Creatininium phosphite

The title salt, C₄H₈N₃O⁺·H₂PO₃⁻, contains a creatininium cation (2-amino-1-methyl-4-oxo-4,5-di­hydro-1H-imidazol-3-ium) and a phosphite anion. The crystal packing shows layers of hydrogen-bonded ions lying parallel to the (-114) and (11-4) planes.

Computing details

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

2-Amino-1-methyl-4-oxo-4,5-dihydro-1H-imidazol-3-ium phosphite

Crystal data

C4H8N3O^+·H2O3P^−	F(000) = 408
Mr = 195.12	Dx = 1.493 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2806 reflections
a = 8.8083 (11) Å	θ = 2.7–31.3°
b = 6.6316 (9) Å	µ = 0.30 mm^−1
c = 15.068 (2) Å	T = 296 K
β = 99.539 (4)°	Block, colourless
V = 868.0 (2) Å^3	0.20 × 0.20 × 0.15 mm
Z = 4

Data collection

Bruker APEXII CCD diffractometer	2806 independent reflections
Radiation source: fine-focus sealed tube	1735 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.058
Detector resolution: 0 pixels mm^-1	θmax = 31.3°, θmin = 2.7°
ω and φ scans	h = −12→12
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	k = −9→9
Tmin = 0.942, Tmax = 0.956	l = −21→22
17033 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)] = 0.056	H-atom parameters constrained
wR(F^2) = 0.152	w = 1/[σ^2(Fo^2) + (0.0518P)^2 + 0.7395P] where P = (Fo^2 + 2Fc^2)/3
S = 1.10	(Δ/σ)max = 0.001
2806 reflections	Δρmax = 0.41 e Å^−3
112 parameters	Δρmin = −0.48 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.016 (3)

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

	x	y	z	Uiso*/Ueq
C1	0.9486 (3)	0.6568 (4)	0.82130 (17)	0.0371 (6)
C2	0.7886 (3)	0.5893 (4)	0.78225 (18)	0.0411 (6)
H2A	0.7124	0.6864	0.7945	0.049*
H2B	0.7781	0.5690	0.7178	0.049*
C3	0.9043 (3)	0.3583 (4)	0.88290 (15)	0.0288 (5)
C4	0.6448 (4)	0.2661 (5)	0.8068 (2)	0.0604 (9)
H4A	0.6381	0.2209	0.7458	0.091*
H4B	0.5519	0.3359	0.8135	0.091*
H4C	0.6582	0.1519	0.8465	0.091*
N1	1.0075 (2)	0.5102 (3)	0.88175 (14)	0.0311 (4)
H1	1.0973	0.5141	0.9144	0.037*
N2	0.7741 (2)	0.4002 (3)	0.82874 (14)	0.0369 (5)
N3	0.9339 (2)	0.1983 (3)	0.93186 (15)	0.0394 (5)
H3A	0.8651	0.1060	0.9311	0.047*
H3B	1.0225	0.1842	0.9652	0.047*
O1	1.0143 (3)	0.8075 (3)	0.80485 (15)	0.0575 (6)
O2	1.3127 (2)	0.4455 (3)	0.95142 (14)	0.0501 (6)
O3	1.2272 (2)	0.1521 (3)	1.03801 (13)	0.0435 (5)
O4	1.4909 (2)	0.2863 (3)	1.08076 (14)	0.0506 (6)
H4	1.5505	0.3698	1.0658	0.076*
P1	1.35438 (7)	0.25366 (10)	1.00218 (5)	0.0336 (2)
H1A	1.3903	0.1593	0.9601	0.040*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0422 (14)	0.0362 (14)	0.0346 (13)	0.0032 (11)	0.0109 (11)	0.0059 (11)
C2	0.0395 (14)	0.0473 (15)	0.0351 (13)	0.0085 (12)	0.0024 (11)	0.0080 (12)
C3	0.0269 (11)	0.0309 (12)	0.0283 (11)	−0.0017 (9)	0.0037 (9)	−0.0001 (9)
C4	0.0389 (16)	0.074 (2)	0.061 (2)	−0.0176 (16)	−0.0118 (14)	0.0016 (17)
N1	0.0279 (10)	0.0288 (10)	0.0354 (10)	−0.0039 (8)	0.0018 (8)	0.0028 (8)
N2	0.0279 (10)	0.0444 (12)	0.0366 (11)	−0.0025 (9)	−0.0001 (8)	0.0037 (9)
N3	0.0307 (11)	0.0323 (11)	0.0511 (13)	−0.0109 (9)	−0.0055 (10)	0.0085 (10)
O1	0.0677 (15)	0.0442 (12)	0.0624 (14)	−0.0077 (10)	0.0158 (11)	0.0210 (10)
O2	0.0263 (9)	0.0522 (12)	0.0668 (14)	−0.0108 (8)	−0.0071 (9)	0.0278 (10)
O3	0.0318 (10)	0.0419 (11)	0.0554 (11)	−0.0127 (8)	0.0033 (8)	0.0104 (9)
O4	0.0342 (10)	0.0585 (14)	0.0536 (12)	−0.0164 (9)	−0.0090 (9)	0.0230 (10)
P1	0.0249 (3)	0.0355 (3)	0.0398 (4)	−0.0038 (3)	0.0034 (2)	0.0050 (3)

