Crystal structure of chlorido­(2-{[2-(4-chloro­phen­yl)hydrazin-1-yl­idene-κN1](phen­yl)meth­yl}pyridine-κN)(η5-penta­methyl­cyclo­penta­dien­yl)iridium(III) tetra­phenyl­borate. (March 2015)