Dynamic Permutational Isomerism in a closo‐Cluster1. Issue 15 (29th February 2016) - Fu, Junhong
Abstract: Permutational isomers of trigonal bipyramidal [W2 RhIr2 (CO)9 ( η 5 ‐C5 H5 )2 ( η 5 ‐C5 HMe4 )] result from competitive capping of either a W2 Ir or a WIr2 face of the tetrahedral cluster [W2 Ir2 (CO)10 ( η 5 ‐C5 H5 )2 ] from its reaction with [Rh(CO)2 (η 5 ‐C5 HMe4 )]. The permutational isomers slowly interconvert in solution by a cluster metal vertex exchange that is proposed to proceed by Rh−Ir and Rh−W bond cleavage and reformation, and via the intermediacy of an edge‐bridged tetrahedral transition state. The permutational isomers display differing chemical and physical properties: replacement of CO by PPh3 occurs at one permutational isomer only, while the isomers display distinct optical power limiting behavior. Abstract : Cluster compounds : Permutational isomers [W2 RhIr2 (CO)9 ( η 5 ‐C5 H5 )2 ( η 5 ‐C5 HMe4 )] interconvert in solution by a cluster metal vertex exchange (see scheme); they display differing chemical and physical properties, replacement of CO by PPh3 occurring at one permutational isomer only, while the isomers display distinct optical power limiting behavior.