781639-08-5Relevant academic research and scientific papers
Synthesis and reactivity of iridium complexes with pyridine and piperidine ligands: Models for hydrodenitrogenation
Rosales, Merlin,Gonzalez, Teresa,Atencio, Reinaldo,Sanchez-Delgado, Roberto A.
, p. 2952 - 2956 (2007/10/03)
The complexes [Ir(H)2(η1-N-L) 2(PPh3)2]PF6, L = py (1), iQ (2) and pip (3) (py = pyridine, iQ = isoquinoline, pip = piperidine) have been synthesized in high yields by hydrogenation of [Ir(cod)(PPh3) 2]PF6 in the presence of the appropriate nitrogen compound. When hydrogen is bubbled through 1,2-dichloroethane solutions of 1 or, two new species were formed in each case by C-Cl bond activation of the solvent, ηIr(H)2Cl(η1-N-L)(PPh3) 2 (L = py, 4; iQ, 5) and IrH(Cl)2( 1-N-L)(PPh3)2 (L = py, 6; iQ, 7). Reaction of 3 with py or iQ yielded complexes 1 and 2, respectively, while under a slow stream of carbon monoxide the complex [Ir(H)2(η 1-N-pip)(CO)(PPh3)2]PF6 (8) was produced. Complex 3 also reacts with halide and 4-bromothiophenolate anions leading to the corresponding neutral species Ir(H)2(X)(η 1-N-pip)(PPh3)2, X = Cl (9), I (10) and 4-BrC6H4S (11), or with [MoS4]2- to yield the hetero-bimetallic complex [Ir(H)(PPh3) 2(μ-S)2MoS2]- (13). All the new complexes were characterized by analytical and spectroscopic methods. The X-ray structures of 1, 2 and 8 consist of distorted octahedra with a mutually cis disposition of the two hydrides and mutually trans phosphines. Complexes 1, 2 and 3 and their derivatives are of interest as models for the chemisorption step in hydrodenitrogenation reactions on solid catalysts.
