VARIATION OF MOLECULAR-GEOMETRY AND AROMATIC CHARACTER OF CHRYSENE AND PERYLENE IN THEIR EDA COMPLEXES - REFINEMENT OF X-RAY CRYSTAL AND MOLECULAR-STRUCTURE OF CHRYSENE AND PERYLENE

Precise geometries (esd for CC-bond lengths less-than-or-equal-to 0.00 2A) of chrysene and perylene obtained from new X-ray diffraction measu rements are reported. Comparison with geometries of chrysene and peryl ene involved in EDA complexes and application of aromaticity indices ( HOMA, I6) for these systems have shown that considerable changes in ge ometry and local aromatic character are observed mostly for the rings of lower aromaticity, i.e. in central rings of chrysene and perylene.