The Shpol'skii system perylene in n-hexane:: A computational study of inclusion sites

We present a combined quantum mechanics/molecular mechanics study of the Shpol'skii system perylene/n-hexane. The system was modeled utilizing a customized pcff-derived force field optimized with a balanced set of optimization criteria based on geometry, vibrational modes, and the energies and forces in an ensemble of molecular geometries. Spectral shifts were calculated perturbatively using the method of Shalev [J. Chem. Phys. 95, 3147 (1991)]. The calculated shifts are within the experimental uncertainty of the observed 0-0 lines and allow an unambiguous assignment of the three most prominent sites. The proposed assignment differs from that of a previous study. (C) 2000 American Institute of Physics. [S0021-9606(00)70204-2].