STRUCTURE OF SODIUM HYDROGEN GLUTARATE DIHYDRATE

C5H7O4-.Na+.2H2O, M(r) = 190.1, monoclinic, P2(1)/c, a = 5.371 (1), b = 13.367 (1), c = 11.587 (1) angstrom, beta = 93.72 (1)-degrees, V = 830.0 angstrom3, Z = 4, D(m) = 1.52 (by flotation in heptane/iodobutane), D(x) = 1.527 g cm-3, lambda(Cu K-alpha) = 1.5418 angstrom, mu = 16.1 cm-1, F(000) = 400, T = 293 K, R = 0.034 for 1602 unique observed reflections. The structure contains very short formally asymmetric hydrogen bonds [O...O 2.410 (2), O--H 1.07 (4), H...O 1.35 (4) angstrom] which link glutaric acid residues into infinite chains. Six-coordinate Na+ ions linked by water molecules are arranged in columns parallel to a. An unusual feature of the structure is that neither of the O atoms involved in the short hydrogen bond is coordinated to the Na+ ion.