1. Acyliridium(III) Complexes with PCN Terdentate Ligands Including Imino‐ or Iminium‐Acyl Moieties or Formation of Hydrido from Hydroxyl
- Author
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María A. Garralda, José M. Seco, Itziar Zumeta, Claudio Mendicute-Fierro, and Antonio Rodríguez-Diéguez
- Subjects
010405 organic chemistry ,Ligand ,Hydrogen bond ,chemistry.chemical_element ,Iminium ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,0104 chemical sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Intramolecular force ,Pyridine ,Organic chemistry ,Moiety ,Iridium ,Isomerization - Abstract
2-Aminoalkylpyridines [H2N(CH2)nC5H4N] (n = 1 or 2) react with [IrHCl{(PPh2(o-C6H4CO))2H}] (1a) in THF to afford hydridoirida-β-ketoimines [IrHCl{(PPh2(o-C6H4CO))(PPh2(o-C6H4CN(CH2)nC5H4N))H}] (2, n = 1; 3, n = 2) with intramolecular N-H···O hydrogen bonding and a dangling pyridine. In protic media 2–3 transform into [IrH(PPh2(o-C6H4CO))(PPh2(o-C6H4C=N(CH2)nC5H4N))] (4, n = 1; 5, n = 2) containing new terdentate PCN ligands in a facial disposition with the phosphorus atom trans to H and an iminoacyl fragment trans to the other phosphorus atom. The formation of 4–5 requires breaking of the hydrogen bond, isomerization, and dehydrochlorination of an intermediate iminium-acyl species to allow the coordination of the nitrogen atom of pyridine to iridium. The reaction of 1a with the N-substituted N-methylaminomethylpyridine allows the synthesis of [IrH(PPh2(o-C6H4CO))(PPh2(o-C6H4C=N(CH3)CH2C5H4N))]ClO4 (6) containing a PCN ligand with an iminium-acyl moiety trans to phosphorus. The reaction of [IrH2{(PPh2(o-C6H4CO))2H}] (1b) with 2-(aminoalkyl)pyridines [H2N(CH2)nC5H4N] (n = 1 or 2) in MeOH requires the presence of KOH to afford the hydrido derivatives [IrH(PPh2(o-C6H4CO))2(NH2(CH2)nC5H4N,κNH2)] (7, n = 1; 8, n = 2) were the ligands are amino-coordinated with a dangling pyridine. The reaction occurs with hydrogen evolution and transfer of hydrogen from a hydroxyl in the solvent to iridium. Single-crystal X-ray diffraction analysis was performed on 3, 4, 6, and 8.
- Published
- 2016