2-Amino-pyridinium trans-diaqua-bis-(oxalato-κ(2)O,O)chromate(III).

In the title hybrid salt, (C(5)H(7)N(2))[Cr(H(2)O)(2)(C(2)O(4))(2)], the Cr(III) ion is coordinated in a slightly distorted octa-hedral environment by four O atoms from two oxalate ligands in the equatorial plane and by two water O atoms in the axial sites. The 2-amino-pyridinium cation is disordered over two sets of sites in a 0.800 (7):0.200 (7) ratio. In the crystal, N-H⋯O and O-H⋯O hydrogen bonds connect the components into a three-dimensional network. The crystal studied was an inversion twin with components in a ratio 0.75 (2):0.25 (2).

Related literature

For general background to the coordination chemistry of oxalates, see: Martin et al. (2007 ▶). For the structural characterization of organic–inorganic salts containing the [Cr(H2O)2(C2O4)2]− anion, see: Bélombé et al. (2009 ▶); Nenwa et al. (2010 ▶); Chérif et al. (2011 ▶); Chérif, Abdelhak et al. (2012 ▶); Chérif, Zid et al. (2012 ▶).

Experimental

Crystal data

(C5H7N2)[Cr(H2O)2(C2O4)2]

M = 359.20

Monoclinic,

a = 6.8627 (14) Å

b = 19.434 (4) Å

c = 9.854 (2) Å

β = 99.90 (3)°

V = 1294.7 (5) Å3

Z = 4

Mo Kα radiation

μ = 0.94 mm−1

T = 100 K

0.23 × 0.15 × 0.10 mm

Data collection

Bruker SMART APEX CCD diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T min = 0.811, T max = 0.912

9645 measured reflections

3716 independent reflections

3391 reflections with I > 2σ(I)

R int = 0.035

Refinement

R[F 2 > 2σ(F 2)] = 0.039

wR(F 2) = 0.088

S = 1.04

3716 reflections

241 parameters

21 restraints

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.52 e Å−3

Δρmin = −0.30 e Å−3

Absolute structure: Flack (1983 ▶), 1793 Friedel pairs

Flack parameter: 0.25 (2)

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg, 2010 ▶); software used to prepare material for publication: WinGX Farrugia (1999 ▶).

Click here for additional data file.

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812040950/lh5534sup1.cif

Click here for additional data file.

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812040950/lh5534Isup2.hkl

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

(C5H7N2)[Cr(H2O)2(C2O4)2]	F(000) = 732
Mr = 359.20	Dx = 1.843 Mg m−3
Monoclinic, Ia	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: I -2ya	Cell parameters from 3716 reflections
a = 6.8627 (14) Å	θ = 2.4–30.7°
b = 19.434 (4) Å	µ = 0.94 mm−1
c = 9.854 (2) Å	T = 100 K
β = 99.90 (3)°	Prism, blue
V = 1294.7 (5) Å3	0.23 × 0.15 × 0.10 mm
Z = 4

Bruker SMART APEX CCD diffractometer	3716 independent reflections
Radiation source: fine-focus sealed tube	3391 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.035
φ and ω scans	θmax = 30.7°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Bruker, 2004)	h = −9→9
Tmin = 0.811, Tmax = 0.912	k = −27→26
9645 measured reflections	l = −13→13

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.039	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.088	w = 1/[σ2(Fo2) + (0.0372P)2 + 2.2822P] where P = (Fo2 + 2Fc2)/3
S = 1.04	(Δ/σ)max < 0.001
3716 reflections	Δρmax = 0.52 e Å−3
241 parameters	Δρmin = −0.30 e Å−3
21 restraints	Absolute structure: Flack (1983), 1793 Friedel pairs
Primary atom site location: structure-invariant direct methods	Flack parameter: 0.25 (2)

Experimental. A mixture of 2-aminopyridine (1 mmol, 100 mg) and oxalic acid (2 mmol, 260 mg) was dissolved in 30 ml of ethanol. An aqueous solution (20 ml) of CrCl3.6H2O (1 mmol, 266.5 mg) was added in successive small portions and stirred for 4 h continuously. The final blue-violet solution obtained was left at room temperature and crystals suitable for X-ray diffraction were obtained after a few days.

