AN ENVELOPED RHENIUM(V) PHENYLIMIDO COMPLEX OF 1,2-BIS(2,2'-BIPYRIDYL-6-YL)ETHANE (O-BPY)

Information concerning the structural and reaction chemistry of multidentate cyclic ligands complexed to rhenium is limited, some notable examples being trans-[Re(O)(2)(cyclam)](+ 1) and [Re(O)(L)(OMe)(2)]ClO4,(2) where L is 2,2':6',2'':6'',2''-quarterlyridine. Our recent efforts have focused on the chemistry of imidorhenium complexes with cyclic pyridyl and bipyridyl ligands,(3.4) which is important because of the usefulness of the phenylimido transition metal complexes as synthetic and catalytic intermediates.(5,6) Additionally, many nitrido and imido complexes of rhenium exhibit long-lived emissive electronic excited states, a feature which we hope to exploit in small molecule activation.(7) Consequently, we have examined the complexation of a phenylimidorhenium complex with the multidentate ligand 1,2-bis(2,2'-bipyridyl-6-yl)ethane (o-bpy),(8) and report here the synthesis and electrochemical and structural properties. From this and previous work, it is apparent that the o-bpy ligand is capable of stabilizing trans bpy geometries at metals as diverse as Re(V) and Ru(II).(9)