4-Amino-pyridinium trans-diaqua-dioxalatochromate(III) monohydrate.

In the non-centrosymmetric structure of the title compound, (C(5)H(7)N(2))[Cr(C(2)O(4))(2)(H(2)O)(2)]·H(2)O, the Cr(III) ion has a slightly distorted octa-hedral coordination environment defined by two chelating oxalato ligands in equatorial positions and two water mol-ecules in axial positions. An extensive three-dimensional network of hydrogen bonds involving all the water mol-ecules, the 4-amino-pyridinium cation and some of the oxalate O atoms contributes to the stabilization of the structure. π-π inter-actions between adjacent pyridine rings provide additional stability of the crystal packing, with a closest distance between pyridine mean planes of 3.613 (1) Å.

Related literature

For the structural characterization of salts containing the [Cr(C2O4)2(H2O)2]− anion with various counter-cations, see: Bélombé et al. (2009 ▶); Nenwa et al. (2010 ▶). For oxalate coord­ination modes, see: Tang et al. (2002 ▶); Martak et al. (2009 ▶); Hernández-Molina et al. (2001 ▶); Zhao et al. (2004 ▶). For C—O distances in oxalate anions, see: Marinescu et al. (2000 ▶). For geometric parameters of the 4-amino­pyridinium cation, see: Fun et al. (2008 ▶, 2009 ▶, 2010 ▶); Jebas et al. (2009 ▶); Quah et al. (2008 ▶); Ramesh et al. (2010 ▶); Rotondo et al. (2009 ▶); Pan et al. (2008 ▶). For discussion of hydrogen bonding, see: Blessing (1986 ▶); Brown (1976 ▶).

Experimental

Crystal data

(C5H7N2)[Cr(C2O4)2(H2O)2]·H2O

M = 377.21

Orthorhombic,

a = 21.102 (4) Å

b = 9.487 (3) Å

c = 7.226 (2) Å

V = 1446.7 (7) Å3

Z = 4

Mo Kα radiation

μ = 0.85 mm−1

T = 298 K

0.54 × 0.18 × 0.12 mm

Data collection

Enraf–Nonius CAD-4 diffractometer

Absorption correction: ψ scan (North et al., 1968 ▶) T min = 0.832, T max = 0.903

3729 measured reflections

3150 independent reflections

2857 reflections with I > 2σ(I)

R int = 0.017

2 standard reflections every 120 min intensity decay: 2.9%

Refinement

R[F 2 > 2σ(F 2)] = 0.025

wR(F 2) = 0.066

S = 1.04

3150 reflections

261 parameters

1 restraint

All H-atom parameters refined

Δρmax = 0.30 e Å−3

Δρmin = −0.31 e Å−3

Absolute structure: Flack (1983 ▶), 1447 Friedel pairs

Flack parameter: 0.000 (16)

Data collection: CAD-4 EXPRESS (Duisenberg, 1992 ▶; Macíček & Yordanov, 1992 ▶); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg, 1998 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811044837/wm2545sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811044837/wm2545Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

(C5H7N2)[Cr(C2O4)2(H2O)2]·H2O	F(000) = 772
Mr = 377.21	Dx = 1.732 Mg m−3
Orthorhombic, Pna21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2n	Cell parameters from 25 reflections
a = 21.102 (4) Å	θ = 10–15°
b = 9.487 (3) Å	µ = 0.85 mm−1
c = 7.226 (2) Å	T = 298 K
V = 1446.7 (7) Å3	Prism, violet
Z = 4	0.54 × 0.18 × 0.12 mm

Enraf–Nonius CAD-4 diffractometer	2857 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.017
graphite	θmax = 27.0°, θmin = 2.4°
ω/2θ scans	h = −26→1
Absorption correction: ψ scan (North et al., 1968)	k = −1→12
Tmin = 0.832, Tmax = 0.903	l = −9→9
3729 measured reflections	2 standard reflections every 120 min
3150 independent reflections	intensity decay: 2.9%

Refinement on F2	Hydrogen site location: difference Fourier map
Least-squares matrix: full	All H-atom parameters refined
R[F2 > 2σ(F2)] = 0.025	w = 1/[σ2(Fo2) + (0.0364P)2 + 0.1566P] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.066	(Δ/σ)max < 0.001
S = 1.04	Δρmax = 0.30 e Å−3
3150 reflections	Δρmin = −0.31 e Å−3
261 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
1 restraint	Extinction coefficient: 0.0022 (7)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack (1983), 1447 Friedel pairs
Secondary atom site location: difference Fourier map	Flack parameter: 0.000 (16)