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s 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 > 2σ(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	Occ. (<1)
Cr1	0.19814 (16)	0.342519 (16)	0.68436 (13)	0.01109 (9)
C11	0.2455 (5)	0.48129 (16)	0.7396 (4)	0.0177 (7)
C12	0.1032 (5)	0.47555 (17)	0.6004 (3)	0.0195 (7)
O11	0.2936 (4)	0.53790 (12)	0.7885 (3)	0.0321 (6)
O12	0.0359 (4)	0.52679 (12)	0.5348 (3)	0.0282 (6)
O14	0.3031 (4)	0.42294 (13)	0.7934 (3)	0.0183 (5)
O13	0.0649 (4)	0.41336 (12)	0.5602 (3)	0.0180 (5)
C21	0.2715 (5)	0.20807 (17)	0.7621 (3)	0.0135 (6)
C22	0.1519 (5)	0.20649 (17)	0.6142 (4)	0.0145 (6)
O22	0.0979 (3)	0.26575 (12)	0.5654 (2)	0.0155 (5)
O21	0.3152 (3)	0.26885 (12)	0.8085 (2)	0.0134 (5)
O24	0.3136 (5)	0.15470 (11)	0.8242 (3)	0.0221 (7)
O23	0.1161 (5)	0.15033 (11)	0.5525 (3)	0.0201 (6)
OW1	−0.0319 (4)	0.33987 (10)	0.7854 (3)	0.0145 (5)
OW2	0.4360 (4)	0.34394 (10)	0.5912 (3)	0.0180 (5)
N1	0.2574 (5)	0.01644 (13)	0.7419 (4)	0.0213 (9)	0.800 (7)
H1A	0.3224	0.0271	0.8241	0.026*	0.800 (7)
H1B	0.2100	0.0492	0.6839	0.026*	0.800 (7)
N2	0.3078 (5)	−0.09776 (18)	0.7994 (3)	0.0141 (8)	0.800 (7)
H2	0.3733	−0.0840	0.8794	0.017*	0.800 (7)
C1	0.2309 (6)	−0.04927 (14)	0.7051 (4)	0.0134 (8)	0.800 (7)
C6	0.1323 (6)	−0.0728 (2)	0.5772 (4)	0.0150 (8)	0.800 (7)
H6	0.0779	−0.0409	0.5080	0.018*	0.800 (7)
C5	0.1146 (6)	−0.1417 (2)	0.5524 (4)	0.0180 (9)	0.800 (7)
H5	0.0494	−0.1574	0.4650	0.022*	0.800 (7)
C4	0.1916 (6)	−0.19022 (15)	0.6546 (4)	0.0161 (9)	0.800 (7)
H4	0.1756	−0.2382	0.6383	0.019*	0.800 (7)
C3	0.2877 (6)	−0.1664 (2)	0.7750 (4)	0.0152 (9)	0.800 (7)
H3	0.3429	−0.1980	0.8447	0.018*	0.800 (7)
N1A	0.161 (2)	0.0179 (4)	0.6157 (15)	0.031 (4)*	0.200 (7)
H1A1	0.2089	0.0479	0.6796	0.037*	0.200 (7)
H1A2	0.0995	0.0323	0.5348	0.037*	0.200 (7)
N2A	0.275 (2)	−0.0690 (6)	0.7682 (10)	0.021 (3)*	0.200 (7)
H2A1	0.3211	−0.0370	0.8285	0.025*	0.200 (7)
C1A	0.180 (2)	−0.0492 (4)	0.6414 (12)	0.011 (3)*	0.200 (7)
C6A	0.101 (2)	−0.1015 (6)	0.5499 (9)	0.007 (3)*	0.200 (7)
H6A	0.0292	−0.0900	0.4617	0.009*	0.200 (7)
C5A	0.129 (3)	−0.1687 (5)	0.5876 (14)	0.024 (5)*	0.200 (7)
H5A	0.0816	−0.2039	0.5234	0.028*	0.200 (7)
C4A	0.227 (2)	−0.1868 (5)	0.7210 (16)	0.020 (4)*	0.200 (7)
H4A	0.2377	−0.2335	0.7498	0.024*	0.200 (7)
C3A	0.303 (2)	−0.1361 (7)	0.8054 (11)	0.018 (4)*	0.200 (7)
H3A	0.3775	−0.1471	0.8930	0.022*	0.200 (7)
HW1A	0.016 (6)	0.3359 (17)	0.867 (2)	0.028*
HW1B	−0.099 (5)	0.3728 (13)	0.764 (4)	0.028*
HW2A	0.406 (6)	0.3418 (16)	0.5044 (19)	0.028*
HW2B	0.485 (5)	0.3815 (12)	0.600 (4)	0.028*

