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Radical reactions in the co‐ordination sphere of transition metals. X —radicals derived from 4,4‐biphenyldiols, 4,4′‐thiobisphenols and bis(4‐hydroxybenzyl)sulphide
Author(s) -
Tkáč A.,
Omelka L.,
Jiráčková L.,
Pospíšil J.
Publication year - 1980
Publication title -
organic magnetic resonance
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0030-4921
DOI - 10.1002/mrc.1270140406
Subject(s) - radical , chemistry , cobalt , steric effects , sulfur , transition metal , electron transfer , photochemistry , crystallography , coordination sphere , inorganic chemistry , stereochemistry , organic chemistry , crystal structure , catalysis
Using the analysis of the splitting constants of the ESR spectra, factor are described which affect the stability of free phenoxyls and of phenoxyls co‐ordinated on cobalt, generated by the reaction of tert ‐butyleperoxyls and 4,4′‐biphenyldiols (1), 4,4′–thiobisphenols (2 and 5), 4,4′‐dithiobisphenol 3a, the 4,4′‐trithiobisphenol 3b, di(3,5‐di‐ tert ‐butyl‐4‐hydroxybenzyl) sulphide (4a) and its corresponding sulphoné (4b). Phenoxy radicals are formed from compounds of type 1–4 in the presence and in the absence of oxygen. In the case of generation with oxygem complexed to cobalt, compounds 4, for steric reasons, form co‐ordinated radicals of the cyclohexadienonyloxyl type. Free phenoxyls are also formed from 2a–2c, 3a and 3b as a result of the direct transfer of electrons from the sulphur non‐bonding electron pair to the peroxidic bond of tert ‐butyl hydroperoxide in the absence of cobalt.