Poly[bis(μ-2-amino-4-nitrobenzoato)di-μ-aqua-dirubidium]

Abstract

Key indicators: single-crystal X-ray study; T = 200 K; mean (C-C) = 0.006 Å; R factor = 0.046; wR factor = 0.075; data-to-parameter ratio = 12.3.In the structure of the title salt, [Rb 2 (C 7 H 5 N 2 O 4 ) 2 (H 2 O) 2 ] n , the asymmetric unit comprises two independent and different seven-coordinate Rb + cations, one forming an RbO 7 polyhedron, the other a RbO 6 N polyhedron, each of which is considerably distorted. The RbO 7 polyhedron comprises bridging O-atom donors from two water molecules, three carboxylate groups, and two nitro groups. The RbO 6 N polyhedron comprises the two bridging water molecules, one monodentate amine N-atom donor, one carboxyl O-atom donor and three O-atom donors from nitro groups (one from the chelate bridge). The extension of the dinuclear unit gives a three-dimensional polymeric structure which is stabilized by both intra-and intermolecular amine N-HÁ Á ÁO and water O-HÁ Á ÁO hydrogen bonds to carboxyl and water O-atom acceptors, as well as a number of inter-ring -interactions [minimum centroid-centroid separation = 3.364 (2) Å ]. The title salt is isostructural with the analogous caesium salt.

Crystal structures of the 1:1 salts of 2-amino-4-nitrobenzoate with each of (2-hydroxyethyl)dimethylazanium, tert-butyl(2-hydroxyethyl)azanium and 1,3-dihydroxy-2-(hydroxymethyl)propan-2-aminium

“…Despite being tetramorphic (Wardell & Tiekink, 2011;, readily forming co-crystals (Wardell & Tiekink, 2011) and providing systematic series of crystals of alkali metal, e.g. Na + , K + (Smith, 2013), Rb + (Smith, 2014a) and Cs + (Smith & Wermuth, 2011), and ammonium salts, see below, studies of the relatively small benzoic acid derivative, 2-amino-4-nitrobenzoic acid, are still comparatively limited. Most crystallographic investigations of the acid have focused upon an evaluation of the hydrogen-bonding propensities occurring in derived ammonium salts of the 2-amino-4-nitrobenzoate anion.…”

Hydrazinium 2-amino-4-nitrobenzoate dihydrate: crystal structure and Hirshfeld surface analysis

“…These are either alkali metal salts, i.e. Na + , K + (Smith, 2013), Rb + (Smith, 2014a) and Cs + (Smith & Wermuth, 2011), or are ammonium salts, as discussed below. Herein, the crystal and molecular structures of (I) are described along with an evaluation of its Hirshfeld surface.…”

Two dialkylammonium salts of 2-amino-4-nitrobenzoic acid: crystal structures and Hirshfeld surface analysis

“…Thus, the structures of alkali metal salts, i.e. Na + , K + (Smith, 2013), Rb + (Smith, 2014a) and Cs + (Smith & Wermuth, 2011) have been described along with a number of ammonium salts, i.e. with NH 4 , as a hydrate (Smith, 2014b), dicyclohexylammonium (Smith et al, 2004), guanidinium, as a hydrate (Smith et al, 2007), morpholinium (Smith & Lynch, 2016) and ethylenediammonium, as a dihydrate (Smith et al, 2002).…”