Computational Study on the Interaction of C4H4Y (Y=O, S, Se) with BX3 (X=H, F, Cl)

The geometries and binding energies of the complexes between C4H4Y (Y=O, S, Se) and BX3 (X= H, F, Cl) have been calculated at the density function theory B3LYP and the second-order Moller-Plesset theory MP2(full) levels. The vibration and natural bond orbital analyses were carried out, which indicate that the 18 conformers obtained include π-p interaction (the BX3 locating exactly above the C=C double bond) and n-p interaction (the boron atom directly combining to O, S or Se). The stabilities of C4H4Y-BH3 complexes are in the order of n-p>π-p. The stabilities of C4H4Y-BF3 and C4H4Y-BCl3 com- plexes with n-p interaction are relative to the π-p type complexes. The calculated results show that charge transfers, frequency shifts and change of geometries are relative to the stabilities of the complexes in the forming process. Keywords density function theory; C4H4Y-BX3 system; π-p interaction; n-p interaction