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 > 2sigma(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.

	x	y	z	Uiso*/Ueq
Cr1	−0.196274 (13)	0.09444 (3)	−0.00116 (5)	0.01985 (9)
O9	−0.19814 (7)	0.26620 (15)	0.5002 (3)	0.0295 (3)
O3	−0.27673 (7)	0.09078 (16)	0.1400 (2)	0.0262 (3)
O1	−0.11408 (7)	0.10787 (17)	−0.1273 (2)	0.0264 (3)
OW1	−0.17053 (9)	−0.08746 (18)	0.1118 (2)	0.0283 (3)
O4	−0.16685 (7)	0.19731 (16)	0.2188 (2)	0.0248 (3)
OW2	−0.22205 (8)	0.27650 (18)	−0.1212 (2)	0.0295 (3)
O7	−0.17687 (8)	−0.09782 (17)	−0.4830 (3)	0.0340 (4)
O2	−0.22078 (7)	−0.00965 (16)	−0.2262 (2)	0.0243 (3)
O10	−0.31987 (7)	0.17303 (18)	0.4006 (2)	0.0337 (4)
O8	−0.06261 (8)	0.0179 (2)	−0.3698 (3)	0.0430 (5)
C3	−0.27494 (10)	0.1550 (2)	0.2972 (3)	0.0228 (4)
C1	−0.17435 (10)	−0.0316 (2)	−0.3382 (3)	0.0222 (4)
C4	−0.20797 (10)	0.2123 (2)	0.3479 (3)	0.0218 (4)
C2	−0.11043 (10)	0.0354 (2)	−0.2779 (3)	0.0252 (4)
C6	−0.42595 (16)	0.1102 (4)	0.0242 (6)	0.0625 (10)
C8	−0.51027 (14)	−0.1061 (3)	0.0042 (7)	0.0524 (7)
N1	−0.40576 (12)	−0.0224 (3)	0.0161 (6)	0.0657 (8)
N2	−0.59497 (12)	0.0580 (3)	0.0089 (8)	0.0750 (10)
C9	−0.53327 (11)	0.0317 (3)	0.0117 (5)	0.0413 (5)
C7	−0.44661 (16)	−0.1296 (4)	0.0020 (8)	0.0726 (10)
OW3	−0.06036 (9)	0.9143 (3)	0.2640 (3)	0.0449 (5)
C5	−0.48794 (15)	0.1402 (3)	0.0211 (7)	0.0597 (8)
H8	−0.5357 (18)	−0.181 (4)	0.003 (6)	0.079 (11)*
H2	−0.6222 (18)	−0.014 (4)	−0.026 (6)	0.076 (12)*
H1	−0.359 (2)	−0.038 (5)	0.028 (7)	0.098 (14)*
HW31	−0.0613 (16)	0.955 (4)	0.358 (6)	0.047 (10)*
HW21	−0.2581 (18)	0.323 (4)	−0.100 (5)	0.068 (11)*
HW11	−0.1303 (19)	−0.085 (4)	0.155 (5)	0.058 (10)*
H6	−0.3942 (19)	0.183 (4)	0.031 (6)	0.079 (12)*
HW32	−0.022 (2)	0.948 (4)	0.220 (6)	0.077 (12)*
H5	−0.5032 (19)	0.233 (4)	0.043 (5)	0.077 (12)*
H3	−0.606 (2)	0.147 (5)	0.010 (7)	0.094 (13)*
H7	−0.428 (2)	−0.226 (5)	0.001 (8)	0.110 (15)*
HW12	−0.180 (2)	−0.146 (5)	0.045 (7)	0.094 (16)*
HW22	−0.2234 (18)	0.269 (4)	−0.223 (6)	0.070 (13)*

