Small-molecule Research, And Theory Of Hydrogen Bonding Between Water Molecules

Hydrogen bonding plays a critical role in a wide range of chemical and biological phenomena. Therefore hydrogen-bonded complexes have received more and more extensive theoretical study. Water exists all over the world, and a large number of chemical reactions occur in aqueous solution. Moreover, water is one of the molecules that are the easiest to form hydrogen bonding. Therefore, there must be hydrogen bonding largely both in nature and in organisms. And it will be very interesting and of guiding meanings to make a study on the interactions of water with other molecules. However, accurate experimental study of the hydrogen-bonded complexes has still been a more elusive goal due to experimental difficulties. And it is expected to make some theoretical studies.In this paper we studied the interactions of small molecular and water using the B3LYP, MP2 and HF methods at different basis sets levels. The optimized geometric parameters, interaction energies and the infrared spectrum frequencies, IR intensities are investigated. The solvent effects were investigated using SCRF calculations, too. The results indicate that the polarity of the solvent has played an important role on the structures and relative stabilities of different isomers.Charity is a universal phenomenon and plays a critical role in biological science. A lot of important biological activities are realized by rigid charity matching. Thus we studied the charity taking the hydrogen-bonded complexes formed between two charily molecules (the lactic acid and H2O2) for example. We hope that it will be helpful to the studies in future.In this paper, a lot of theoretical information is afforded on the system of hydrogen bonding complexes between small molecules and water. These will not only assist people to know these new complexes but also guide the experimentations and further theoretical study in the future.