Bis(2-hydroxy­ethyl­ammonium) oxalate

In bis(2-hydroxy­ethyl­ammonium) oxalate, 2C₂H₈NO⁺·C₂O₄^2-, hydrogen bonds involving the hydroxy and ammonium groups connect the carboxyl O atoms of the oxalate anion into a three-dimensional network structure.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.041
• wR factor = 0.114
• Data-to-parameter ratio = 12.5

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



ABSMU_01  Alert C The ratio of given/expected absorption coefficient lies
          outside the range 0.99 <> 1.01
          Calculated value of mu =     0.134
          Value of mu given      =     0.130

PLAT_369  Alert C Long   C(sp2)-C(sp2) Bond  C(3)   -   C(3)a  =       1.56 Ang.


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 2 Alert Level C = Please check

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S1. Comment

Double salts with small-length alkylammonium cations are of interest because of their optical (Jayasree et al., 1996; Mahadevan Pillai et al., 1997, 1998), ferroelectric, ferroelastic (Kirpichnikova et al., 1990; Vlokh et al., 1991a,b) and structural (Bator et al., 1998; Kearley, 1983) properties, these compounds often exhibiting several phase transitions at lower temperature. The divalent metal 2-ethanolammonium (Jordanovska & Trojko, 1993) and trivalent metal bis- and tris(2-ethanol)ammonium sulfates (Jordanovska et al., 1996) exist as double salts; however, the reaction of M^II oxalates (M = Mn, Co, Ni, Cu, Zn and Cd) yields only 2-ethanolamine adducts (Jordanovska & Trojko, 1995).

In our hands, the synthesis of the cadmium oxalate adduct gave only bis(2-ethanolammonium) oxalate. The structures of some ammonium oxalates have been described recently (Krishnakumar et al., 1998; Paixao et al., 1999). The title ammonium oxalate, (I), displays no unusual features; the C—C bond [1.559 (5) Å] in the oxalate anion is also characteristically long. Its ammonium unit is engaged in three hydrogen-bonding interactions, whereas the hydroxyl unit is engaged in one hydrogen-bonding interaction.

S2. Experimental

An aqueous solution of oxalic acid was neutralized with aqueous ethanolamine to pH 8. The solution was concentrated by evaporating the water. Crystals deposited after cooling the solution to room temperature and these were washed with ethanol and air-dried. A yellow form of the compound was obtained in the attempt to prepare the 2-ethanolamine complex of cadmium(II) oxalate (Jordanovska & Trojko, 1995) by refluxing cadmium oxalate and aqueous 2-ethanolamine in chloroform.

Computing details

Data collection: CAD-4 EXPRESS (Enraf-Nonius, 1994); cell refinement: CELDIM in CAD-4 Software (Enraf-Nonius, 1989); data reduction: XCAD4 (Harms, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. ORTEPII (Johnson, 1976) plot with displacement ellipsoids at the 50% probability level.
	Fig. 2. Hydrogen-bonding interactions of the anion.

Bis(2-hydroxyethylammonium) oxalate

Crystal data

2C2H8NO^+·C2O4^2^−	F(000) = 456
Mr = 212.21	Dx = 1.502 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 17.473 (5) Å	Cell parameters from 25 reflections
b = 5.916 (2) Å	θ = 6.8–18.1°
c = 10.346 (3) Å	µ = 0.13 mm^−1
β = 118.69 (2)°	T = 298 K
V = 938.2 (5) Å^3	Block, colorless
Z = 4	0.20 × 0.10 × 0.05 mm

Data collection

Enraf-Nonius CAD-4 diffractometer	Rint = 0.019
Radiation source: fine-focus sealed tube	θmax = 25.0°, θmin = 2.7°
Graphite monochromator	h = −20→18
ω–2θ scans	k = 0→7
872 measured reflections	l = 0→12
822 independent reflections	3 standard reflections every 120 min
550 reflections with I > 2σ(I)	intensity decay: 7%

