SOLID-STATE AND SOLUTION FT-RAMAN SPECTRA OF THE TETRAIODINE DICATIONI-4(2- IMPLICATIONS FOR THE CLAIMED EXISTENCE OF I+ SO2 SOLUTION() )

I-4(2+) is the only known cyclic homopolyatomic cation or anion of iod ine. It has a rectangular planar structure which may be thought of as containing two I-2(+) units joined by a weak pi-pi* 4 centre 2 electr on bond.(1) In this paper we report our FT-Raman spectra of I-4(2+), w hich conflict with those published by Gillespie et al.,(1) and present evidence that the peaks attributed to a species containing iodine in the +1 oxidation state are in fact due to I-4(2+).