Hydrogen-bonded glycine–HCN complexes in gas phase: structure, energetics, electric properties and cooperativity

摘要: Twelve hydrogen-bonded complexes of glycine and hydrogen cyanide have been studied using high-level quantum-chemical calculations in gas phase. In particular, six 1:1 glycine–HCN dimers 1:2 trimers considered. Besides the characteristics bonds their effect on molecular structure energetics, several electric properties calculated utilising two different models: MP2/6-31++G(d,p) DFT-B3LYP/6-31++G(d,p). Although structural parameters by models are similar, equilibrium electronic energies clusters show model dependence. The lowest energy dimer is same both which ca. 3.0 kcal/mol more stable than highest dimer. However, trimer methods. energetic difference stability between 4.2 (4.4 kcal/mol) at an MP2 (B3LYP) level calculation. bond angles glycine, quite sensiti...