Infrared spectra carbonyl hydrides

The redox condensation shown in Eq. (9) gives rise to the dianion [Fe3Ni(CO)12]2 and it has also been possible to isolate salts of the corresponding hydride, [Fe3Ni(CO)12H]- (30.5 r). The presence of infrared absorptions due to bridging carbonyls and the complexity of the infrared spectrum indicate a structure similar to Co4(CO)i2 with the nickel in the basal plane171). 

The trans-fused octahydrobenzo[g]quinoline (60) is formed when the related 2-benzylpiperidine-3-carboxylic acid is heated in polyphosphoric acid. The 5-carbonyl group in the product is reduced to a metl lene group by lithium aluminium hydride-aluminium chloride (J.G. Cannon et dl. J. med. Chem., 1984, 190). The stereochanical assignment is based on the strong absorption at 2780 cm in the infrared spectrum of (60) and the large (65 Hz) chemical shift difference exhibited by the benzyl... 

Under syn gas pressure the rhodium acac precursors were converted to the catalytically active hydride complexes HRh(CO)2(L-L). The complexes are generally assmned to have a trigonal bipyramidal structure and two isomeric structures of these complexes are possible, containing the diphosphite coordinated in a bisequatorial (ee) or an equatorial-apical (ea) fashion. The structure of the complexes can be elucidated by (high pressure) IR and NMR data (Table 3). In the carbonyl region of the infrared spectrum the vibrations of the ee and ea complex can be easily distinguished. The ee complexes typically show absorptions around 20 15 and 2075 cm [24, 26,... 

Three major infrared absorptions occur in the carbonyl stretching region near 2014, 2005, and 1982 cm (cyclohexane) and the molar absorptivi-ties at these positions are 86, 22, and 2.7 L g cm S respectively. The metal-hydrogen stretching absorptions are at 1882 cm" for the hydride and 1313 cm for the deuteride (cyclohexane). A singlet is observed in the HNMR spectrum at d —5.88 (hexane). The gas-phase IR and Raman spectra as well as the UV-Vis spectrum have also been reported. 

Infrared spectroscopy has assisted in the determination of the structure of certain complex inorganic molecules, uch as the metal carbonyls, inter-halogen compounds, boron hydrides, and nitrogen oxides. The practice used has been to compare the observed spectrum with the spectrum expected for an assumed model on the basis... 

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