Addition of Water Across Si-Ir Bonds in Iridium Complexes with kappa-P,P,Si (biPSi) Pincer Ligands

作者：Garcia Camprubi Alba; Martin Marta; Sola Eduardo^*

来源：Inorganic Chemistry, 2010, 49(22): 10649-10657.

DOI：10.1021/ic1016774

Electrophiles such as Me(+) Ag(+), or protons react with the five-coordinate Ir(III) complex [IrClH(biPSi)] (biPSi = kappa-P,P, Si-Si(Me){(CH(2))(3)PPh(2)}(2)) by abstracting its chloride ligand. The resulting species can be stabilized by a variety of L ligands to give the cationic complexes [IrH(biPSi)L(2)](+). The derivative [IrH(biPSi)(NCMe)(2)](+) has been subjected to a kinetic study regarding the facile dissociations of its acetonitrile ligands. The presence of water changes the course of the reaction producing dihydride complexes that contain the silanol ligand kappa-O, P,P-HOSi(Me){(CH(2))(3)PPh(2)}(2) (biPSiOH). The water activation product [IrH(2)(biPSiOH)(NCMe)](CF(3)SO(3)) undergoes insertion reactions with ethylene and phenylacetylene. The use of hydrolyzable fluorinated counterions such as PF(6)(-) or BF(4)(-) further modifies the reaction by provoking the incorporation of fluoride at the silicon atom of the former biPSi ligand. The dihydride resulting after such a process, [IrH(2)(biPSiF)(NCMe)]BF(4) (biPSiF = kappa-P(2)-FSi(Me){(CH(2))(3)PPh(2)}(2)), displays a trans-chelating diphosphine ligand. When dehydrogenating the Ir center, spontaneously or using ethylene as hydrogen acceptor, the diphosphine backbone undergoes a Si-C bond cleavage leading to a new Ir(III) species with kappa-P,Si and kappa-C,P chelate ligands.

• 出版日期2010-11-15