C–H Activation of the 5‐(Pyridine‐3‐yloxy)isophthalic Acid to Construct Iridium, Rhodium, and Ruthenium Binuclear Metallocyclophanes

Abstract

The multitopic ligand, 5-(pyridine-3-yloxy)isophthalic acid (m-POiPH 2 , 1), containing two different coordination sites of pyridine and isophthalic acid linked by the C-O-C bond, is prepared. The reaction of 1 with half sandwich complexes of [Cp*Rh(OAc) 2 ] (Cp* = η 5 -C 5 Me 5 ), [Cp*Ir(OAc) 2 ], and [(p-cymene) Ru(OAc) 2 afford the construction of binuclear metallocyclophanes [(Cp*Ir) 2 (m-POiP) 2 ] (2), [(Cp*Rh) 2 (m-POiP) 2 (3), and [((p-cymene)Ru) 2 (m-POiP) 2 ] (4) in high yields. Crystal structures of 2, 3, and 4 illustrate binuclear metallocyclophanes constructed by cyclometallation by ortho-C-H activation and coordination of N-donor with metals which is confirmed by a single crystal X-ray diffraction (SC-XRD). Each metallocyclophanes shows unique packing structure by intermolecular hydrogen bonding; 2 and 3 shows 1D linear chain network, while the packing of 4 presents the 2D sheet.