Theoretical studies on the hydrogen bonding assemblies based on bispyrimidine and bisbarbituric acid

AM1 method was used to optimize the molecular structure of bispyrimidine, b isbarbituric acid and the entity formed from bispyrimidine and bisbarbituri c acid in a 1:1 molecular ratio through multiple Inter molecular hydrogen b onds. Hydrogen bonding energy was obtained. On the basis of above geometry, the INDO - CI method was used to calculate and discuss the UV - vis spectr a of the three molecules, The results are in good agreement with experiment al ones. It is concluded that multiple hydrogen bonds lead to the formation of new supramolecular aggregates. The interaction principles of hydrogen b onds in the format procession of supramolecular aggregates are also discuss ed.