Structure and Conformation of Pyridino- and Diesterpyridino-18-crown-6 Complexeswith Primary Ammonium Salts in Solution and Crystalline States. (Reannouncement with New Availability Information)

摘要

2Structures in CD3OD-CDC13 mixtures of pyridino-18-crown-6 and diesterpyridino-18-crown-6 complexes with primary ammonium cations containing an alpah-phenyl group were found to be significantly different. The pi-pi overlap between the alpha-phenyl group of the ammonium cation and the pyridine ring of the ligand occurs in the pyridino-18-crown-6 complexes but not in the diesterpyridino-18-crown-6 complexes. The solution structure of a diesterpyridino-18-crown-6 complex with an alpha-phenyl-containing primary ammonium cation was also found to differ markedly from the corresponding crystal structure in that pi-pi overlap occurs in the crystal structure, but not in the solution structure.