FTIR Spectroscopy of Intermolecular Interactions of Ethers with Methanol: Cooperativity Effect

FTIR spectral analysis of solvation effects on the frequencies of O–H stretching vibrations of methanol complexes with linear (diethyl ether, di-n-butyl ether, and diglyme) and cyclic ethers (1,4-dioxane, 12-crown-4, 15-crown-5, and 18-crown-6) was carried out. The comparative analysis of the influence of solvation effects on the frequencies of O–H groups of methanol in aprotic solvents for both free and bound molecules with ethers (B) had been performed. Complexes in proton-donor solvents as well as in chloroform were investigated to quantify the change in the strength of X–H···B (where X = O) hydrogen bonds due to cooperative interactions. The influences of structure and size of the ether cycle on the contribution of the cooperativity effect of methanol with ethers are discussed.