Infrared Spectrum of HCO

Abstract

HCO and DCO have been prepared by the photolysis of HI (DI) and of H₂S (D₂S) in a CO matrix at 14° and at 20°K. The earlier infrared spectroscopic identification of these species has been confirmed. The C=O stretching frequency of DCO has been revised to 1800 cm^—1. Unusually low C–H and C—D stretching frequencies, 2488 and 1937 cm^—1, respectively, are obtained. Observations on H¹³CO and D¹³CO support these assignments. Spectroscopic, kinetic, and electron spin resonance data all suggest that the C–H bond is exceptionally weak. Fermi resonance may occur between the C—D and C=O stretching modes of DCO. Evidence is presented suggesting that considerable activation energy is required for the reaction of H atoms with CO.