Density functional studies on the endohedral complex of fullerene C70 with tetrahedrane (C4H4): C4H4@C70.

B3LYP/6-31G(d) hybrid HF/DFT calculations were carried out to determine the structural and electronic properties of the endohedral complex of a C(70) cage with tetrahedrane (C(4)H(4)). It was demonstrated that the formation of the complex is endothermic, with a destabilization energy of 72.56 kcal mol(-1). C(4)H(4) is seated in the center of the C(70) cage and exists in molecular form inside the fullerene. C(4)H(4) endohedral doping slightly perturbs the molecular orbitals of C(70). The calculated HOMO-LUMO gaps, the electron affinity (EA), and the ionization potential (IP) indicate that C(4)H(4)@C(70) is more chemically reactive than C(70). The IR active modes and harmonic vibrational frequencies of C(4)H(4)@ C(70) are also discussed.