Crystal structure of ammonium succinate peroxosolvate

Abstract

The crystal structure of previously unknown ammonium succinate peroxosolvate is studied. It is shown that it represents a rare example of the structure where H 2 O 2 molecule forms two donor hydrogen bonds and does participate in any acceptor hydrogen bonds, despite the presence of substantial quantity of nonperoxide active hydrogen atoms.Peroxosolvates are molecular adducts of hydrogen peroxide with various inorganic and organic compounds. Several of them are widely used in industry, household chemistry and medicine as solid and stable enough sources of hydrogen peroxide in bleaching and disinfection processes. Annual world production of Na 2 CO 3 ·1.5H 2 O 2 and urea peroxosolvates CH 4 N 2 O · H 2 O 2 has risen to hundreds of thousands tons [1].For the first time peroxosolvates of organic compounds were obtained by S. Tanatar in 1908 [2]. He synthesized and established the composition of urea peroxosolvate. That compound immediately attracted great attention both from theoretical and practical points of view. Its crystal structure was completely determined by X-ray diffraction as early as in 1941 [3]. Until quite recently, urea peroxosolvate remains the target of intensive research [4][5][6]. In [2], another peroxosolvate of a simple organic compound was obtained, namely peroxosolvate of succinimide. It was crystallized by slow evaporation of the solution of succinimide in 30% Н 2 О 2 at 50°С. The composition (C 4 H 5 NO 2 ·H 2 O 2 ) was established by permanganatometric titration of the included peroxide [2]. Surprisingly, we did not find any mentions about this compound in the later literature. We made systematic attempts to crystallize this compound from saturated (at r.t.) solutions of succinimide in hydrogen peroxide of various concentrations (30%, 50%, 70% and 96%) by cooling down to +5 °C, -12 °C and -18 °С. However, in all trials the resulting crystals were nothing else but the starting succinimide, as it was shown by X-ray diffraction.It is known that cyclic imides undergo hydrolytic degradation in acidic media resulting in a range of products [7]: Scheme 1.

A new polymorph of ammonium succinate – serendipity in action

“…In the literature, related ammonium salt structures having no functional groups other than carboxylates, show the R 2 4 (8) motif [CSD refcodes AHGLUT (Macdonald & Speakman, 1971), BAMXAR (Churakov et al, 2014), CARVIA (Taka & Kashino, 1999), VOHMOU (Teslya et al, 1990) (Smith, 2014)]. For molecular salts having a long alkyl chain, ammonium palmitate (GUKZOB; Yu et al, 1999) and ammonium myristate (GUKZUH; Yu et al, 1999) show larger hydrogen-bonded ring motifs where the entire carboxylate group is included, giving an R 3 4 (11) motif.…”