Chirality Properties of Modeling Water in Different Aqueous Systems

Abstract

The research addresses the problem of chirality existence in modeling water with various impurity molecules using new numerical algorithm of chirality deter-mination. It is based on asymmetry analysis of molecular system composed of water molecules. The following molecular systems are investigated: (1) small water clusters such as (H 2 O) n , K + (H 2 O) m , and Na + (H 2 O) m (n = 4÷8, m = 5÷10) at temperature 1 K; (2) (H 2 O) n , K + (H 2 O) p , and Na + (H 2 O) p (n = 4÷9, p = 5÷8) at temperature 300 K; and (3) chiral biological molecules of L-valine, D-valine, L-glycerose, and D-glycerose and left or right water clusters (H 2 O) 4 with water molecule ’ s shell with thickness varied from 4 to 14 Å with a step of 2 Å. The systems (1), (2) are investigated by Monte Carlo method and the interaction is simulated with Poltev-Malenkov potentials. Systems (3) are initiated using Solvate software, and then aqueous systems are optimized by the conjugate gradient algorithm using the MMFF94 potential. It is revealed that there is no predominance of right-handed or lefthanded substructures in all studied configurations of water molecules. But in small aqueous systems (2), (3), the number of types of water structures, taking into account chirality, depends on the presence of impurity ion and its type.