MOLECULAR-STRUCTURES OF BENZOYLBENZO-12-CROWN-4 AND DIPHENYLACETYLBENZO-12-CROWN-4 AND POSSIBLE REASONS FOR DIFFERENT CONFORMATIONAL STATESOF THEIR MACROCYCLES

The molecular structures of (benzoyl)benzo-12-crown-4 (a = 22.387, b = 4.503, c = 16.167 angstrom, d(calc) = 1.34 g cm-3, Z = 4, space group P2(1)nc, DAR-UM, Cu-Kalpha, R = 0.056) and (diphenylacetyl)benzo-12-c rown-4 (a = 8.866, b = 23.337, c = 10.737 angstrom, d(calc) = 1.25 g c m-3, Z = 4, space group P2(1)2(1)2(1), DAR-UM, Cu-Kalpha, R = 0.056) h ave been investigated. The differences in the conformations of the mac rocycles and the degree of conjugation between the benzene ring pi orb itals and the lone pairs on the adjacent oxygen atoms in the macrocyle are discussed.