	U11	U22	U33	U12	U13	U23
Cr1	0.01435 (16)	0.00763 (14)	0.01064 (15)	0.0002 (2)	0.00028 (11)	0.0000 (2)
C11	0.0265 (17)	0.0098 (12)	0.0212 (14)	−0.0049 (11)	0.0168 (13)	−0.0041 (10)
C12	0.0276 (17)	0.0154 (15)	0.0190 (15)	0.0026 (12)	0.0138 (13)	0.0021 (12)
O11	0.0492 (16)	0.0181 (11)	0.0355 (14)	−0.0159 (10)	0.0257 (12)	−0.0135 (10)
O12	0.0499 (15)	0.0123 (10)	0.0273 (12)	0.0118 (10)	0.0205 (11)	0.0068 (9)
O14	0.0220 (11)	0.0174 (12)	0.0157 (10)	−0.0056 (9)	0.0036 (9)	−0.0046 (9)
O13	0.0271 (13)	0.0100 (11)	0.0181 (11)	0.0048 (8)	0.0071 (10)	0.0029 (8)
C21	0.0142 (13)	0.0143 (15)	0.0134 (13)	0.0026 (11)	0.0067 (10)	0.0014 (11)
C22	0.0155 (14)	0.0128 (14)	0.0167 (14)	−0.0029 (11)	0.0068 (11)	−0.0014 (11)
O22	0.0213 (12)	0.0118 (12)	0.0133 (10)	−0.0012 (8)	0.0029 (9)	−0.0013 (8)
O21	0.0150 (10)	0.0115 (11)	0.0126 (10)	0.0021 (8)	−0.0008 (8)	0.0015 (8)
O24	0.0332 (15)	0.0117 (12)	0.0247 (14)	0.0056 (9)	0.0147 (11)	0.0070 (8)
O23	0.0277 (13)	0.0115 (11)	0.0239 (13)	−0.0059 (9)	0.0121 (10)	−0.0076 (8)
OW1	0.0145 (12)	0.0110 (11)	0.0185 (12)	0.0034 (7)	0.0047 (10)	0.0008 (7)
OW2	0.0208 (14)	0.0133 (12)	0.0198 (12)	−0.0025 (7)	0.0031 (10)	−0.0011 (7)
N1	0.0254 (17)	0.0137 (14)	0.0246 (16)	−0.0009 (11)	0.0033 (13)	−0.0023 (11)
N2	0.0150 (15)	0.0179 (19)	0.0084 (13)	0.0007 (12)	−0.0013 (11)	0.0031 (12)
C1	0.016 (2)	0.0140 (14)	0.011 (2)	0.0005 (12)	0.0032 (15)	0.0028 (12)
C6	0.0124 (17)	0.020 (2)	0.0107 (16)	0.0040 (14)	−0.0026 (13)	−0.0003 (15)
C5	0.0127 (17)	0.024 (2)	0.0158 (18)	0.0029 (16)	−0.0016 (13)	−0.0073 (16)
C4	0.0159 (18)	0.0116 (14)	0.020 (2)	−0.0013 (14)	0.0019 (19)	−0.0036 (12)
C3	0.0151 (18)	0.0116 (17)	0.0193 (19)	−0.0014 (14)	0.0039 (14)	−0.0011 (14)

