Analysis of the vibrational spectra of trans-N,N′-bis-R-salicylidene-1′,2′-cyclohexanediamine

Vibrational spectra of trans-N,N′-bis-(R-salicylidene)-cyclohexanediamine (R = H, 5-NO2, 4,6-OCH3, 3,5-Cl) and its analogues deuterated in OH and imine CH groups were calculated using DFT method at 6-31G** level. The presence of strong coupling in the molecules was evidenced.