Phosphine complexes infrared spectra

The intermediate cyclooctene complex appears to be more reactive with respect to CS coordination and more sensitive to oxidation when the arene ring bears electron-withdrawing groups (e.g., C02CH3). Dicarbonyl(methyl rj6-benzoate)-thiocarbonyl)chromium is air stable in the solid state and reasonably stable in solution.9 The infrared spectrum exhibits metal carbonyl absorptions at 1980 and 1935 cm"1 and a metal thiocarbonyl stretch at 1215 cm"1 (Nujol) (these occur at 1978, 1932, and 1912 cm"1 in CH2C12 solution).10 Irradiation of the compound in the presence of phosphite or phosphine leads to slow substitution of CO by these ligands, whereas the CS ligand remains inert to substitution. The crystal structure has been published."... 

Phosphine prepared by this method exhibits a vapor pressure of 170 1 mm. at —111.6°C. (CS2 slush). The literature value is 171 mm.8 Infrared9 and mass spectral10 data have been reported. The infrared spectrum shows t pH at 2327 cm.-1 and also peaks at 1121 and 900 cm.-1. In the gas phase, all these bands show complex fine structure. 

Hydridonitrosyltris(triphenylphosphine)ruthenium(I) is stable in air in the solid state, but slowly oxidizes in solution. The infrared spectrum of the complex shows absorptions at 1965 cm-1 [v(Ru—H)] and 1640 cm-1 [v(N—O)]. The H nmr spectrum (which is temperature-independent) shows a high-field quartet at t16.6 (2Jph = 30 Hz), consistent with a trigonal bipyramidal structure with axial hydride and equatorial phosphines.1 This structure has been confirmed in the solid state by x-ray crystallography,3 which reveals a slightly distorted trigonal bipyramid. The axial nitrosyl is coordinated in a linear fashion (Ru—N—O angle = 176°). 

The infrared spectrum (C6H6 solution) shows inr H at 2070 cm.-1 and vco at 1930 cm.-1. The H n.m.r. spectrum in CDCls shows the aromatic protons at 3.0r and the CH3 protons at 7. 66t in the ratio of 50 3 as calculated for 1 mole of toluene in the complex the Ir—H resonance is observed at 20.7r as a quartet, Jp h = 22 Hz. The unsolvated complex has been shown to be isomorphous with the rhodium analog which has a trigonal bipyramidal structure with the phosphine ligands at equatorial positions.8... 

The bulky ligand tri (cyclohexyl )phosphine reduced copper(II) chloride or bromide in ethanolic solution to CuX P(CeHii)3 2 (X = Cl, Br) complexes. The far-infrared spectrum of the chloro complex indicated that it contained terminal chloride, and the molecular weights of these complexes in solution are consistent with a monomeric formulation (248). Similarly, the molecular weight of CuCl(SbPh3)2—obtained by fusion of the ligand with CuCl— in benzene shows it to be monomeric (329). 

The complex is a yellow, crystalline solid soluble in organic solvents, including hexane. The solid is unstable and decomposes slowly at room temperature and rapidly in solution. It can be stored indefinitely at - 20° under nitrogen. Melting point 36°. TTie infrared spectrum shows v(CO) at 2125(s), 2060(vs), and 2040(vs) (hexane). The complex serves as a useful reagent for the preparation of carbonyl phosphine cobalt(I) complexes, as one or two CO groups can be readily displaced at room temperature by different ligands. 

Similar reactions can also be carried out with triethylphosphine and tributyl-phosphine, and their complexes are much more soluble in hexane. It is important to use pure Co(C6F5)(CO)4 and to monitor the progress of the reaction by the infrared spectrum of samples of the resulting solution (taken by syringe). The hexane solutions obtained after filtration are crystallized by evaporating and cooling to - 78°. 

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