New hydridoirida-beta-diketones derived from 8-quinoline-carbaldehyde and o-(diphenylphosphino)benzaldehyde.
8-Quinoline-carbaldehyde (C(9)H(6)NCHO) reacts in methanol with [IrCl(Cod)](2) (Cod = 1,5-cyclooctadiene) to give the acylhydrido complex [IrHCl(C(9)H(6)NCO)(Cod)] (1) or with [IrHCl{PPh(2)(o-C(6)H(4)CO)}(Cod)] to afford the hydridoirida-beta-diketone complex [IrHCl({PPh(2)(o-C(6)H(4)CO)}(C(9)H(6)NCO)H)] (2). Complex 2 reacts with silver perchlorate in the presence of pyridine to afford the cationic [IrH({PPh(2)(o-C(6)H(4)CO)}(C(9)H(6)NCO)H)(py)]ClO(4) (), which in solution transforms slowly into the cationic dinuclear complex [Ir{micro-PPh(2)(o-C(6)H(4)CO)}(C(9)H(6)NCO)(py)](2)(ClO(4))(2) (4) with two acylphosphine chelate-bridging ligands. The reaction of 2 with AgClO(4) in the presence of carbon monoxide affords [IrH({PPh(2)(o-C(6)H(4)CO)}(C(9)H(6)NCO)H)(CO)]ClO(4) (5), which in solution is in equilibrium with the deprotonated diacylhydrido complex [IrH{PPh(2)(o-C(6)H(4)CO)}(C(9)H(6)NCO)(CO)] (6). The reaction of 2 with Et(3)OPF(6) results in the formation of [[IrH({PPh(2)(o-C(6)H(4)CO)}(C(9)H(6)NCO)H)](2)(micro-Cl)]PF(6) (7), containing a cationic dinuclear species with a single chlorine atom bridging two hydridoirida-beta-diketone fragments. The reaction of with [Rh(OMe)(Cod)](2) affords the hydridoirida-beta-diketonaterhodium(I) complex [IrHCl{micro-PPh(2)(o-C(6)H(4)CO)}(micro-C(9)H(6)NCO)Rh(Cod)] (8), which isomerizes to the thermodynamically stable isomer [IrCl{PPh(2)(o-C(6)H(4)CO)}(micro-H)(micro-C(9)H(6)NCO)Rh(Cod)] (9). The catalytic activity of these complexes in the hydrogen transfer from isopropanol to cyclohexanone has been tested. The X-ray diffraction structures of complexes 2, 4 and 9 are reported.
Ciganda
Roberto
R
Facultad de Química de San Sebastián, Universidad del País Vasco, Apdo. 1072, 20080, San Sebastián, Spain.
Garralda
María A
MA
Ibarlucea
Lourdes
L
Pinilla
Elena
E
Torres
M Rosario
MR