The Study On The Structural And Thermodynamic Properties Of Solution: Rism Thory And Quantum Computation

Whether biochemical processes of the natural world or various chemical production processes, most of the chemical reactions are carried out in solution. Solvent effect is a widespread phenomenon, which has a major impact on the structural and thermodynamic properties. Studying chemical reaction rate, reaction equilibrium and reaction mechanism has an important economic impact on the efficient production of industrial products. As the most reliable method to study the molecular fluid structure, referenced interaction site model can also calculate the various thermodynamic properties of solvent effect. In addition, the molecular structure and solvation thermodynamic properties are carried out by GAUSSIAN 03 program. The results are compared with those of RISM. The main contents are summarized as follows:1. The structural and thermodynamic properties of aqueous dimethyl sulfoxide at a mole fraction of 0.002 were investigated using Referenced Interaction Site Model theory at 298 K. The results reveal that the water network structure is enhanced by the presence of DMSO. The increased fluctuation in the potential of mean force suggests that the water-induced force is repulsive. In addition, the increased entropy of solvation and free energy of solvation imply that the randomness of the solution increases with an increase in temperature. The increased interaction energy and excess chemical potential reveal that the solution deviates from an ideal solution. Furthermore, the increased cavity reorganization energy shows that the system structure reorganizes easily at high temperature.2. The structural and thermodynamic properties of aqueous TMAO at a mole fraction of 0.002 were investigated using Referenced Interaction Site Model theory at 298 K. We analyse the radial distribution functions of the TMAO molecules and water molecules pairs in solution and the solvent effect on the thermodynamic properties. The results reveal that the molecular structure in solution becomes more stable and orderly. The solvation process is radiative and entropy consumption.3. The solvent effect of aqueous TMAO is studied by GAUSSIAN03 program. We carry out the optimized structure by the all atoms model and list the bond length and bond angel. In addition, we compute the thermodynamic properties by the program, which are consistent with those of RISM.