Geometric parameters (Å, º)

C1—O1	1.201 (3)	C4—H4B	0.9600
C1—N1	1.374 (3)	C4—H4C	0.9600
C1—C2	1.502 (4)	N1—H1	0.8600
C2—N2	1.452 (4)	N3—H3A	0.8600
C2—H2A	0.9700	N3—H3B	0.8600
C2—H2B	0.9700	O2—P1	1.4983 (19)
C3—N3	1.294 (3)	O3—P1	1.4833 (18)
C3—N2	1.322 (3)	O4—P1	1.5566 (19)
C3—N1	1.359 (3)	O4—H4	0.8200
C4—N2	1.440 (4)	P1—H1A	0.9800
C4—H4A	0.9600
O1—C1—N1	125.7 (3)	H4B—C4—H4C	109.5
O1—C1—C2	128.3 (2)	C3—N1—C1	110.7 (2)
N1—C1—C2	106.0 (2)	C3—N1—H1	124.7
N2—C2—C1	102.7 (2)	C1—N1—H1	124.7
N2—C2—H2A	111.2	C3—N2—C4	125.7 (2)
C1—C2—H2A	111.2	C3—N2—C2	110.0 (2)
N2—C2—H2B	111.2	C4—N2—C2	123.5 (2)
C1—C2—H2B	111.2	C3—N3—H3A	120.0
H2A—C2—H2B	109.1	C3—N3—H3B	120.0
N3—C3—N2	126.6 (2)	H3A—N3—H3B	120.0
N3—C3—N1	122.9 (2)	P1—O4—H4	109.5
N2—C3—N1	110.5 (2)	O3—P1—O2	115.80 (11)
N2—C4—H4A	109.5	O3—P1—O4	108.73 (11)
N2—C4—H4B	109.5	O2—P1—O4	111.31 (11)
H4A—C4—H4B	109.5	O3—P1—H1A	106.8
N2—C4—H4C	109.5	O2—P1—H1A	106.8
H4A—C4—H4C	109.5	O4—P1—H1A	106.8
O1—C1—C2—N2	−179.2 (3)	N3—C3—N2—C4	−6.6 (4)
N1—C1—C2—N2	0.4 (3)	N1—C3—N2—C4	173.9 (3)
N3—C3—N1—C1	177.4 (2)	N3—C3—N2—C2	−177.2 (2)
N2—C3—N1—C1	−3.1 (3)	N1—C3—N2—C2	3.4 (3)
O1—C1—N1—C3	−178.9 (3)	C1—C2—N2—C3	−2.3 (3)
C2—C1—N1—C3	1.5 (3)	C1—C2—N2—C4	−173.1 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2B···O1^i	0.97	2.58	2.997 (4)	106
C4—H4C···N3	0.96	2.57	2.941 (4)	103
C4—H4A···O4^ii	0.96	2.61	3.470 (3)	150
N1—H1···O2	0.86	1.94	2.754 (2)	157
N3—H3A···O3^iii	0.86	1.98	2.800 (2)	158
N3—H3B···O3	0.86	1.96	2.821 (2)	178
O4—H4···O2^iv	0.82	1.77	2.585 (2)	170

Symmetry codes: (i) −x+2, y−1/2, −z+3/2; (ii) x−1, −y+1/2, z−1/2; (iii) −x+2, −y, −z+2; (iv) −x+3, −y+1, −z+2.