Structures of ethylammonium hydrogen succinate and diethylammonium hydrogen succinate at 110 K

Structure of sodium hydrogen succinate at 123 K

“…This anion has 1 symmetry and the sodium cation occupies a site of symmetry 2, as in many other acid salts where the moleculax symmetry is dictated by crystallographic symmetry. The bond lengths and angles of the hydrogen succinate residue are in very good agreement with those recently reported for the alkylammonium salts (Kalsbeek & Larson, 1991;Kalsbeek, 1991), and also for the lithium, potassium and caesium salts (Kiippers, 1982;McAdam, Currie & Speakman, 1971;) with which the sodium salt is not isomorphous. Unlike the majority of the succinate salts, the anion deviates markedly from planarity (see Table 2) with C(2 i) displaced 1.28 A from the mean plane defined by O(1), O(2), C(1) and C(2).…”

“…A recent structural study of some alkylammonium salts of the hydrogen succinate anion has suggested that the H atom in the short hydrogen bond is best described by two equally populated sites on either side of the centre of the bond, i.e. a double-minimum potential function rather than a single-minimum_potential function with the H atom located on the site of 1 symmetry (Kalsbeek & Larson, 1991;Kalsbeek, 1991). This conclusion was reached following consideration of the more reasonable H-atom thermal parameters given by the double-potential-minimum model.…”

Structure of ammonium hydrogen succinate above and below the phase transition around 170K

“…Although a librational motion around a long molecular axis P1 is remarkably larger than those around P2 and P3, the temperature dependency is almost equal. The conformation of the C4H504-ion is gauche; C(1)----C(2)--C(3)--C(4) = -70.4 (2) ° at 297 K, -70.6(2) ° at 190K and -70.2(1) ° at 150 K, while the conformation is trans in many other acidic salts of alkaline metals (McAdam, Currie & Speakman, 1971;Ktippers, 1982, Kalsbeek, 1991, 1992Kalsbeek & Larsen, 1991;Hauss0hl & Schreuer, 1993). The torsion angle and r.m.s, radius of gyration around each principal axis show no remarkable difference in molecular conformations for all temperatures.…”

“…The acidic salts of succinic acid (MHC4H404; M = Li ÷, Na +, K +, Rb +, Cs +, NH4 ÷, CH3NH3 ÷ and C2HsNH3 ÷) are of much interest, because they have very short hydrogen bonds with O..-O 2.41-2.50/~, (McAdam, Currie & Speakman, 1971;Ktippers, 1982, Kalsbeek, 1991, 1992Kalsbeek & Larsen, 1991;Haussiihl & Schreuer, 1993). The hydrogen succinate ion (C4H504-) has no symmetry in the crystals of NH4+.C4HsO4 - (Haussiihl & Schreuer, 1993) and C2HsNH3+.CaHsO4 - (Kalsbeek, 1991), but symmetry i, 2 or 2/m in the other acidic salts (McAdam, Currie & Speakman, 1971;Kiippers, 1982, Kalsbeek & Larsen, 1991Kalsbeek, 1992).…”

Structures of a partially deuterated sodium trihydrogen dimalonate and sodium hydrogen malonate (a reinvestigation) at 120 K

“…Introduction. The crystal structure determinations of partially deuterated sodium trihydrogen dimalonate (1) and sodium hydrogen malonate (2) have been performed as a continuation of earlier studies of acid salts of malonic acid and succinic acid with special interest in the hydrogen bonding (Kalsbeek & Larsen, 1991;Kalsbeek, 1991). Acid salts of carboxylic acids and dicarboxylic acids have been extensively investigated structurally (Speakman, 1972) and spectroscopically (Had~i, 1965).…”