Di­ethyl­ammonium di­hydrogen orthophosphate

Peter Held

doi:10.1107/S1600536814000464

. 2014 Jan 11;70(Pt 2):o129. doi: 10.1107/S1600536814000464

Diethylammonium dihydrogen orthophosphate

Peter Held ^a,^*

PMCID: PMC3998295 PMID: 24764856

Abstract

In the title molecular salt, [NH₂(CH₂CH₃)₂][H₂PO₄], two unique types of cations and anions, which are configurationally very similar, are present in the asymmetric unit. Both ions form sheets approximately parallel to (-1-1) linked by weak hydrogen bonds. The interconnection within and between the sheets is reinforced by O—H⋯O and N—H⋯O hydrogen bonds involving the tetrahedral H₂PO₄ anions and the ammonium groups.

Related literature

For preparative details, see: Hanna et al. (1999 ▶). For related structures, see: Averbuch-Pouchot et al. (1987 ▶); Held (2003 ▶). graphic file with name e-70-0o129-scheme1.jpg

Experimental

Crystal data

C₄H₁₂N⁺·H₂PO₄ ⁻
M _r = 171.13
Triclinic,
a = 8.3643 (6) Å
b = 8.8308 (15) Å
c = 11.6446 (12) Å
α = 88.219 (10)°
β = 83.649 (7)°
γ = 79.700 (7)°
V = 841.00 (18) Å³
Z = 4
Mo Kα radiation
μ = 0.29 mm⁻¹
T = 295 K
0.30 × 0.28 × 0.26 mm

Data collection

Nonius MACH3 diffractometer
Absorption correction: ψ scan (North et al., 1968 ▶) T _min = 0.858, T _max = 0.998
10831 measured reflections
5096 independent reflections
3164 reflections with I > 2σ(I)
R _int = 0.037
3 standard reflections every 100 reflections intensity decay: −6.3%

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.119
S = 0.98
5096 reflections
181 parameters
H-atom parameters constrained
Δρ_max = 0.37 e Å⁻³
Δρ_min = −0.39 e Å⁻³

Data collection: CAD-4 (Enraf–Nonius, 1989 ▶); cell refinement: CAD-4; data reduction: WinGX (Farrugia, 2012 ▶); program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ATOMS (Dowty, 2002 ▶) and ORTEP-3 for Windows (Farrugia, 2012 ▶)’; software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536814000464/wm2794sup1.cif

e-70-0o129-sup1.cif^{(23.3KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536814000464/wm2794Isup2.hkl

e-70-0o129-Isup2.hkl^{(249.6KB, hkl)}

CCDC reference: http://scripts.iucr.org/cgi-bin/cr.cgi?rm=csd&csdid=980665

Additional supporting information: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O13—H13⋯O21ⁱ	0.82	1.78	2.5851 (19)	166
O14—H14⋯O12ⁱⁱ	0.82	1.83	2.6058 (19)	158
O24—H24⋯O22ⁱⁱⁱ	0.82	1.95	2.585 (2)	133
O23—H23⋯O11ⁱ	0.82	1.84	2.620 (2)	158
N1—H1A⋯O22^iv	0.90	1.88	2.779 (2)	174
N1—H1B⋯O21^v	0.90	1.87	2.769 (2)	177
N2—H2A⋯O11^vi	0.90	1.87	2.714 (2)	155
N2—H2B⋯O12	0.90	1.91	2.795 (2)	168

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) ; (v) ; (vi) .

supplementary crystallographic information

1. Comment

In the course of a systematic search for new 'double salts' of simple secondary amines and monovalent cations of various inorganic acids (Averbuch-Pouchot et al., 1987), the new structure of (C₂N₂H₁₀)Li₂(SO₄)₂ was described (Held, 2003). In continuation of these studies, sulfuric acid has been replaced with phosphoric acid in order to get an analogous lithium compound with a tetrahedral phosphoric unit. Moreover, ethylenediamine has been replaced with diethylamine. Surprisingly, lithium was not incorporated in the solid product and only the title compound, [NH₂(CH₂CH₃)₂]⁺[H₂PO₄]^-, was finally obtained, the crystal structure of which is reported herein.

The crystal structure of [NH₂(CH₂CH₃)₂]⁺[H₂PO₄]^- consists of diethylammonium cations, NH₂(CH₂CH₃)₂⁺, and dihydrogen orthophosphate anions, H₂PO₄^- (Fig. 1). The ions form sheets approximately parallel to (112). The interconnection within and between the sheets is reinforced by a hydrogen bonding system between the tetrahedral dihydrogen orthophosphate groups on one hand and between the ammonium function and the H₂PO₄^- units on the other (Figs. 2,3; Table 1).

2. Experimental

The title compound was obtained by reaction of an aqueous solution of lithium dihydrogenposphate with diethylammine in a stoichiometric ratio 1:1 (Hanna et al., 1999). The solution was kept at room temperature by cooling. The title compound crystallized by slow evaporation of the solvent at room temperature in form of colourless crystals with dimensions up to 4 mm within a few days.

Differential scanning calorimetry with a PerkinElmer DSC7 device in the temperature range from 183 K up to 293 K showed no significant feature.