Morpholinium 2,4-dinitrophenolate Aqua Salt and Ethylenediammonium 2,4-dinitrophenolate Aqua Salt

Abstract

The structures of the aqua salts of 2,4-dinitrophenolate (2,4-DNP⁻) with ethylenediammonium (EDA²⁺) and morpholinium (MP⁺) have been determined by X-ray diffraction, the first with 2:1 stoichiometry. The EDA²⁺ salt crystallizes in P_21/c space group, with a = 5.887; b = 23.441; c = 7.075, β = 96.61, R1 = 0.0365 for reflections with Fo > 4sig(Fo). MP⁺ salt crystallizes as P_–1 space group; a = 6.655; b = 9.388 c = 11.452; α = 104.82 β = 102.31 γ = 105.24, with R₁ = 0.0334. Phenolates and ammonium groups interact through hydrogen bonds and the N+···O distances for MP⁺ and EDA²⁺ salts are 2.783 Å and 2.812 Å, respectively. There is one water molecule by asymmetric unit, interacting with phenolate and ammonium ions. The arrays of hydrogen bonds are cyclic, with six and four members alternated and the position of the units is dependent on the ability to form hydrogen bonds. The Job’s plot for ethylenediamine and 2,4 dinitrophenol shows the same 2:1 stoichiometry in ethanol for EDA²⁺-2,4-DNP⁻ salt.

Graphical abstract

Structures of the dinitrophenolate aqua salts of morpholinium and ethylenediammonium are described with cyclic networks of hydrogen bonds between the species.