Catalytic effect of water, ammonia, formic acid, or sulfuric acid on the HCN + H 2 O reaction in the aqueous solution
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ORIGINAL RESEARCH
Catalytic effect of water, ammonia, formic acid, or sulfuric acid on the HCN + H2O reaction in the aqueous solution Benni Du 1 & Weichao Zhang 1
&
Yingqiu Gu 1
Received: 27 May 2020 / Accepted: 12 August 2020 # Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract The effect of water (W), ammonia (AM), formic acid (FA), or sulfuric acid (SA) on the HCN + H2O reaction in the aqueous solution has been investigated at the CCSD(T)/6-311++G(2df,2pd), PCM (water)//M06-2X/6-311++G(d,p) + 0.967 × ZPE levels of theory. In addition, transition state theory (TST) has been used to calculate the bimolecular rate constants for the HCN + H2O reaction catalyzed by W, AM, FA, or SA. Our calculations reveal that SA is a significantly more effective catalyst for the hydrolysis of HCN to form formamide (NH2CHO) compared with W, AM, and FA. Keywords HCN . Solution-phase hydrolysis . Reaction mechanism . Catalytic effect
Introduction Due to containing the peptide linkage [−(O)C−N(H)−], formamide (NH2CHO) is considered as the simplest and one of the important components of life. Furthermore, formamide has also been found to be widely distributed in the universe. It has been detected not only in the interstellar medium [1] but also in comets, stellars, galactic center, etc. [2–4]. Accordingly, formamide is considered as an important prototype molecule from which prebiotic molecules can be synthesized [5, 6]. Formamide is one of the interstellar complex organic molecules (iCOMs) and it can be generated from the mixtures of simpler molecules, for example, from the ice mixtures of H2O + CH4 + N2 [7], HCN + H2O [8, 9], and HCN + H2O + NH3 [9]; from frozen mixtures of CO + NH3 [10]; and from the mixtures of CO + NH3 + H2O by impact plasma or electric discharge [11]. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11224-020-01618-5) contains supplementary material, which is available to authorized users. * Weichao Zhang [email protected] * Yingqiu Gu [email protected] 1
School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou 221116, Jiangsu, People’s Republic of China
Hydrogen cyanide (HCN) has been identified in the gas phase of the interstellar medium and some comets and is one of the most studied precursors of prebiotic chemistry [12–14]. For the reaction of HCN with H2O, several experimental investigations have been carried out to examine the possible biological significance for it. In 1933, Krieble and Peiker [15] investigated the hydrolysis of HCN at 65 °C with sulfuric acid as catalyst. The velocity constants calculated by the usual monomolecular formula were given. Moreover, Krieble et al. [16] also studied the velocity constants for the hydrolysis of HCN catalyzed by sulfuric acid in acetic acid solutions at 45 °C based on a first-order reaction. In 2004, Gerakines et al. [9] studied the energetic processing by ultraviolet photolysis and proton irradiation on the ice mixtures of H2O + HCN at low temperature (18 K) and g
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