79128-88-4Relevant academic research and scientific papers
Photoinduced ω-bond dissociation of m-halomethylbenzophenones studied by laser photolysis techniques and DFT calculations. Substituted position effects
Yamaji, Minoru,Ogasawara, Michiyo,Kikuchi, Kazuhiro,Nakajima, Satoru,Tero-Kubota, Shozo,Marciniak, Bronislaw,Nozaki, Koichi
, p. 3268 - 3275 (2008/09/19)
Photochemical profiles of ω-cleavage of carbon-X (X = Br and Cl) bonds in m-bromo- and m-chloromethylbenzophenones (m-BMBP and m-CMBP) were investigated by laser photolysis techniques and DFT calculations. m-BMBP and m-CMBP were found to undergo ω-bond cleavage to yield the m-benzoylbenzyl radical (m-BBR) at 295 K, and the quantum yields were determined. No CIDEP signal was detected upon 308 nm laser photolysis of both the compounds. From these observations, it was inferred that the ω-bond of these m-halomethylbenzophenones (m-HMBP) cleaves in the lowest excited singlet state (S1(n,π*)) upon direct excitation. Upon triplet sensitization of acetone (Ac), the m-BBR formation was observed in transient absorption for an Ac-m-BMBP system, and an efficiency of the C-Br bond cleavage in the lowest triplet state (T1(n,π*)) of m-BMBP was determined. In contrast, formation of triplet m-CMBP was seen for an Ac-m-CMBP system. Absence of C-Cl bond cleavage in the triplet state of m-CMBP indicated the reactive state of m-CMBP for ω-cleavage is only the S 1(n,π*) state. Based on the efficiencies and DFT calculations for excited state energies, photoinduced ω-bond dissociation of m- and p-HMBPs was characterized. the Owner Societies.
Photoreactive benzoylphenylalanines and related peptides
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, (2008/06/13)
Provided is a benzoylphenylalanine of the formula: STR1 wherein STR2 is in the m or p position; and Pr is a protecting group which is easily cleavable in the presence of a peptide bond by a mild acid or base. This benzoylphenylalanine group is incorporated into a peptide chain which can be attached to a solid substrate having a reactive hydrogen by exposure to low energy ultraviolet light.
