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265 nm laser flash photolysis of some ortho-substituted anilides and related N-formylkynurenine derivatives

Journal Article:

Abstract

The physical and chemical properties of the triplet state of eight ortho-substituted anilides including N-formylkynurenine(FK), the major trp UV-photooxidation product and a remarkable photodynamic agent, have been investigated using both pulse radiolysis and 265 nm laser flash photolysis techniques. The molar extinction coefficient, the inter-system-crossing quantum yield and the oscillator strength of the T/sub 1/..-->..Tsub(n) absorption band (lambdasub(max)approximately equal 450nm) have been determined. It is shown that anilides having n..pi..* triplets readily react with most solvents whereas those having ..pi..,..pi..* triplets slowly react with alcohols. In both cases, the semi-reduced species are formed. In water, the formation of the semi-reduced species most probably involves the first excited singlet state. The triplet state properties of the FK derivatives (i.e. ortho-substituted anilides having a side chain bearing charged groups such as carboxylic or amino groups) are strongly modified by the ionization state of the charged side chain. In the case of the FK derivatives possessing an uncharged amino group, quenching of the triplet state occurs via a fast reversible electron transfer reaction from the NH/sub 2/ to the triplet anilide.
Authors:
Pileni, M P; Santus, R; [1]  Land, E J
  1. Museum National d'Histoire Naturelle, 75 - Paris (France)
Publication Date:
Jun 01, 1978
Product Type:
Journal Article
Reference Number:
AIX-10-448510; EDB-79-096124
Resource Relation:
Journal Name: Photochem. Photobiol.; (United Kingdom); Journal Volume: 27:6
Subject:
59 BASIC BIOLOGICAL SCIENCES; AMIDES; PHOTOLYSIS; KYNURENINE; ABSORPTION SPECTRA; CHEMICAL PROPERTIES; CHEMICAL REACTION KINETICS; ELECTRON BEAMS; EXCITED STATES; LASER RADIATION; PHYSICAL PROPERTIES; PULSED IRRADIATION; SENSITIZERS; SOLVENTS; TRIPLETS; ULTRAVIOLET RADIATION; AMINO ACIDS; BEAMS; CARBOXYLIC ACIDS; CHEMICAL REACTIONS; DECOMPOSITION; ELECTROMAGNETIC RADIATION; ENERGY LEVELS; IRRADIATION; KETO ACIDS; KINETICS; LEPTON BEAMS; MULTIPLETS; ORGANIC ACIDS; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; PARTICLE BEAMS; PHOTOCHEMICAL REACTIONS; RADIATIONS; REACTION KINETICS; REAGENTS; SPECTRA; 550200* - Biochemistry
OSTI ID:
6189440
Country of Origin:
United Kingdom
Language:
English
Other Identifying Numbers:
Journal ID: CODEN: PHCBA
Submitting Site:
INIS
Size:
Pages: 671-681
Announcement Date:

Journal Article:

Citation Formats

Pileni, M P, Santus, R, and Land, E J. 265 nm laser flash photolysis of some ortho-substituted anilides and related N-formylkynurenine derivatives. United Kingdom: N. p., 1978. Web.
Pileni, M P, Santus, R, & Land, E J. 265 nm laser flash photolysis of some ortho-substituted anilides and related N-formylkynurenine derivatives. United Kingdom.
Pileni, M P, Santus, R, and Land, E J. 1978. "265 nm laser flash photolysis of some ortho-substituted anilides and related N-formylkynurenine derivatives." United Kingdom.
@misc{etde_6189440,
title = {265 nm laser flash photolysis of some ortho-substituted anilides and related N-formylkynurenine derivatives}
author = {Pileni, M P, Santus, R, and Land, E J}
abstractNote = {The physical and chemical properties of the triplet state of eight ortho-substituted anilides including N-formylkynurenine(FK), the major trp UV-photooxidation product and a remarkable photodynamic agent, have been investigated using both pulse radiolysis and 265 nm laser flash photolysis techniques. The molar extinction coefficient, the inter-system-crossing quantum yield and the oscillator strength of the T/sub 1/..-->..Tsub(n) absorption band (lambdasub(max)approximately equal 450nm) have been determined. It is shown that anilides having n..pi..* triplets readily react with most solvents whereas those having ..pi..,..pi..* triplets slowly react with alcohols. In both cases, the semi-reduced species are formed. In water, the formation of the semi-reduced species most probably involves the first excited singlet state. The triplet state properties of the FK derivatives (i.e. ortho-substituted anilides having a side chain bearing charged groups such as carboxylic or amino groups) are strongly modified by the ionization state of the charged side chain. In the case of the FK derivatives possessing an uncharged amino group, quenching of the triplet state occurs via a fast reversible electron transfer reaction from the NH/sub 2/ to the triplet anilide.}
journal = {Photochem. Photobiol.; (United Kingdom)}
volume = {27:6}
journal type = {AC}
place = {United Kingdom}
year = {1978}
month = {Jun}
}