Structure and Electronic Properties of Hollow-Caged C60 Fullerene-Derived (MN4)nC6(10-n) (M = Zn, Mg, Fe, n=126) Complexes

Unique hollow-caged (MN4)(n)C6(10 - n) (M = Zn, Mg, Fe, n = 1 - 6) complexes designed by introduction of n porphyrinoid fragments in C-60 fullerene structure were proposed and the atomic and electronic structures were calculated using LC-DFT MPWB95 and M06 potentials and 6-311G(d)/6-31G(d) basis sets. The complexes were optimized using various symmetric configurations from the highest O-h to the lowest C-1 point groups in different spin states from S = 0 (singlet) to S = 7 (quindectet) for M = Fe to define energetically preferable atomic and electronic structures. Several metastable complexes were determined and the key role of the metal ions in stabilization of the atomic structure of the complexes was revealed. For Fe6N24C24, the minimum energy was reported for C-2h, D-2h, and D-4h symmetry of pentet state S = 2, so the complex can be regarded as unique molecular magnet. It was found that the metal partial density of states determine the nature of HOMO and LUMO levels making the clusters promising catalysts. (C) 2014 Wiley Periodicals, Inc.