Hydrogen bond interactions in the binary solutions of ethyl acetate with nitrobenzene: Spectroscopic, theoretical and dielectric studies

FTIR spectroscopic studies has been carried out on pure ethyl acetate (EA), nitrobenzene (NBZ) and their equimolar binary solution. Theoretical calculations have been performed to validate the results of the FTIR spectral studies. Through the calculations, it is found that dimers of cyclic geometry with the hydrogen bonds between the methyl/methylene hydrogen and ester linkage oxygen (oxygen that is bonded with carbon through the single bond) can prevail in neat EA. These dimers, being highly unstable, dissociate into monomers in the binary solution and participate in the formation of 1:1 and 1:2 (EA:NBZ) systems. The 1:2 system is found to be more stable than the NBZ and EA dimers and the 1:1 system. The EA-NBZ solutions of entire composition range have been subjected to dielectric relaxation studies at 298 K using Time Domain Reflectometry (TDR) in the frequency range 10 MHz to 30 GHz. The results obtained have been interpreted with the aid of the findings of FTIR studies and DFT calculations.