Methanol (MetOH), an important prebiotic molecule, hydrochloric acid (HCl), and water have already been detected in the molecular cloud Sagittarius B2 (Sgr B2). The substitution reaction 3MetOH+(H3O)+(H2O)3Cl−→(H3O)+ (MetOH)3Cl−+3H2O is studied. The first ion pair can be generated readily from HCl and water. The time to yield an appreciable amount of the ion-pair product can be only a few years.
Organic molecules are a potential source of prebiotic chemistry in the interstellar medium (ISM). Methanol (MetOH) is a very important source of more complex molecules. H3O+(aq) and Cl−(aq) are fundamental to living organisms and can be generated in the ISM from the dissociation of HCl with just four water molecules, yielding the (H3O)+(H2O)3Cl− ion-pair. Here, a detailed mechanism, based on density functional theory (DFT) and ab-initio (2nd order Mϕller-Plesset perturbation theory, MP2) calculations, is suggested for the substitution reactions of these water molecules by MetOH. The time required for formation of an appreciable amount of the product ((H3O)+(MetOH)3Cl−) can be only few years. Such reaction can take place in Sagittarius B2, where HCl, H2O and MetOH have already been identified and it can be an important source for the formation of more complex prebiotic structures.Zum Volltext