Crystal and molecular sturcture of pyrylium salts: Part II. Crystal and molecular structure of 2,6-diphenyl-4-(4-nitrophenyl) pyrylium perchlorate nitromethane solvate, electronegativity effect on geometry of the action

Abstract

The crystal and molecular structure of 2,6-diphenyl-4-(4-nitrophenyl)pyrylium perchlorate nitromethane solvate was solved with R=0.067 for 2827 reflections and mean esd for bond lengths 0.005Å and bond angles 0.4°. Phenyl rings attached to positions 2,4 and 6 of the pyrylium ring exhibit a strong deformation of angular geometry indicating enhanced electronegativity of carbon atoms 2,4 and 6 due to the positive charge on them. Exocyclic valence angles at carbon atoms 2 and 6 of the pyrylium ring are strongly deformed from 120° due to the strongly electronegative oxygen atom with partial positive charge, STO-3G, 3-21G and 6-31G * ab initio calculations support this interpretation.