Infrared Spectra of Substituted Chalcones and Some of Their Ferrocene Analogues

The infrared spectra of substituted chalcones and some of their ferrocene analogues were measured in the region of fundamental and first overtone C = 0 stretching bands. The formation of hydrogen bonds between the substituted chalcones and phenol was examined in the O—H stretching region. The frequencies of fundamental and first overtone C = 0 stretching bands for s-cis and s-trans conformers and also Av(OH) values were found to be linear dependent upon сг-constants of substituents in a series of 3and 4-substituted and 3'and 4'-substituted chalcones. Linear correlations between the C = 0 stretching frequencies and a-constants were found also in two series of substituted ferrocene analogues of chalcones. Bearing the obtained results in mind a transfer of the substituent effect through the double bond, through the bonding system in s-cis and s-trans conformations and the effect of a ferrocenyl residue on this transfer is discussed.