摘要:
Seven diiridium(II) complexes were synthesized by ligand substitution reactions of [Ir-2(mu-O2CMe)(2)Cl-2(CO)(2)] (1) and [Ir-2(mu-O2CMe)(2)Cl-2(CO)(2)(PY)(2)] (2). The reaction of 2 with the silver salt of a less coordinating anion, AgSbF6, gave a cationic complex [Ir-2(mu-O2CMe)(2)Cl(CO)(2)(py)(3)]SbF6 (3). A tricarbonyl cationic complex [Ir-2(mu-O2CMe)(2)(CO)(3)Cl(py)(2)]SbF6 (4) was obtained under a CO atmosphere. Complex 2 reacted with AgO2CCF3 to give [Ir-2(mu-O2CMe)(2)Cl(O2CCF3)(CO)(2)(py)(2)] (5) in toluene. [Ir-2(mu-hiq)(2)(CO)(2)Cl-2] (Hhiq = 1-hydroxyisoquinoline, 6) was synthesized by the bridging-ligand substitution of I with Hhiq. Its axial adducts [Ir-2(mu-hiq)(2)Cl-2(CO)(2)L-2] (L = Mepy (4-methylpyridine), 7 or PPh3, 8) were synthesized by addition of the ligands to a suspension of 6. In the structures of 7 and 8, two iridium atoms are bridged by two hiq ligands in a head-to-tail arrangement. The reaction of I with Hmhp (2-hydroxy-4-methylpyridine) led to triply bridged [Ir-2(mu-mhP)(3)(CO)(2)Cl(Hmhp)] (9). In complex 9, all the mhp ligands bridge between the Ir atoms in a head-to-head manner. The Ir-Ir distances of 3, 4, 5, 7 and 8 are 2.6047(7), 2.6216(9), 2.5899(9), 2.5933(5) and 2.634(2) A, respectively, which are similar to those observed in [Ir-2(mu-O2CMe)(2)Cl-2(CO)(2)L-2]. The Ir-Ir distance of 2.5512(4) angstrom in 9 is shorter than in the other complexes. (c) 2005 Elsevier B.V. All rights reserved.