Anhydrous guanidinium hydrogen fumarate: a two-dimensional hydrogen-bonded network structure

The title compound, CH₆N₃⁺·C₄H₃O₄^-, forms a two-dimensional hydrogen-bonded network structure. The guanidinium cations lie across crystallographic mirror planes while the hydrogen fumarate anions have inversion symmetry with the acid proton 50% disordered over the two carboxylate groups.

Key indicators

• Single-crystal X-ray study
• T = 297 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.040
• wR factor = 0.143
• Data-to-parameter ratio = 12.2

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          2
              C H6 N3

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

   1 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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Computing details

Data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1999); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: TEXSAN for Windows (Molecular Structure Corporation, 1999); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: PLATON.

guanidinium hydrogen fumarate

Crystal data

CH6N3^+·C4H3O4^−	F(000) = 184
Mr = 175.15	Dx = 1.525 Mg m^−3
Monoclinic, P21/m	Melting point = 495–497 K
Hall symbol: -P 2yb	Mo Kα radiation, λ = 0.71073 Å
a = 5.4995 (12) Å	Cell parameters from 25 reflections
b = 18.842 (5) Å	θ = 12.9–17.5°
c = 3.6943 (11) Å	µ = 0.13 mm^−1
β = 94.83 (2)°	T = 297 K
V = 381.45 (17) Å^3	Plate, colourless
Z = 2	0.45 × 0.32 × 0.12 mm

Data collection

Rigaku AFC-7R diffractometer	Rint = 0.025
Radiation source: rotating anode	θmax = 27.5°, θmin = 3.7°
Graphite monochromator	h = −7→7
ω–2θ scans	k = 0→24
1088 measured reflections	l = −4→2
905 independent reflections	3 standard reflections every 150 min
637 reflections with I > 2σ(I)	intensity decay: 2.4%

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)] = 0.040	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.143	H atoms treated by a mixture of independent and constrained refinement
S = 0.94	w = 1/[σ^2(Fo^2) + (0.1P)^2 + 0.0662P] where P = (Fo^2 + 2Fc^2)/3
905 reflections	(Δ/σ)max < 0.001
74 parameters	Δρmax = 0.17 e Å^−3
0 restraints	Δρmin = −0.26 e Å^−3

Special details

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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	Occ. (<1)
O1A	0.4303 (2)	0.06095 (6)	0.9276 (3)	0.0354 (4)
O1B	0.1293 (2)	0.12591 (6)	0.6682 (4)	0.0421 (4)
C1	0.2246 (3)	0.06799 (8)	0.7310 (4)	0.0275 (4)
C2	0.1086 (3)	0.00117 (8)	0.5855 (4)	0.0293 (5)
N11	0.3626 (4)	0.25000	0.9877 (7)	0.0390 (7)
N21	0.6905 (3)	0.18881 (9)	1.2450 (6)	0.0494 (6)
C11	0.5827 (5)	0.25000	1.1591 (7)	0.0319 (7)
H2	0.20490	−0.04000	0.60240	0.0300*
H1A	0.480 (9)	0.018 (2)	0.942 (12)	0.039 (12)*	0.500
H11	0.295 (5)	0.2102 (14)	0.903 (6)	0.055 (7)*
H21A	0.839 (6)	0.1885 (16)	1.380 (8)	0.068 (8)*
H21B	0.610 (5)	0.1502 (15)	1.164 (8)	0.066 (8)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1A	0.0258 (6)	0.0247 (7)	0.0518 (8)	−0.0001 (4)	−0.0192 (5)	−0.0027 (5)
O1B	0.0364 (7)	0.0226 (6)	0.0626 (9)	0.0038 (5)	−0.0227 (6)	−0.0041 (5)
C1	0.0210 (7)	0.0258 (8)	0.0341 (8)	−0.0006 (5)	−0.0071 (6)	−0.0021 (6)
C2	0.0244 (8)	0.0222 (7)	0.0393 (9)	0.0012 (5)	−0.0099 (6)	−0.0031 (6)
N11	0.0368 (11)	0.0247 (10)	0.0514 (13)	0.0000	−0.0195 (10)	0.0000
N21	0.0423 (10)	0.0307 (9)	0.0702 (12)	0.0069 (7)	−0.0244 (9)	−0.0003 (7)
C11	0.0305 (11)	0.0266 (11)	0.0366 (12)	0.0000	−0.0088 (9)	0.0000

Geometric parameters (Å, º)

O1A—C1	1.299 (2)	N11—H11	0.88 (3)
O1B—C1	1.2244 (19)	N21—H21A	0.92 (3)
O1A—H1A	0.85 (4)	N21—H21B	0.89 (3)
N11—C11	1.318 (4)	C1—C2	1.491 (2)
N21—C11	1.323 (2)	C2—C2^ii	1.304 (2)
N11—H11^i	0.88 (3)	C2—H2	0.9400
C1—O1A—H1A	113 (3)	O1B—C1—C2	121.40 (15)
C11—N11—H11	120.9 (18)	O1A—C1—O1B	122.40 (15)
H11—N11—H11^i	116 (2)	C1—C2—C2^ii	123.35 (15)
C11—N11—H11^i	120.9 (17)	C1—C2—H2	117.00
H21A—N21—H21B	125 (3)	C2^ii—C2—H2	120.00
C11—N21—H21B	115.6 (18)	N21—C11—N21^i	121.3 (2)
C11—N21—H21A	119.7 (19)	N11—C11—N21	119.35 (13)
O1A—C1—C2	116.20 (13)	N11—C11—N21^i	119.35 (13)
O1B—C1—C2—C2^ii	−6.7 (2)	C1—C2—C2^ii—C1^ii	179.98 (16)
O1A—C1—C2—C2^ii	173.03 (15)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1A—H1A···O1A^iii	0.85 (4)	1.63 (4)	2.4658 (18)	166 (5)
N11—H11···O1B	0.88 (3)	1.99 (3)	2.873 (2)	174 (2)
N21—H21A···O1B^iv	0.92 (3)	2.19 (3)	3.006 (2)	148 (3)
N21—H21B···O1A	0.89 (3)	2.10 (3)	2.991 (2)	175 (3)
C2—H2···O1A^iii	0.94	2.57	3.204 (2)	125

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