Reactivity of hydridoirida-beta-diketones with bases: the selective formation of new di-mu-acyl-mu-hydridodiiridium(III) or dihydridoirida-beta-diketone complexes and heterometallic Ir(III)-Rh(I) derivatives.
The hydridoirida-beta-diketone [IrHCl{(PPh2(o-C6H4CO))2H}] (1a) reacts with bases such as KOH or NaHCO3 in methanol to undergo dehydrodechlorination and acyl-bridge formation affording [Ir2H2(PPh2(o-C6H4CO))2(mu-PPh2(o-C6H4CO))2] (2) with two acylphosphine chelate-bridging ligands, in a head-to-tail disposition, and terminal hydrides. The acyl bridges can be broken by pyridine, PPh3, CO or dimethylsulfoxide affording selectively mononuclear diacylhydrido neutral derivatives [IrH(PPh2(o-C6H4CO))2L] (3-6). la reacts with KOH or NaHCO3 in refluxing methanol to afford a novel dihydridoirida-beta-diketone [IrH2{(PPh2(o-C6H4CO))2H}](7), via dehydrodechlorination to afford 2, which then undergoes hydrogenation and protonation. The reaction of la with NEt3 affords 2 and [NHEt3]Cl. Further reaction affords [Ir2(mu-H){mu-PPh2(o-C6H4CO)}2(PPh2(o-C6H4CO))2] (8), with two acylphosphine chelate-bridging ligands and a bridging hydride. Neutral or cationic hydridoirida-beta-diketone complexes react with [Rh(cod)(OMe)]2 (cod = 1,5-cyclooctadiene) to afford hydridoirida-P-diketonaterhodium(I) complexes [IrHCl(mu-PPh2(o-C6H4CO))2Rh(cod)] (9) or [IrHL(mu-PPh2(o-C6H4CO))2Rh(cod)]ClO4 (L = py, 10; CO, 11), respectively that isomerise to the thermodynamically stable isomers of [IrCl(PPh2(o-C6H4CO))(mu-H))(mu-PPh,2(o-C6H4CO))Rh(cod)] (12) or [Ir(py)(PPh2(o-C6H4CO))(mu-H))(mu-PPh2(o-C6H4CO))Rh(cod)]ClO4(13). The reaction of 7 with [Rh(cod)(OMe)]2 affords [Ir(PPh2(o-C6H4CO))2(mu-H)2Rh(cod)](14). All the complexes were fully characterised spectroscopically. Single-crystal X-ray diffraction analysis was performed on 2, 4, 7, [8]ClO4 and 9.
Acha
Francisco
F
Facultad de Quimica de San Sebastián, Universidad del Pais Vasco, Apdo. 1072, 20080 San Sebastián, Spain.
Ciganda
Roberto
R
Garralda
María A
MA
Hernández
Ricardo
R
Ibarlucea
Lourdes
L
Pinilla
Elena
E
Rosario Torres
M
M