Ethyl­enediaminium hemioxalate thio­cyanate

In the title compound, C₂H₁₀N₂²⁺·0.5(C₂O₄)²⁻·NCS⁻, the ethyl­enediaminium dication adopts a (+)-synclinal conformation with an N—C—C—N torsion angle of 62.64 (15)°. The oxalate dianion lies across an inversion centre. In the crystal structure, the ions are linked through N—H...N, N—H...O and C—H...S hydrogen bonds, leading to the formation of a three-dimensional network.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.034
• wR factor = 0.095
• Data-to-parameter ratio = 19.9

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT042_ALERT_1_C Calc. and Reported MoietyFormula Strings  Differ          ?
PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L=  0.600          6

Alert level G
FORMU01_ALERT_1_G  There is a discrepancy between the atom counts in the
            _chemical_formula_sum and _chemical_formula_moiety. This is
            usually due to the moiety formula being in the wrong format.
            Atom count from _chemical_formula_sum:   C4 H10 N3 O2 S1
            Atom count from _chemical_formula_moiety:H10 N3
PLAT154_ALERT_1_G The su's on the Cell Angles are Equal  (x 10000)        500 Deg.

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   2 ALERT level C = Check and explain
   2 ALERT level G = General alerts; check

   3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Aqueous solution of ethylenediamine and oxalic acid regardless of their stiochiometric ratio was reported to give ethylenediammonium bis(monohydrogen oxalate) monohydrate (II) (Barnes et al., 1998). However, the same reaction but in the presence of ammonium thiocyanate was found to give an ethylenediammonium hemioxalate thiocynate, the title compound, (I, Fig.1), indicating that the oxalic acid has been completely deprotonated.

The centrosymmetric oxalate anion is planar as commonly observed in many oxalate salts (Tang et al., 2009; Seidel et al., 2008). The C—O bond lengths are quite similar indicating a delocalisation of electron about the O—C—O bond as observed in (II) and N-[2-(2-chlorophenyl)-2-hydroxyethyl]-propann-2-aminium hemioxalate (III) (Tang et al., 2009). The ethylenediaminium ion in this salt is not planar but twisted with a N3—C3—C4—N2 torsion angle of 62.64 (15)°. In compound (II), and ethylenediammonium pyridine-2,5-dicarboxylate dihydrate (IV) (Smith et al., 2006), the ethylenediammonium cation is centrosymmetric and has an extended conformation with a N—C—C—N torsion angle of 180°. The thiocyanate anion is linear. The bond lengths and angles are in normal ranges (Allen et al., 1987) and comparable with those in (II), (III) and (IV).

In the crystal structure, the molecules are linked by N—H···N, N—H···O and C—H···S hydrogen bonds (Table 1) forming a three-dimemsional network (Fig. 2).

Related literature

For related structures, see: Barnes et al. (1998); Smith et al. (2006); Seidel et al. (2008); Tang et al. (2009). For bond-length data, see: Allen et al. (1987).

S2. Experimental

An aqueous solution (10 ml) of ammonium thiocyanate (0.152 g, 2 mmol) was added into a beaker containing oxalate acid (0.126 g, 1 mmol) and ethylenediamine (2 mmol) in distilled water (40 ml). After one week of evaporation at room temperature, colourless crystals of the title compound were obtained (yield 92%; m.p. 457.1-458.3 K).

S3. Refinement

After their location in a difference map, the methylene and ammonium H-atoms were positioned geometrically [N–H = 0.89 Å and C–H = 0.97 Å] and allowed to ride on the parent atoms, with U_iso(H) = 1.2U_eq(C,N). A rotating group model was used for the ammonium group.

Computing details

Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT (Siemens, 1996); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008), PARST (Nardelli, 1995) and PLATON (Spek, 2009).

Figures

	Fig. 1. The asymmetric unit of the title compound. Displacement ellipsoids are drawn at the 50% probability level. Unlabelled atoms in the dianion are related to other labelled atoms in it by the symmetry operation (1 - x, -y, 1 - z).
	Fig. 2. Packing diagram of the title compound, viewed down the b axis. Hydrogen bonds are shown as dashed lines.

Ethylenediaminium hemioxalate thiocyanate

Crystal data

C2H10N2^2+·0.5C2O4^2^−·NCS^−	Z = 2
Mr = 164.21	F(000) = 174
Triclinic, P1	Dx = 1.452 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.4044 (19) Å	Cell parameters from 3525 reflections
b = 6.6199 (19) Å	θ = 2.2–28.3°
c = 9.377 (3) Å	µ = 0.38 mm^−1
α = 80.799 (5)°	T = 298 K
β = 81.179 (5)°	Block, colourless
γ = 74.452 (5)°	0.43 × 0.41 × 0.35 mm
V = 375.5 (2) Å^3

Data collection

Bruker SMART APEX CCD area-detector diffractometer	1867 independent reflections
Radiation source: fine-focus sealed tube	1718 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.017
Detector resolution: 83.66 pixels mm^-1	θmax = 28.3°, θmin = 2.2°
ω scan	h = −8→8
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	k = −8→8
Tmin = 0.854, Tmax = 0.879	l = −12→12
5091 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.034	H-atom parameters constrained
wR(F^2) = 0.095	w = 1/[σ^2(Fo^2) + (0.0453P)^2 + 0.1426P] where P = (Fo^2 + 2Fc^2)/3
S = 1.06	(Δ/σ)max = 0.001
1867 reflections	Δρmax = 0.51 e Å^−3
94 parameters	Δρmin = −0.52 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.41 (2)

