinitiators for photopolymerization of unsaturated systems

Compounds of the general formula I STR1 wherein Z is CR1 R2 (OR3) or phenyl, R1 being H, C1-6 -alkyl or phenyl, R2 being H, C1-6 -alkyl or C1-6 -alkoxy and R3 being H, C1-6 -alkyl or C1-6 -alkanoyl and Z' is Y--[(CH2)m --X]n --, X being CH2 or 0, Y being OH; COOH or SO3 H including the alkali metal, alkaline earth metal or ammonium salts thereof and also the salts thereof with organic nitrogen bases; or NRR' in which R and R' are in each case H, C1-20 -alkyl or C1-4 -hydroxyalkyl, if appropriate quaternized or in the form of the acid addition salts, and n and m each being the numbers 1-4, are excellently suitable as photoinitiators for the photopolymerization of ethylenically unsaturated compounds, in particular in aqueous systems.