Manifestation of Intermolecular Interactions in the IR Spectra of 8-Azasteroids

We have investigated the intermolecular interactions of 8-aza-D-homogona-1,3,5(10),13-tetrane-12,17a-dione and 2,3-dimethoxy-8-azagone-1,3,5(10),13-tetran-12,17-dione with CHCl3, binary solvents CHCl3–CH3OH, CCl4–CHCl3, and CCl4–CH3OH and also in the solid phase, which manifest themselves in the IR spectra. When the C=O groups of the studied 8-azasteroids form hydrogen bonding with the OH groups of alcohol, the frequencies ν(C=O) change insignificantly. We have found that they are higher than the corresponding frequencies in the IR absorption spectra of solid-phase samples, which is attributable not only to the effect of the medium but also to the possible shortened contacts of the C=O groups with the CH3 and CH2 groups of the molecules under study.