Resumen: The reaction of Ir(SiNP)(cod)]PF6] (1]PF6]) and of IrCl(SiNP)(cod) (5) (SiNP = SiMe2{N(4-C6H4CH3)PPh2}2) with trimethyl phosphite affords the iridium(iii) derivatives of the formula IrHClx(SiNP-H){P(OMe)3}2-x](1-x)+ (x = 0, 3+; x = 1, 6) containing the ¿3C, P, P'-coordinated SiNP-H ligand (SiNP-H = Si(CH2)(CH3){N(4-C6H4CH3)PPh2}2). The thermally unstable pentacoordinated cation Ir(SiNP){P(OMe)3}(cod)]+ (2+) has been detected as an intermediate of the reaction and has been fully characterised in solution. Also, the mechanism of the C-H oxidative addition has been elucidated by DFT calculations showing that the square planar iridium(i) complexes of the formula IrClx(SiNP){P(OMe)3}2-x](1-x)+ (x = 0, 4+; x = 1, 7) should be firstly obtained from 2+ and finally should undergo the C-H oxidative addition to iridium(i) via a concerted intramolecular mechanism. The influence of the counterion of 2+ on the outcome of the C-H oxidative addition reaction has also been investigated. Idioma: Inglés DOI: 10.1039/c5dt02886h Año: 2015 Publicado en: Dalton Transactions 44, 42 (2015), 18596-18606 ISSN: 1477-9226 Factor impacto JCR: 4.177 (2015) Categ. JCR: CHEMISTRY, INORGANIC & NUCLEAR rank: 10 / 46 = 0.217 (2015) - Q1 - T1 Factor impacto SCIMAGO: 1.302 - Inorganic Chemistry (Q1)