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 multid entate cyclic ligands complexed to rhenium is limited, some notable ex amples 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 p yridyl and bipyridyl ligands,(3.4) which is important because of the u sefulness of the phenylimido transition metal complexes as synthetic a nd catalytic intermediates.(5,6) Additionally, many nitrido and imido complexes of rhenium exhibit long-lived emissive electronic excited st ates, a feature which we hope to exploit in small molecule activation. (7) Consequently, we have examined the complexation of a phenylimidorh enium 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)