[Investigation of the Interaction between 1,3-Dimethylurea and Solvent by Raman Methods].

Urea family plays significant role in the bio-science area. Because of the unique frame, they can form Hydrogen bond with water as well as other substance. Hydrogen bonds are normal weak interactions in the system of bio-molecules. A Raman spectrum is the most powerful method to obscure the Hydrogen bond interaction between molecules. Initially, we measure the Raman spectra of DMU crystal, and then use density function theory with a B3LYP/6-311G* * basis set to optimize the geometry structure and calculate the vibrational frequency of gas phase DMU, which assigns the Raman pecks. Then, measure the solvent. When dissolving DMU in water, the interaction between DMU-DMU will replaced by the interaction between water-DMU. The orbital hybridization of nitrogen atoms changes from the solid-state the sp' orbital hybridization to sp3. So, the frame of this molecule goes from in-planet to out of plant during this process.