	U11	U22	U33	U12	U13	U23
Cr1	0.01992 (14)	0.02436 (15)	0.01528 (14)	−0.00098 (11)	0.00098 (14)	−0.00316 (16)
O9	0.0352 (7)	0.0347 (7)	0.0187 (6)	−0.0031 (6)	0.0000 (7)	−0.0086 (10)
O3	0.0232 (7)	0.0314 (8)	0.0241 (8)	−0.0029 (6)	0.0011 (6)	−0.0063 (7)
O1	0.0233 (7)	0.0359 (9)	0.0200 (7)	−0.0051 (6)	0.0011 (6)	−0.0079 (6)
OW1	0.0317 (9)	0.0281 (8)	0.0253 (8)	0.0011 (7)	−0.0057 (7)	−0.0039 (6)
O4	0.0227 (7)	0.0314 (7)	0.0203 (7)	−0.0045 (6)	0.0026 (5)	−0.0064 (6)
OW2	0.0336 (8)	0.0330 (9)	0.0218 (8)	0.0075 (7)	0.0028 (7)	0.0014 (7)
O7	0.0371 (8)	0.0425 (8)	0.0225 (9)	−0.0094 (7)	0.0013 (9)	−0.0108 (8)
O2	0.0229 (7)	0.0299 (8)	0.0202 (6)	−0.0049 (6)	−0.0002 (6)	−0.0026 (6)
O10	0.0303 (8)	0.0364 (9)	0.0344 (9)	−0.0051 (7)	0.0134 (7)	−0.0095 (7)
O8	0.0265 (9)	0.0681 (13)	0.0345 (9)	−0.0075 (9)	0.0089 (7)	−0.0186 (9)
C3	0.0259 (10)	0.0191 (10)	0.0234 (10)	−0.0012 (8)	0.0037 (8)	−0.0008 (8)
C1	0.0266 (10)	0.0228 (9)	0.0172 (9)	−0.0029 (8)	−0.0010 (8)	−0.0013 (8)
C4	0.0267 (10)	0.0201 (9)	0.0184 (9)	0.0004 (8)	−0.0002 (8)	−0.0006 (8)
C2	0.0250 (10)	0.0308 (11)	0.0198 (10)	−0.0021 (9)	0.0015 (8)	−0.0043 (8)
C6	0.0454 (16)	0.075 (2)	0.067 (3)	−0.0191 (16)	−0.0159 (18)	0.013 (2)
C8	0.0456 (14)	0.0354 (13)	0.0761 (19)	0.0017 (11)	−0.001 (2)	0.0092 (18)
N1	0.0334 (12)	0.086 (2)	0.077 (2)	0.0050 (13)	−0.0007 (15)	0.025 (2)
N2	0.0337 (11)	0.0442 (14)	0.147 (3)	0.0059 (11)	−0.019 (2)	−0.022 (2)
C9	0.0334 (11)	0.0362 (12)	0.0542 (15)	0.0001 (9)	−0.0069 (14)	−0.0041 (15)
C7	0.0562 (18)	0.0569 (18)	0.105 (3)	0.0222 (15)	0.009 (3)	0.018 (3)
OW3	0.0304 (10)	0.0753 (15)	0.0290 (9)	0.0014 (10)	−0.0009 (8)	−0.0084 (10)
C5	0.0484 (15)	0.0403 (14)	0.090 (3)	−0.0076 (12)	−0.0156 (19)	−0.002 (2)

