A hydrated 1:1 complex between niflumic acid and ethanolamine, C₁₃H₈F₃N₂O₂⁻. C₂H₈NO⁺.H₂O

Abstract

M_r = 361.3, triclinic, P1̅, a = 6.239 (2), b = 11.280 (2), c = 12.451 (2) Å α = 101.2(1), β = 92.3(1), and γ = 99.9(1)°, V = 844.123 ų, Z = 2, D_x = 1.42, D_m = 1.42 (1) Mg m^-3, λ(CuKα) = 1.5418 Å, μ = 1.102 mm^-1, F(000) = 376, T = 293 K. Final R = 0.064 for 2150 observed reflections. The niflumic acid anions consist essentially of three planar groupings, namely, two six-membered rings and a carboxylate group attached to one of them. The invariant common structural features observed in the crystal structures of fenamates, namely, the coplanarity of the carboxyl group and the six-membered ring bearing it, and the internal hydrogen bond between the carboxyl group and the imino N atom that bridges the two six-membered rings, are retained in the complex. The amino N atom is gauche with respect to the terminal hydroxyl group in the ethanolamine cation. The complexation between the two molecules is achieved through ionic and hydrogen-bonded interactions involving the carboxylate group in niflumic acid.