3656b.     STERNBERG, H. W., WENDER, I., FRIEDEL, R. A., AND ORCHIN, M.  Chemistry of the Metal Carbonyls.  II.  Preparation and Properties of Cobalt Hydrocarbonyls.  Jour. Am. Chem. Soc., vol. 75, 1953, pp. 2717-2720.

          New method for the preparation of Co hydrocarbonyl is based the reaction between dicobalt octacarbonyl and pyridine whereby a Co salt of Co hydrocarbonyl is obtained readily and quantitatively:

          3[Co(CO)₄]₂+12Pyr→2[Co(Pyr)₆] [Co(CO)₄]₂+8 CO  Addition of salt to excess dilute H₂SO₄ in a stream of inert gas over a period of about 45 min. gave pure Co hydrocarbonyl in a yield of 95%.  Co hydrocarbonyl is stable in aqueous solution and behaves like a strong mineral acid.  The half life in the gas phase and in hexane solution is dependent upon its concentration.  The infrared spectra of Co hydrocarbonyl in the gas phase and in hexane solution were determined in the 2-15μ region.  Neither of these spectra showed the presence of a conventional hydroxyl band.  In addition the deutrocarbonyl was prepared to check for the expected shift of spectral bands, but the spectrum was identical to that of the hydrocarbonyl.  Mass spectrometric analysis of Co hydrocarbonyl gave peaks for Co(CO), Co(CO)₂, Co(CO)₃ and Co(CO)₄ and H₂.  The latter was not found as part of any other fragment.