The ground- and excited-state intramolecular proton transfer processes of 2-（2-R （R=OH, NH2, SH） phenyl （or pyridyl）） benzoxazoles （or benzothiazoles） are investigated by the DFT methods. The calculated results indicate that in the ground state there is a high correlation （R=0.9950） between the proton transfer barrier and the intramolecular hydrogen bonds （IMHB） strength. The increase of the strength of IMHB in the proton transfer processes leads to a larger barrier contributions. Intramolecular proton transfer process pathway is along with the minimal difference of change value in the IMHB angle. In the excited-state, there is a similar relationship between the IMHB and the bartier.
Density functional calculations have been carried out on a series of fluorinated empty cages XnFn （n=2-20） with X=Si, Ge, and Sn. It indicates that the fullerene-like cage structure with pentagons turns out to be the most stable with n increasing, and the stability of the XnFn isomers increases with the number of five-membered rings. The HOMO-LUMO gap for Ge （n=6, 10） cages is found to be even larger than the values for Si cages, though in bulk Ge has a smaller band gap than Si. Moreover, calculation of the Gibbs free energy of oligomerization reaction of SiF→1/n （SiF）n showed that this reaction is exothermic even at 900 K, indicating the favorability of their formation from the SiF monomer.
