MO analysis of regiochemistry of C60[Pt(PH3)2]2

We have modified the ASED-MO parameters for C atom so as to yield the energy level correlation, optical transition gap, and proper structure for the previous results of C60. In order to study eight regioisomeric bisadducts of C60[Pt(PH3)2]2, we calculate the structure and electronic properties for monoadduct and each regioisomer of bisadducts and compare the relative stability with the ASED-MO method. Here equatorial and trans-3 regioisomers are more stable than the others. Our calculated results and point group suggest that the observation of only three isomers of [(Et3P)2Pt]2C60 by the 31P NMR would be explained by the three kinds of group isomers (e, trans-3; Cs), (trans-4, D2h), and (trans-2, trans-1; C2).