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.114	H-atom parameters constrained
S = 1.01	w = 1/[σ^2(Fo^2) + (0.0543P)^2 + 0.712P] where P = (Fo^2 + 2Fc^2)/3
822 reflections	(Δ/σ)max < 0.001
66 parameters	Δρmax = 0.24 e Å^−3
0 restraints	Δρmin = −0.23 e Å^−3

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	0.1537 (1)	0.6481 (3)	0.0628 (2)	0.0338 (5)
O2	0.0660 (1)	0.5873 (3)	0.2176 (2)	0.0332 (5)
O3	0.0482 (1)	0.2157 (3)	0.1781 (2)	0.0280 (5)
N1	0.0888 (1)	1.1050 (4)	−0.0510 (2)	0.0271 (5)
C1	0.1810 (2)	1.0305 (5)	0.0172 (3)	0.0289 (7)
C2	0.2000 (2)	0.8480 (5)	0.1294 (3)	0.0296 (6)
C3	0.0330 (2)	0.4006 (4)	0.2193 (3)	0.0215 (6)
H1	0.1246	0.6102	0.1022	0.051*
H1a	0.0539	0.9873	−0.0933	0.041*
H1b	0.0792	1.2100	−0.1187	0.041*
H1c	0.0779	1.1625	0.0180	0.041*
H1d	0.2189	1.1587	0.0642	0.035*
H1e	0.1934	0.9747	−0.0589	0.035*
H2a	0.2621	0.8163	0.1800	0.036*
H2b	0.1839	0.9000	0.2019	0.036*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.041 (1)	0.029 (1)	0.038 (1)	−0.005 (1)	0.025 (1)	−0.002 (1)
O2	0.044 (1)	0.022 (1)	0.046 (1)	−0.006 (1)	0.031 (1)	−0.003 (1)
O3	0.032 (1)	0.023 (1)	0.033 (1)	0.000 (1)	0.019 (1)	−0.005 (1)
N1	0.035 (1)	0.021 (1)	0.029 (1)	0.001 (1)	0.018 (1)	0.000 (1)
C1	0.032 (2)	0.027 (2)	0.035 (2)	−0.005 (1)	0.021 (1)	−0.002 (1)
C2	0.027 (1)	0.033 (2)	0.027 (1)	0.000 (1)	0.012 (1)	0.000 (1)
C3	0.024 (1)	0.018 (1)	0.020 (1)	−0.001 (1)	0.009 (1)	0.000 (1)

Geometric parameters (Å, º)

O1—C2	1.412 (3)	N1—H1a	0.890
O2—C3	1.250 (3)	N1—H1b	0.890
O3—C3	1.248 (3)	N1—H1c	0.890
N1—C1	1.481 (3)	C1—H1d	0.970
C1—C2	1.501 (4)	C1—H1e	0.970
C3—C3^i	1.559 (5)	C2—H2a	0.970
O1—H1	0.820	C2—H2b	0.970
N1—C1—C2	111.6 (2)	H1b—N1—H1c	109.5
O1—C2—C1	111.3 (2)	N1—C1—H1d	109.3
O3—C3—O2	126.4 (2)	C2—C1—H1d	109.3
O3—C3—C3^i	117.4 (2)	N1—C1—H1e	109.3
O2—C3—C3^i	116.2 (2)	C2—C1—H1e	109.3
C2—O1—H1	109.5	H1d—C1—H1e	108.0
C1—N1—H1a	109.5	O1—C2—H2a	109.4
C1—N1—H1b	109.5	C1—C2—H2a	109.4
H1a—N1—H1b	109.5	O1—C2—H2b	109.4
C1—N1—H1c	109.5	C1—C2—H2b	109.4
H1a—N1—H1c	109.5	H2a—C2—H2b	108.0
N1—C1—C2—O1	65.8 (3)

Symmetry code: (i) −x, y, −z+1/2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O2	0.82	1.92	2.720 (3)	167
N1—H1a···O3^ii	0.89	1.97	2.835 (3)	163
N1—H1b···O2^iii	0.89	2.00	2.878 (3)	171
N1—H1c···O3^iv	0.89	1.98	2.857 (3)	167

Symmetry codes: (ii) −x, −y+1, −z; (iii) x, −y+2, z−1/2; (iv) x, y+1, z.