Cr1—O1	1.9636 (15)	C3—C4	1.558 (3)
Cr1—O4	1.9658 (15)	C1—C2	1.553 (3)
Cr1—O2	1.9715 (16)	C6—N1	1.330 (5)
Cr1—O3	1.9810 (16)	C6—C5	1.339 (5)
Cr1—OW1	1.9847 (17)	C6—H6	0.96 (4)
Cr1—OW2	2.0079 (18)	C8—C7	1.362 (4)
O9—C4	1.231 (3)	C8—C9	1.396 (4)
O3—C3	1.289 (3)	C8—H8	0.89 (4)
O1—C2	1.290 (3)	N1—C7	1.337 (5)
OW1—HW11	0.91 (4)	N1—H1	1.00 (5)
OW1—HW12	0.77 (5)	N2—C9	1.326 (3)
O4—C4	1.282 (2)	N2—H2	0.92 (4)
OW2—HW21	0.89 (4)	N2—H3	0.88 (4)
OW2—HW22	0.74 (4)	C9—C5	1.407 (4)
O7—C1	1.222 (3)	C7—H7	1.00 (5)
O2—C1	1.287 (3)	OW3—HW31	0.78 (4)
O10—C3	1.219 (3)	OW3—HW32	0.93 (4)
O8—C2	1.219 (3)	C5—H5	0.95 (4)
O1—Cr1—O4	93.67 (6)	O2—C1—C2	114.75 (17)
O1—Cr1—O2	83.18 (6)	O9—C4—O4	125.64 (19)
O4—Cr1—O2	176.78 (6)	O9—C4—C3	120.54 (18)
O1—Cr1—O3	175.74 (7)	O4—C4—C3	113.82 (16)
O4—Cr1—O3	82.13 (6)	O8—C2—O1	125.6 (2)
O2—Cr1—O3	101.02 (6)	O8—C2—C1	120.68 (19)
O1—Cr1—OW1	90.32 (7)	O1—C2—C1	113.75 (18)
O4—Cr1—OW1	90.73 (7)	N1—C6—C5	120.9 (3)
O2—Cr1—OW1	88.59 (7)	N1—C6—H6	117 (2)
O3—Cr1—OW1	90.43 (7)	C5—C6—H6	122 (2)
O1—Cr1—OW2	89.02 (7)	C7—C8—C9	119.8 (3)
O4—Cr1—OW2	90.45 (7)	C7—C8—H8	118 (2)
O2—Cr1—OW2	90.20 (8)	C9—C8—H8	123 (2)
O3—Cr1—OW2	90.31 (7)	C6—N1—C7	121.1 (3)
OW1—Cr1—OW2	178.68 (8)	C6—N1—H1	117 (3)
C3—O3—Cr1	114.84 (14)	C7—N1—H1	122 (3)
C2—O1—Cr1	114.20 (13)	C9—N2—H2	118 (2)
Cr1—OW1—HW11	112 (2)	C9—N2—H3	117 (3)
Cr1—OW1—HW12	107 (4)	H2—N2—H3	123 (4)
HW11—OW1—HW12	119 (4)	N2—C9—C8	121.2 (2)
C4—O4—Cr1	115.46 (13)	N2—C9—C5	122.0 (3)
Cr1—OW2—HW21	126 (2)	C8—C9—C5	116.8 (3)
Cr1—OW2—HW22	111 (3)	N1—C7—C8	120.7 (3)
HW21—OW2—HW22	100 (4)	N1—C7—H7	116 (3)
C1—O2—Cr1	113.56 (13)	C8—C7—H7	123 (3)
O10—C3—O3	125.7 (2)	HW31—OW3—HW32	98 (4)
O10—C3—C4	120.81 (18)	C6—C5—C9	120.6 (3)
O3—C3—C4	113.51 (17)	C6—C5—H5	122 (2)
O7—C1—O2	126.0 (2)	C9—C5—H5	117 (2)
O7—C1—C2	119.22 (19)

D—H···A	D—H	H···A	D···A	D—H···A
OW3—HW31···O8i	0.78 (4)	2.06 (4)	2.823 (3)	167 (4)
OW3—HW32···O8ii	0.93 (4)	1.93 (4)	2.843 (3)	169 (4)
OW2—HW21···O7iii	0.89 (4)	1.78 (4)	2.640 (3)	161 (3)
OW2—HW22···O9iv	0.74 (4)	2.07 (4)	2.784 (3)	162 (4)
OW1—HW11···OW3v	0.90 (4)	1.67 (4)	2.572 (3)	172 (4)
OW1—HW12···O10vi	0.76 (5)	2.01 (5)	2.745 (3)	162 (5)
N2—H2···O10vii	0.93 (4)	2.01 (4)	2.940 (4)	179 (4)
N1—H1···O3	1.00 (4)	2.27 (4)	3.061 (3)	135 (4)
N1—H1···O9vi	1.00 (4)	2.22 (4)	2.974 (3)	131 (4)

Table 1

Selected bond lengths (Å)

Cr1—O1	1.9636 (15)
Cr1—O4	1.9658 (15)
Cr1—O2	1.9715 (16)
Cr1—O3	1.9810 (16)
Cr1—OW1	1.9847 (17)
Cr1—OW2	2.0079 (18)

Table 2

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
OW3—HW31⋯O8i	0.78 (4)	2.06 (4)	2.823 (3)	167 (4)
OW3—HW32⋯O8ii	0.93 (4)	1.93 (4)	2.843 (3)	169 (4)
OW2—HW21⋯O7iii	0.89 (4)	1.78 (4)	2.640 (3)	161 (3)
OW2—HW22⋯O9iv	0.74 (4)	2.07 (4)	2.784 (3)	162 (4)
OW1—HW11⋯OW3v	0.90 (4)	1.67 (4)	2.572 (3)	172 (4)
OW1—HW12⋯O10vi	0.76 (5)	2.01 (5)	2.745 (3)	162 (5)
N2—H2⋯O10vii	0.93 (4)	2.01 (4)	2.940 (4)	179 (4)
N1—H1⋯O3	1.00 (4)	2.27 (4)	3.061 (3)	135 (4)
N1—H1⋯O9vi	1.00 (4)	2.22 (4)	2.974 (3)	131 (4)

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) ; (vi) ; (vii) .