Investigation of substituent effects of chalcones by ¹³C n.m.r. spectroscopy

Abstract 13 C chemical shifts for 23 para ‐ and meta ‐substituted chalcones of the types 1 and 2 have been determined. The aromatic shieldings are compared with previous results for other aromatic derivatives. Correlations of the 13 C chemical shifts of vinyl carbons and carbonyl carbons as well as ring carbons with Hammett σ parameters, π electron densities and the reactivity parameters of Swain and Lupton provide a consistent picture of electronic effects transmitted through the carbon framework of the compounds studied.