π-Effects in thioether macrocyclic complexes: the stabilisation and structure of the low-spin FeIII thioether complex [Fe([9]aneS3)2]3+
Abstract
Oxidation of [Fe([9]aneS3)2]2+ to [Fe([9]aneS3)2]3+ leads to an elongation of the Fe–S bonds from 2.251 (1), 2.241(1), 2.259(1)Å in the 2+ cation to 2.280(3), 2.2846(25), 2.276(25)Å in the 3+ cation giving, for the first time, direct structural evidence for the π-acceptor properties of thioether crowns.