Reactions of Ph2SNH 1 with copper(II) halides in a 2:1 ratio is fast and
efficiently generates species of the type trans-Cu(Ph2SNH)X2. A significant
aspect of their coordination geometry comes with the observation that two
distinct isomers (or allogons) of the chloro complex can be generated and we
believe this is the first example of square-planar/pseudo-tetrahedral isomerism
in a neutral copper(II) complex. True polymorphism is displayed by these
allogons as they can be used to generate each other by crystallisation from the
appropriate solvent mixtures. No such isomerism is exhibited by the bromo
analogue. [Continues.
