Charge-assisted hydrogen bonding in three diaminobenzene salts

Abstract

Hydrogen-bonding interactions play an important role in the rational design of crystal systems with desirable architectures. The crystal structures of benzene-1,2-diaminium sulfate sesquihydrate, C6H20N2 2+·SO4 2−·1.5H2O, (1), benzene-1,3-diaminium tetrachloridozincate(II), (C6H20N2)[ZnCl4], (3), and 3-aminoanilinium perchlorate, C6H9N2 +·ClO4 −, (4), are reported. Hydrated salt (1) is a polymorph (space group C2/c) of a previously reported [Anderson et al. (2011). Cryst. Growth Des. 11, 4904–4919] crystalline modification of salt (2) (space group P21/c). The contents of the asymmetric unit of (2) are twice that of (1). In each, the extended structures exhibit hydrogen bonds, resulting in chains of ions and hydrogen-bonded rings with an R 4 4(8) motif involving water molecules. Hirshfeld surface analysis shows that a significant difference between the two is the degree of C...C interaction. Salt (3) exhibits an extended structure having hydrogen-bonded rings and parallel benzene rings, with a centroid-to-centroid separation of 3.860 (2) Å. Salt (4) displays a three-dimensional superstructure that results from linked planes of ions joined by an extensive hydrogen-bonding network involving N—H...O, N—H...N and C—H...π interactions. The cation–anion and N—H...N interaction energies in (4), determined using density functional theory (DFT), show significantly stronger aminium–perchlorate than amine–perchlorate interactions.

Hydrogen bonding in two benzene-1,2-diaminium pyridine-2-carboxylate salts and a cocrystal of benzene-1,2-diamine and benzoic acid

“…The results suggest that the slight difference in basicities of the two diamines does not play a major role in determining the strengths of these hydrogen bonds. These values are less than that of À665 kJ mol À1 found for the charge-assisted N-HÁ Á ÁO hydrogen bonds in 3-aminoanilinium perchlorate (Zick & Geiger, 2018) and are close to the values found for the methylammoniumÁ Á ÁCl À and methylamineÁ Á ÁCl À energies, i.e. À507 and À413 kJ mol À1 , respectively (Defazio et al, 2005).…”

“…two N-H donors and one N-atom acceptor) and À42.09 kJ mol À1 for a four-membered ring with a bifurcated hydrogen bond (a 4-pyridone donor and two fused pyridine rings as acceptors). A value of À94.9 kJ mol À1 obtained using the M06-2X functional has been reported for an N-HÁ Á ÁN interaction between two benzene-1,3-diaminium cations (Zick & Geiger, 2018) and a value of À79.5 kJ mol À1 was reported for [H 2 NÁ Á ÁHÁ Á ÁNH 3 ] + (Steiner, 2002).…”

“…Using SPARTAN'16 (Wavefunction, 2016) and the M06-2X functional, as described in Section 2.3, a value of À56.0 kJ mol À1 was obtained for the R 2 2 (9) ring interactions and a value of À20.6 kJ for the N-HÁ Á ÁO interaction in the R 2 4 (8) ring. The M06 suite of density functionals are reported to outperform B3LYP for dispersion and ionic hydrogenbonding interactions (Walker et al, 2013;Zhao & Truhlar, 2008;Zick & Geiger, 2018). Partial packing diagram of (3), showing the linked chains parallel to [001].…”

“…We recently reported the preparation, structural characterization and calculated interaction energies of several protonated benzenediamines with inorganic anions (Zick & Geiger, 2018). Herein, we explore the structures of two isostructural salts, namely, benzene-1,2-diaminium bis(pyridine-2-carboxylate), (1), and 4,5-dimethylbenzene-1,2-diaminium bis(pyridine-2-carboxylate), (2).…”

DL-Piperidinium-2-carboxylate bis(hydrogen peroxide): unusual hydrogen-bonded peroxide chains

“…It is significant that such chains and HOOHÁ Á ÁOHOH hydrogen bonds were not observed previously in the structures of aliphatic -amino acid peroxosolvates. The reason for this is that charge-assisted HOOHÁ Á Á À O 2 C bonds are energetically preferable to HOOHÁ Á ÁOHOH interactions (Jesus & Redinha, 2011;Zick & Geiger, 2018…”