290307-62-9Relevant academic research and scientific papers
Rhodium, iridium and gold complexes of the short-bite ligand 1-benzyl-2-imidazolyldiphenylphosphine
Tejel, Cristina,Ciriano, Miguel A.,Bravi, Rita,Oro, Luis A.,Graiff, Claudia,Galassi, Rossana,Burini, Alfredo
, p. 129 - 136 (2003)
Reactions of [{M(μ-Cl)(cod)}2] (M=Rh, Ir) with 1-benzyl-2-imidazolyldiphenylphosphine gave the mononuclear P-bonded compounds [MCl(cod)(Ph2PBzIm)]. They react with [M(cod)(acetone)x]BF4 to give the cationic [{M(cod)}2(μ-Cl)(μ-Ph2PBzIm)]+ complexes, while they react with silver salts to give the homometallic dinuclear complexes HT-[{M(μ-Ph2PBzIm)(cod)}2](BF4) 2 (M=Rh, Ir) containing two mutually cis bridging ligands in a HT disposition. Addition of [AuCl(tht)] to [MCl(cod)(Ph2PBzIm)] gave the heterometallic complexes [MCl(cod)(μ-Ph2PBzIm)AuCl] with the gold atom coordinated to the P-end. While the Ir-Au compound remained as such in solution, the Rh-Au complex was found to be in equilibrium with [AuCl(Ph2PBzIm)] and [{Rh(μ-Cl)(cod)}2]. Reaction of trans-[RhCl(CO)(Ph2PBzIm)2] with [{Rh(μ-Cl)(CO)2}2] gave the 'A-frame' complex [{RhCl}2(μ-CO)(μ-Ph2PBzIm)2] while the reaction with [PdCl2(NCMe)2] resulted in the formation of three isomers of the metal-metal bonded compound [(CO)Cl2Rh(μ-Ph2PBzIm)2PdCl].
Reversible C-H bond activation of a bifunctional phosphine bridging ligand across two unbonded metal centers
Tejel, Cristina,Bravi, Rita,Ciriano, Miguel A.,Oro, Luis A.,Bordonaba, Marta,Graiff, Claudia,Tiripicchio, Antonio,Burini, Alfrede
, p. 3115 - 3119 (2008/10/08)
Reaction of [{Ir(μ-Cl)(cod)}2] with the short-bite bifunctional N,P-donor ligand (1-benzyl-2-imidazolyl) diphenylphosphine (Ph2PBzIm) gives the yellow complex [IrCl (Ph2PBzIm)(cod)] (2). A further addition of [{Ir (μ-Cl)(cod)}2] to 2 results in the reversible metalation of a phenyl ring across two unbonded iridium centers to give orange crystals of [IrCl(cod){μ-PPh(C6H4)-BzIm}IrHCl (cod)] (1). Complex 1 is in equilibrium with the mononuclear complex [IrCl(Ph2-PBzIm)(cod)] and the active species undergoing the sp2-C-H activation, [{IrCl(cod)}2 (μ-Ph2PBZIm)], in solution. Abstraction of one chloride ligand from 1 with AgBF4 produces the deinsertion of the C-H bond yielding the cationic complex [{Ir(cod)}2(μ-Ph2 PBzIm)(μ-Cl)]-BF4, which regenerates 1 upon addition of a chloride-soluble salt. The cationic complex [{Ir- (cod)}2(μ-Ph2PBzIm)(μ-Cl)]BF4 is inactive for the above-mentioned sp2-C-H bond activation and can be prepared alternatively from the reaction of 2 with [Ir(cod) (CH3CN)2]BF4. A related binuclear sp2-C-H bond activation across two unbonded metals also occurs in the reaction of dppm with [{Ir(μ-Cl)(cod)}2] in a 1:1 molar ratio. This reaction leads to a mixture in equilibrium of [{IrCl(cod)}2(μ-dppm)] and the hydride complex [IrCl(cod){μ-PPh(C6H4)CH2-PPh2)}IrHCl (cod)] in a 1.5:1 molar ratio, respectively, in dichloromethane at 20°C. The structure of the mixed-valence complex 1 was solved by X-ray diffraction studies.
