Co-ordination chemistry of sulfimides

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.]