METAL-OLEFIN BONDING - PREPARATIONS, SPECTRA, AND X-RAY STRUCTURES OF CHLORO-1, 6-BIS(DIPHENYLPHOSPHINO)-TRANS-HEX-3-ENEIRIDIUM(I), IRCL[PH2P(CH2)2CH=CH(CH2)2PPH2] AND CHLORO-1, 6-BIS(DIPHENYLPHOSPHINO)-TRANS-HEX-3-ENEDIHYDRIDOIRIDIUM(III), IRH2CL[PH2P(CH2)2CH=CH(CH2)2PPH2]

Title full:Metal-olefin bonding. Preparations, spectra, and x-ray structures of chloro-1,6-bis (diphenylphosphino)-trans-hex-3-eneiridium(I), IrCl [(Ph2P(CH2)2CHCH(CH2) 2PPh2], and chloro-1,6-bis(diphenylphosphino)-trans-hex-3-enedihydridoiridium(III), IrH2Cl(Ph2P(CH2)2CHCH (CH2)2PPh2]. The 13C NMR spectrum and X-ray structure of IrCl[Ph2P(CH2)2CHCH(CH2) 2PPh2], and the preparation, 1H and 13C NMR spectra, and X-ray structure of IrH2Cl[Ph2P(CH2)2CHCH(CH 2)2PPh2] are described. Crystals of the former are monoclinic, a = 13.039(4), b = 13.601(4), c = 16.944(5) Å, β = 119.68(5) °, Z = 4, space group Cc. Block diagonal least squares refinement has returned the residual, R, as 0.026 for 2193 observed reflections. The complex is monomeric with square planar inner coordination. Bonds to Ir are IrCl, 2.391(2); IrP, 2.296(2), 2.272(2); IrC, 2.092(9), 2.084(9) Å. Crystals of the latter are monoclinic, a= 10.28(1), b = 19.066(2), c = 15.072(4) Å, β = 92.17(10) °, Z = 4, space group P21/c. Full matrix refinement has returned R as 0.054 for 2327 observed reflections. This monomeric complex has octahedral metal coordination. Bonds to Ir are IrCl, 2.510(5); IrP, 2.301, 2.283(4); IrC, 2.343, 2.284(18) Å. The geometry of the olefin implies absence of metal-π{black star} back-bonding. © 1979.