STOICHIOMETRY OF THE SHORT-RANGE SOLVATION OF DIETHYLAMINE IN PROTON TRANSFER REACTIONS WITH 2,4-DINITROPHENOL AND SOLVATION BY ETHERS

Article abstract of DOI:10.1016/0022-2860(90)80146-B

Equilibrium constants were determined at 25 deg C for the formation of the proton transfer complex between 2,4-dinitrophenol and diethylamine in mixed solvents of benzene and small amounts of the following electron-donating solvents: nitrobenzene, n-propyl ether, 1,2-dimethoxyethane, tetrahydropyran, and 1,3-dioxalane.These solvents form hydrogen bonds with the amine proton of diethylamine, resulting in an increased effective basicity for the amine.In every case the stoichiometry of the interaction is found to be diethylamine:solvent = 1:2, inferring the existence ofa bifurcated hydrogen bond in solution.Dioxane had previously been shown to be a dramatically effective short-range solvent.Of the several ethers that were studied to determine what structural aspect of dioxane is responsible for its solvation powers, only 1,3-dioxalane, another cyclic diether, shows similar properties.