Theoretical studies of spin arrangement of adsorbed organic radicals in metal-organic nanoporous cavity

The adsorption properties in nanoporous crystals of a metal-organic framework were studied theoretically. The Zn-3(BDC)(3). 6CH(3)OH (BDC = 1,4-benzenedicarboxylate) crystal was mainly treated as a stable metal-organic assembled species, which was reported by O.M. Yaghi and co-workers. Its crystalline structure very much resembles several crystals that have been reported by W. Mori et al. For adsorbed molecules, N-2, CO2, Ar and H-2 for nonmagnetic species and O-2 for magnetic radical species were treated. The following systematic procedures were carried out: (1) decision of parameters for MC simulations; (2) execute MC simulation; (3) search of configuration of O-2 molecules by MM method; and (4) study of magnetic interactions by means of ab initio HF, post-HF and DFT methods. Finally, magnetic interactions between O-2 pairs exist and this cooperation might run in the nanoporous cavity. (C) 2001 Elsevier Science Ltd. All rights reserved.