[1,3-Bis(2,6-diiso-propyl-phen-yl)-1,3-di-hydro-2 H -imidazol-2-yl-idene]tri-iodo-borane benzene hemisolvate.

In the title hemisolvate, C 27 H 36 BI 3 N 2 . 0.5C 6 H 6 , the dihedral angles between the central heterocyclic ring and pendant benzene rings are 82.9 (8) and 88.7 (9)° and the complete benzene solvent mol-ecule of crystallization is generated by a crystallographic centre of inversion. In the crystal, one very weak C-H⋯I inter-action links the mol-ecules into [001] chains.