Creatininium hydrogen oxalate monohydrate

In the title compound, C₄H₈N₃O⁺·C₂HO₄⁻·H₂O, the asymmetric unit comprises one creatinium cation, one hydrogen oxalate anion and one water mol­ecule. All non-H atoms lie on a crystallographic mirror plane and both the cation skeleton and the anion are therefore totally planar. In the crystal packing, an extended network of O—H...O and N—H...O hydrogen-bonding inter­actions results in the formation of two-dimensional sheets parallel to the ac plane.

Key indicators

• Single-crystal X-ray study
• T = 294 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.034
• wR factor = 0.097
• Data-to-parameter ratio = 8.5

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT088_ALERT_3_C Poor Data / Parameter Ratio ....................       8.48
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       3.76
PLAT369_ALERT_2_C Long   C(sp2)-C(sp2) Bond  C9     -   C10    ...       1.55 Ang.

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:   C6 H11 N3 O6
            Atom count from _chemical_formula_moiety:C6 H14 N3 O6

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

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

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Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg & Putz, 2005) and SHELXTL/PC (Sheldrick, 1990); software used to prepare material for publication: SHELXL97.

Creatininium hydrogen oxalate monohydrate

Crystal data

C4H8N3O^+·C2HO4^−·H2O	F(000) = 464
Mr = 221.18	Dx = 1.514 Mg m^−3
Orthorhombic, Pnma	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2n	Cell parameters from 5792 reflections
a = 9.1728 (7) Å	θ = 2.5–27.8°
b = 6.3520 (5) Å	µ = 0.14 mm^−1
c = 16.6567 (12) Å	T = 294 K
V = 970.51 (13) Å^3	Block, colourless
Z = 4	0.21 × 0.18 × 0.10 mm

Data collection

Bruker SMART APEX CCD area-detector diffractometer	895 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.018
Graphite monochromator	θmax = 25.0°, θmin = 2.5°
ω scans	h = −10→10
6481 measured reflections	k = −7→7
933 independent reflections	l = −19→19

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)] = 0.034	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.098	H atoms treated by a mixture of independent and constrained refinement
S = 1.11	w = 1/[σ^2(Fo^2) + (0.0614P)^2 + 0.1548P] where P = (Fo^2 + 2Fc^2)/3
933 reflections	(Δ/σ)max < 0.001
110 parameters	Δρmax = 0.18 e Å^−3
0 restraints	Δρmin = −0.23 e Å^−3

Special details

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

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
C2	0.16471 (18)	0.2500	0.54778 (9)	0.0342 (4)
C4	0.34887 (18)	0.2500	0.63692 (10)	0.0389 (4)
C5	0.20624 (19)	0.2500	0.68254 (10)	0.0402 (4)
H5A	0.1971	0.1255	0.7159	0.048*	0.50
H5B	0.1971	0.3745	0.7159	0.048*	0.50
C7	−0.05704 (19)	0.2500	0.63194 (11)	0.0435 (4)
H7A	−0.0789	0.3332	0.6785	0.065*	0.50
H7B	−0.0899	0.1082	0.6403	0.065*	0.50
H7C	−0.1056	0.3086	0.5860	0.065*	0.50
N1	0.09882 (15)	0.2500	0.61829 (8)	0.0368 (4)
N3	0.31220 (16)	0.2500	0.55718 (8)	0.0376 (4)
H3N	0.374 (3)	0.2500	0.5171 (15)	0.057 (6)*
N6	0.10137 (17)	0.2500	0.47779 (9)	0.0429 (4)
H6A	0.004 (2)	0.2500	0.4728 (12)	0.040 (5)*
H6B	0.160 (3)	0.2500	0.4356 (15)	0.059 (7)*
O8	0.47031 (15)	0.2500	0.66429 (9)	0.0559 (4)
C9	0.51525 (16)	0.2500	0.27711 (10)	0.0339 (4)
C10	0.42444 (17)	0.2500	0.35543 (9)	0.0383 (4)
O1	0.65463 (12)	0.2500	0.28894 (8)	0.0468 (4)
H1O	0.702 (3)	0.2500	0.2413 (19)	0.075 (8)*
O2	0.45898 (13)	0.2500	0.21184 (7)	0.0532 (4)
O3	0.28895 (12)	0.2500	0.34508 (7)	0.0530 (4)
O4	0.48880 (12)	0.2500	0.42032 (7)	0.0499 (4)
O1W	0.80123 (15)	0.2500	0.43969 (9)	0.0540 (4)
H1W	0.704 (4)	0.2500	0.4474 (17)	0.092 (10)*
H2W	0.803 (4)	0.2500	0.382 (3)	0.124 (12)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C2	0.0298 (8)	0.0416 (8)	0.0312 (8)	0.000	0.0007 (6)	0.000
C4	0.0336 (9)	0.0477 (9)	0.0353 (8)	0.000	−0.0035 (7)	0.000
C5	0.0371 (10)	0.0540 (9)	0.0295 (8)	0.000	−0.0029 (6)	0.000
C7	0.0315 (9)	0.0622 (11)	0.0368 (8)	0.000	0.0057 (7)	0.000
N1	0.0292 (7)	0.0530 (8)	0.0280 (7)	0.000	0.0013 (5)	0.000
N3	0.0278 (7)	0.0541 (9)	0.0310 (7)	0.000	0.0030 (6)	0.000
N6	0.0293 (7)	0.0705 (10)	0.0288 (7)	0.000	0.0016 (6)	0.000
O8	0.0347 (8)	0.0859 (10)	0.0471 (7)	0.000	−0.0083 (6)	0.000
C9	0.0215 (7)	0.0488 (9)	0.0316 (8)	0.000	−0.0013 (6)	0.000
C10	0.0224 (8)	0.0610 (10)	0.0314 (8)	0.000	0.0003 (6)	0.000
O1	0.0190 (6)	0.0893 (10)	0.0323 (7)	0.000	0.0008 (5)	0.000
O2	0.0252 (6)	0.1044 (11)	0.0300 (7)	0.000	−0.0024 (5)	0.000
O3	0.0201 (6)	0.1072 (12)	0.0318 (6)	0.000	0.0009 (5)	0.000
O4	0.0264 (6)	0.0940 (10)	0.0295 (6)	0.000	−0.0015 (5)	0.000
O1W	0.0311 (8)	0.0870 (11)	0.0438 (8)	0.000	−0.0076 (6)	0.000

