Short communication. Structural studies of bromine adducts of 1,2‐ and 1,4‐bis(phenylseleno)benzenes. Evidence for the (TB, MC) structure of 1,2‐(PhSeBr2)2C6H4

Abstract

Abstract1,2‐Bis(phenylseleno)benzene reacted with equimolar amount of bromine to yield a trigonal bipyramidal (TB) adduct, in contrast to the molecular complex (MC) structure of selenanthrene with bromine. Whereas the structure of 1,4‐(PhSeBr2)2C6H4 was (TB, TB) at the two selenium atoms, that of the 1,2‐derivative was demonstrated to be (TB, MC), the first example of an MC structure of PhSeC6H4Y with Br2 [Y = 2‐PhBr2Se(TB)]. Both electronic and steric effects of the group must play an important role in MC formation. Rapid structural exchange in this tetrabromide, (TB, MC) ⇄ (MC, TB), was also observed.