Reactions of Hydridoirida-尾-diketones with Amines or with 2-Aminopyridines: Formation of Hydridoirida-尾-ketoimines, PCN Terdentate Ligands, and Acyl Decarbonylation
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- 作者：Roberto Ciganda ; Mar铆a A. Garralda ; Lourdes Ibarlucea ; Claudio Mendicute-Fierro ; M. Carmen Torralba ; M. Rosario Torres
- 刊名：Inorganic Chemistry
- 出版年：2012
- 出版时间：February 6, 2012
- 年：2012
- 卷：51
- 期：3
- 页码：1760-1768
- 全文大小：592K
- 年卷期：v.51,no.3(February 6, 2012)
- ISSN：1520-510X
文摘
The hydridoirida-尾-diketone [IrHCl{(PPh2(o-C6H4CO))2H}] (1) reacts with benzylamine (C6H5CH2NH2) to give the hydridoirida-尾-ketoimine [IrHCl{(PPh2(o-C6H4CO))(PPh2(o-C6H4CNCH2C6H5))H}] (2), stabilized by an intramolecular hydrogen bond. 2 reacts with water to undergo hydrolysis and amine coordination giving hydridodiacylamino [IrH(PPh2(o-C6H4CO))2(C6H5CH2NH2)] (3). Cyclohexylamine or dimethylamine lead to hydridodiacylamino [IrH(PPh2(o-C6H4CO))2L] (4鈥?b>5). In chlorinated solvents hydridodiacylamino complexes undergo exchange of hydride by chloride to afford [IrCl(PPh2(o-C6H4CO))2L] (6鈥?b>9). The reaction of 1 with hydrazine (H2NNH2) gives hydridoirida-尾-ketoimine [IrHCl{(PPh2(o-C6H4CO))(PPh2(o-C6H4CNNH2))H}] (10), fluxional in solution with values for 螖H of 2.5 卤 0.3 kcal mol鈥? and for 螖S of 鈭?2.9 卤 3 eu. A hydrolysis/imination sequence can be responsible for fluxionality. 2-Aminopyridines (RHNC5H3R鈥睳) react with 1 to afford cis-[IrCl(PPh2(o-C6H4CO))(PPh2(o-C6H4CHNRC5H3R鈥睳))] (R = R鈥?= H (11), R = CH3, R鈥?= H (12), R = H, R鈥?= CH3 (13)) containing new terdentate PCN ligands in a facial disposition and cis phosphorus atoms as kinetic products. The formation of 11鈥?b>13 requires imination of the hydroxycarbene moiety of 1, coordination of the nitrogen atom of pyridine to iridium, and iridium to carbon hydrogen transfer. In refluxing methanol, complexes 11鈥?b>13 isomerize to afford the thermodynamic products 14鈥?b>16 with trans phosphorus atoms. Chloride abstraction from complexes [IrCl(PPh2(o-C6H4CO))(PPh2(o-C6H4CHNRC5H4N))] (R = H or CH3) leads to decarbonylation of the acylphosphine chelating group to afford cationic complexes [Ir(CO)(PPh2(o-C6H4))(PPh2(o-C6H4CHNRC5H4N))]A, 17 (R = H, A = ClO4) and 18 (R = CH3, A = BF4) as a cis/trans = 4:1 mixture of isomers. Single crystal X-ray diffraction analysis was performed on 6, 9, 13, and 14.