Iridium complexes with 2,1,3-benzothiadiazole and related ligands

The reaction of [IrCp*Cl(mu-Cl)](2) (5) with 2,1,3-benzothiadiazole (1) in a 1:1 ratio gives the binuclear complex [Ir2Cp*Cl-2(4)(mu, eta(2)-1)] (6) where 1 acts as a bridging ligand. The 4-XH derivatives of 1 (2, X = O; 3, X = NH) interacted with 5 in various ways. Under basic conditions, 2 and 5 form chelate complexes [IrCp*CIL] (7) (L = C6H3ON2S) (isolated in the form of a co-crystal with the initial 2 and in the individual form, in both cases with solvated toluene) or [Ir2Cp*Cl-2(3)(mu, eta(3)-L)] (8) in the 4:1, 2:1 or 1:1 reactions, respectively. Derivative 3, even with an excess of 5, affords only the mononuclear complex [IrCp*Cl-2(3)] (9) where 3 acts as a monodentate ligand, bonded to the Ir center by the ring N atom. A similar complex, [IrCp*Cl-2(4)] (10), was also obtained from 5 and acenaphtho[1,2-c][1,2,5]thiadiazole (4) in excess of the former reagent. The structures of complexes 6-10 were confirmed by single-crystal X-ray diffraction. (c) 2012 Elsevier Ltd. All rights reserved.