Oxidative addition of I2, MeI, and CH2I2 to the naphthalene-1,8-diamide bridged complex [Ir2{µ-1,8-(NH)2C10H6}(CO)2(PPh3)2]. X-Ray crystal structure of [Ir2I2(µ-CH2){µ-1,8-(NH)2C10H6}(CO)2(PPh3)2]·CH2Cl2

Abstract

Reaction of [Ir₂{µ-1,8-(NH)₂C₁₀H₆}(CO)₂(PPh₃)₂](1) with I₂, MeI, or CH₂I₂ at room temperature yields the dinuclear iridium(II) complexes [Ir₂I₂{µ-1,8-(NH)₂C₁₀H₆}(CO)₂(PPh₃)₂](2), [Ir₂Me(I){µ-1,8-(NH)₂C₁₀H₆}(CO)₂(PPh₃)₂](3), and [Ir₂(CH₂I)I{µ-1,8-(NH)₂C₁₀H₆}(CO)₂(PPh₃)₂](4) respectively. Complex (4) undergoes thermal oxidative isomerization to the methylene-bridged complex [Ir₂I₂(µ-CH₂){µ-1,8-(NH)₂C₁₀H₆}(CO)₂(PPh₃)₂](5). The molecular structure of (5) has been determined by an X-ray analysis. Crystals of (5) are monoclinic, space group P2₁/c, with a= 16.253(2), b= 12.214(1), c= 24.919(3)Å, β= 98.44(1)° and, Z= 4. The complex is dinuclear. The two distorted octahedral environments of the metal centres share an ideal common face formed by the three donor atoms of the bridging ligands. The co-ordination spheres are analogous, the geometric arrangement of the CO and PPh₃ ligands conferring a cis configuration to the molecule. The intermetallic Ir ⋯ Ir separation is 3.0306(4)Å.