I-127 MOSSBAUER-SPECTRA OF DIPHENYLIODONIUM HALIDES

The I-127 Mossbauer spectra have been obtained at 20 K for the dipheny liodonium halides, Ph2IX (X = Cl, Br) and their derivatives, (p-R-C6H4 ) IPhBr (R=CH3, CH30, Cl, COOH and N02). The valence electron populati ons of iodine are determined by the interactions with carbon atoms but not with bridging halogen atoms. The iodine-carbon bonds, having larg e p-character, are affected scarcely by the substituents at the para-p osition of the phenyl group. The large eta values for those compounds are explained in terms of a lone pair electrons on iodine(III) atoms.