Structure and thermal properties of (1,1,1-trifluoro-4-methyliminopentanoato-2) (cyclooctadiene-1,5)iridium(I)

Resumo

A mixed-ligand iridium(I) complex with the imino-derivative of asymmetric β-diketone [Ir(cod)(Meitfac)] (cod = C₈H₁₂, cyclooctadiene-1,5; Mei-tfac = CF₃C(O)CHC(NMe)CH₃, 1,1,1-trifluoro-4-methyliminopentanoato-2) is synthesized for the first time. The compound is obtained by the interaction of [Ir(cod)Cl]₂ with sodium β-iminoketonate in diethyl ether in the inert atmosphere and is characterized by elemental analysis, IR and NMR spectroscopy. According to the single crystal X-ray diffraction analysis, the compound is a monomeric molecular complex. The coordination environment of iridium is a distorted square; the Ir–O and Ir–N bond lengths are 2.031(1) Å and 2.086(2) Å respectively; the average distance Ir–C′ = 1.994(8) Å (C′ is the center of the С=С bond of the cod ligand); the NIrO chelate angle is 91.30(6)°, and the C′IrC′ angle is 87.63°. The crystal packing contains dimers formed by weak F…H–C hydrogen interactions. The thermal properties of the complex are studied by thermogravimetry. The compound passes into the gas phase in the temperature range 150-260 °C (mass loss 93.5%) and is characterized by a lower volatility as compared with its β-diketonate analog [Ir(cod)(tfac)] (tfac = CF₃C(O)CHC(O)CH₃, 1,1,1-trifluoropentadionato-2,4).