Optical and electronic properties of a novel zinc complex bis[bis(N-octylsalicylideneamineto) zinc(II)] (1) encapsulated in the nanocavities of Mobile Catalytic Material 41 (MCM-41) have been investigated by both experimental measurement and theoretical analysis. Ultraviolet-visible absorption and emission spectra and excited-state lifetimes of 1 in ethanol solution and nanoporous MCM-41 have been recorded. The bathochromic shift of the 0-0 transitions and the shortening of the excited-state lifetimes have been correlated with the reduction of the band gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital accompanying by the increased energies of the frontier molecular orbitals. The variations of the electronic states and band gaps are correlated with the increase of Coulomb integral a and the resonance integral beta, which has been confirmed by the theoretical calculations. (C) 2003 American Institute of Physics.