Polysulfonylamine, CXVIII Wasserstoffbrücken in kristallinen Onium-dimesylamiden: Drei prim. -Ammonium-dimesylamide mit zwei- oder dreidimensionalen Wasserstoffbrückenmustern/Polysulfonylamines, CXVIII Hydrogen Bonding in Crystalline Onium Dimesylamides: Three prim. -Ammonium Dimesylamides Exhibiting Two- or Three-Dimensional Hydrogen Bond Patterns

Abstract

In order to study hydrogen bonding patterns in primary ammonium salts and the hydrogen bond acceptor potential of the dimesylamide anion, low-temperature X-ray structures have been determined for the 1:1 salts RNH3 +(MeSO2)2N- , where R = Et (1, monoclinic, space group P21/n, two independent formula units A and B) or 1-adamantyl (2, monoclinic, P21/C) and for the 1:2 salt [H3NCH2CH2NH3]2+ ·2 (MeSO2)2N- (3, monoclinic, P21/n, cation crystallographically centrosymmetric). The NH3 + donor groups form two-centre or three-centre hydrogen bonds to four (B) or three (A, 2, 3) adjacent anions, giving rise to fundamentally different networks. The crystal packing of 1 displays a three-dimensional system of eight independent H bonds and may be viewed as a commensurate ionic self-clathrate, in which finite (A)2 cyclodimers are inserted as guest entities into parallel tunnels between infinite (B)∞ tapes. In contrast, owing to the steric demands of the 1-adamantyl group, compound 2 merely exhibits a twodimensional pattern constructed from four independent H bonds and leading to cation-anion sheets. In the packing of 3, two crystallographically independent H bonds generate a tape substructure of cations and anions in the ratio 1:2; these tapes are cross-linked into a three-dimensional network via a third independent H bond. In each of the structures, short C -H ··· A contacts (A = N- and/or O) with H ··· A ≤ 260 pm and C - H ··· A ≥ 130° are observed.