Molecular Structure and Infrared Spectrum of Solid Amino Formate (HCO 2 NH 2 ): Relevance to Interstellar Ices

Abstract

We report the infrared spectrum of the reaction product of isocyanic acid (HNCO) and water (H2O) at 20 K. The reaction is catalyzed by hydrochloric acid (HCl) even at low temperatures. The resulting product is identified to be amino formate (HCO2NH2). This identification has been achieved by comparison of the IR spectrum of the product with the corresponding spectra of formic acid (HCO2H), methyl formate (HCO2CH3), and formamide (HCONH 2), all of which have the H-C=O group. The results of ab initio quantum mechanical calculations of the harmonic frequencies and the infrared intensities of the most stable structure containing NH2OCHO groups also agree with the laboratory data. Such complex organics may be produced on the cold interstellar grains and on planetary objects by radiation and/or catalytically induced reactions involving simple C-, H-, N-, and O-containing species.