Mixed-metal cluster chemistry V syntheses and X-ray crystal structure of Cp2Mo2Ir2(μ3-CO)(μ-CO)5(CO)4

Abstract

Abstract The mixed-metal cluster Cp 2 Mo 2 Ir 2 (CO) 10 has been synthesized by two procedures, namely reacting CpMo(CO) 3 H with IrCl(CO) 2 ( p -toluidine) under a CO atmosphere in the presence of zinc (23%), and by combining [CpMo(CO) 3 ] − with IrCl(CO) 2 ( p -toluidine) (78%). A structural study reveals that, in contrast to the analogous Cp 2 W 2 Ir 2 (CO) 10 , it is a rare example of a tetrahedral cluster with all edges bridged by CO, and that it possesses an unusual ‘semi-face-capping’ carbonyl ligand. Carbonyl bridging and hence steric crowding increase on proceeding from tungsten to molybdenum, rendering the title complex amongst the most crowded of metal clusters.