Geometric parameters (Å, º)

C2—N6	1.303 (2)	C7—H7C	0.9600
C2—N1	1.321 (2)	N3—H3N	0.88 (3)
C2—N3	1.362 (2)	N6—H6A	0.90 (2)
C4—O8	1.204 (2)	N6—H6B	0.88 (3)
C4—N3	1.370 (2)	C9—O2	1.204 (2)
C4—C5	1.513 (2)	C9—O1	1.2936 (19)
C5—N1	1.455 (2)	C9—C10	1.548 (2)
C5—H5A	0.9700	C10—O4	1.231 (2)
C5—H5B	0.9700	C10—O3	1.255 (2)
C7—N1	1.448 (2)	O1—H1O	0.91 (3)
C7—H7A	0.9600	O1W—H1W	0.90 (3)
C7—H7B	0.9600	O1W—H2W	0.97 (4)
N6—C2—N1	126.28 (15)	C2—N1—C7	126.26 (14)
N6—C2—N3	123.09 (15)	C2—N1—C5	110.13 (13)
N1—C2—N3	110.63 (14)	C7—N1—C5	123.60 (14)
O8—C4—N3	126.47 (17)	C2—N3—C4	110.81 (14)
O8—C4—C5	127.59 (16)	C2—N3—H3N	123.8 (16)
N3—C4—C5	105.94 (13)	C4—N3—H3N	125.4 (16)
N1—C5—C4	102.49 (13)	C2—N6—H6A	121.8 (12)
N1—C5—H5A	111.3	C2—N6—H6B	116.2 (17)
C4—C5—H5A	111.3	H6A—N6—H6B	122 (2)
N1—C5—H5B	111.3	O2—C9—O1	124.16 (15)
C4—C5—H5B	111.3	O2—C9—C10	122.05 (14)
H5A—C5—H5B	109.2	O1—C9—C10	113.80 (13)
N1—C7—H7A	109.5	O4—C10—O3	126.54 (15)
N1—C7—H7B	109.5	O4—C10—C9	118.80 (14)
H7A—C7—H7B	109.5	O3—C10—C9	114.66 (13)
N1—C7—H7C	109.5	C9—O1—H1O	110.1 (18)
H7A—C7—H7C	109.5	H1W—O1W—H2W	99 (3)
H7B—C7—H7C	109.5
O8—C4—C5—N1	180.0	N6—C2—N3—C4	180.0
N3—C4—C5—N1	0.0	N1—C2—N3—C4	0.0
N6—C2—N1—C7	0.0	O8—C4—N3—C2	180.0
N3—C2—N1—C7	180.0	C5—C4—N3—C2	0.0
N6—C2—N1—C5	180.0	O2—C9—C10—O4	180.0
N3—C2—N1—C5	0.0	O1—C9—C10—O4	0.0
C4—C5—N1—C2	0.0	O2—C9—C10—O3	0.0
C4—C5—N1—C7	180.0	O1—C9—C10—O3	180.0

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H2W···O2^i	0.97 (4)	2.11 (4)	2.9094 (19)	138 (3)
O1W—H2W···O1	0.97 (4)	2.06 (4)	2.8484 (18)	138 (3)
O1W—H1W···O4	0.90 (3)	2.02 (3)	2.8840 (18)	159 (3)
O1—H1O···O3^i	0.91 (3)	1.64 (3)	2.5498 (16)	180 (3)
N6—H6B···O3	0.88 (3)	1.92 (3)	2.8012 (18)	179 (2)
N6—H6A···O1W^ii	0.90 (2)	1.94 (2)	2.825 (2)	169 (2)
N3—H3N···O4	0.88 (3)	1.92 (3)	2.7966 (18)	173 (2)

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