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

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

	x	y	z	Uiso*/Ueq
O1	0.23176 (14)	0.09074 (15)	0.45456 (11)	0.0325 (2)
O2	0.41295 (15)	0.23958 (14)	0.57426 (10)	0.0309 (2)
C1	0.39758 (18)	0.09557 (17)	0.50846 (12)	0.0232 (2)
S1	0.76420 (7)	0.30131 (6)	0.20864 (5)	0.04886 (18)
N1	0.7143 (2)	0.7005 (2)	0.04926 (17)	0.0521 (4)
C2	0.7374 (2)	0.5334 (2)	0.11335 (15)	0.0362 (3)
N2	0.2850 (2)	0.94792 (18)	0.17891 (12)	0.0346 (3)
H2A	0.2477	1.0605	0.1135	0.041*
H2B	0.4190	0.8736	0.1513	0.041*
H2C	0.2819	0.9898	0.2650	0.041*
N3	0.18949 (17)	0.64628 (17)	0.44290 (12)	0.0287 (2)
H3A	0.2241	0.5223	0.4981	0.034*
H3B	0.0574	0.7188	0.4760	0.034*
H3C	0.2868	0.7191	0.4460	0.034*
C3	0.1898 (2)	0.6105 (2)	0.29020 (15)	0.0316 (3)
H3D	0.0877	0.5264	0.2881	0.038*
H3E	0.3340	0.5311	0.2548	0.038*
C4	0.1284 (2)	0.8139 (2)	0.19058 (15)	0.0356 (3)
H4A	0.1213	0.7813	0.0945	0.043*
H4B	−0.0157	0.8932	0.2262	0.043*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0227 (4)	0.0324 (5)	0.0425 (5)	−0.0015 (3)	−0.0087 (4)	−0.0100 (4)
O2	0.0302 (5)	0.0241 (4)	0.0388 (5)	−0.0025 (3)	−0.0072 (4)	−0.0091 (4)
C1	0.0220 (5)	0.0207 (5)	0.0251 (5)	−0.0035 (4)	−0.0018 (4)	−0.0013 (4)
S1	0.0510 (3)	0.0346 (2)	0.0483 (3)	0.00328 (17)	0.00029 (18)	0.00231 (16)
N1	0.0485 (8)	0.0464 (8)	0.0511 (8)	−0.0062 (6)	−0.0010 (6)	0.0098 (6)
C2	0.0303 (6)	0.0399 (7)	0.0327 (7)	−0.0011 (5)	−0.0009 (5)	−0.0037 (5)
N2	0.0409 (6)	0.0288 (5)	0.0300 (5)	−0.0051 (5)	−0.0044 (4)	0.0023 (4)
N3	0.0267 (5)	0.0258 (5)	0.0341 (6)	−0.0077 (4)	−0.0060 (4)	−0.0002 (4)
C3	0.0323 (6)	0.0261 (6)	0.0353 (7)	−0.0050 (5)	−0.0018 (5)	−0.0067 (5)
C4	0.0396 (7)	0.0336 (7)	0.0332 (7)	−0.0053 (5)	−0.0116 (5)	−0.0031 (5)

Geometric parameters (Å, º)

O1—C1	1.2539 (15)	N3—C3	1.4879 (18)
O2—C1	1.2474 (15)	N3—H3A	0.89
C1—C1^i	1.568 (2)	N3—H3B	0.89
S1—C2	1.6295 (16)	N3—H3C	0.89
N1—C2	1.155 (2)	C3—C4	1.5054 (19)
N2—C4	1.4890 (19)	C3—H3D	0.97
N2—H2A	0.89	C3—H3E	0.97
N2—H2B	0.89	C4—H4A	0.97
N2—H2C	0.89	C4—H4B	0.97
O2—C1—O1	125.46 (11)	H3A—N3—H3C	109.5
O2—C1—C1^i	117.42 (13)	H3B—N3—H3C	109.5
O1—C1—C1^i	117.12 (13)	N3—C3—C4	112.50 (11)
N1—C2—S1	177.95 (14)	N3—C3—H3D	109.1
C4—N2—H2A	109.5	C4—C3—H3D	109.1
C4—N2—H2B	109.5	N3—C3—H3E	109.1
H2A—N2—H2B	109.5	C4—C3—H3E	109.1
C4—N2—H2C	109.5	H3D—C3—H3E	107.8
H2A—N2—H2C	109.5	N2—C4—C3	113.05 (11)
H2B—N2—H2C	109.5	N2—C4—H4A	109.0
C3—N3—H3A	109.5	C3—C4—H4A	109.0
C3—N3—H3B	109.5	N2—C4—H4B	109.0
H3A—N3—H3B	109.5	C3—C4—H4B	109.0
C3—N3—H3C	109.5	H4A—C4—H4B	107.8
N3—C3—C4—N2	62.64 (15)

Symmetry code: (i) −x+1, −y, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2B···N1	0.89	2.11	2.986 (2)	169
N3—H3A···O2	0.89	2.02	2.8685 (17)	158
C3—H3E···S1	0.97	2.77	3.7294 (18)	169
N2—H2A···N1^ii	0.89	2.05	2.899 (2)	159
N2—H2C···O1^iii	0.89	1.95	2.8337 (18)	172
N3—H3B···O1^iv	0.89	2.02	2.9078 (17)	174
N3—H3C···O1^iii	0.89	2.40	3.0465 (18)	129
N3—H3C···O2^v	0.89	1.99	2.8189 (18)	154
C4—H4B···S1^vi	0.97	2.68	3.4495 (18)	136

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