Cr1—O22	1.949 (2)	N2—C1	1.364 (4)
Cr1—O13	1.960 (2)	N2—H2	0.8800
Cr1—O14	1.962 (2)	C1—C6	1.402 (5)
Cr1—O21	1.963 (2)	C6—C5	1.363 (5)
Cr1—OW2	2.006 (3)	C6—H6	0.9500
Cr1—OW1	2.007 (3)	C5—C4	1.414 (5)
C11—O11	1.223 (4)	C5—H5	0.9500
C11—O14	1.285 (4)	C4—C3	1.337 (5)
C11—C12	1.545 (4)	C4—H4	0.9500
C12—O12	1.233 (4)	C3—H3	0.9500
C12—O13	1.285 (4)	N1A—C1A	1.331 (4)
C21—O24	1.214 (4)	N1A—H1A1	0.8800
C21—O21	1.283 (4)	N1A—H1A2	0.8800
C21—C22	1.545 (3)	N2A—C3A	1.359 (5)
C22—O23	1.253 (4)	N2A—C1A	1.363 (5)
C22—O22	1.278 (4)	N2A—H2A1	0.8800
OW1—HW1A	0.816 (18)	C1A—C6A	1.402 (5)
OW1—HW1B	0.796 (18)	C6A—C5A	1.363 (5)
OW2—HW2A	0.846 (18)	C6A—H6A	0.9500
OW2—HW2B	0.803 (18)	C5A—C4A	1.414 (6)
N1—C1	1.331 (3)	C5A—H5A	0.9500
N1—H1A	0.8800	C4A—C3A	1.337 (6)
N1—H1B	0.8800	C4A—H4A	0.9500
N2—C3	1.358 (4)	C3A—H3A	0.9500
O22—Cr1—O13	94.80 (11)	C3—N2—C1	122.9 (3)
O22—Cr1—O14	176.23 (12)	C3—N2—H2	118.6
O13—Cr1—O14	82.55 (9)	C1—N2—H2	118.6
O22—Cr1—O21	83.15 (7)	N1—C1—N2	117.3 (4)
O13—Cr1—O21	176.38 (11)	N1—C1—C6	125.5 (4)
O14—Cr1—O21	99.63 (11)	N2—C1—C6	117.2 (3)
O22—Cr1—OW2	88.05 (9)	C5—C6—C1	119.8 (3)
O13—Cr1—OW2	91.94 (10)	C5—C6—H6	120.1
O14—Cr1—OW2	89.36 (10)	C1—C6—H6	120.1
O21—Cr1—OW2	90.98 (10)	C6—C5—C4	121.1 (3)
O22—Cr1—OW1	93.02 (9)	C6—C5—H5	119.5
O13—Cr1—OW1	90.31 (10)	C4—C5—H5	119.5
O14—Cr1—OW1	89.68 (10)	C3—C4—C5	117.9 (3)
O21—Cr1—OW1	86.82 (9)	C3—C4—H4	121.0
OW2—Cr1—OW1	177.42 (14)	C5—C4—H4	121.0
O11—C11—O14	126.0 (4)	C4—C3—N2	121.1 (3)
O11—C11—C12	120.1 (3)	C4—C3—H3	119.4
O14—C11—C12	113.9 (3)	N2—C3—H3	119.4
O12—C12—O13	124.1 (3)	C1A—N1A—H1A1	120.0
O12—C12—C11	122.0 (3)	C1A—N1A—H1A2	120.0
O13—C12—C11	114.0 (3)	H1A1—N1A—H1A2	120.0
C11—O14—Cr1	114.8 (2)	C3A—N2A—C1A	122.7 (4)
C12—O13—Cr1	114.8 (2)	C3A—N2A—H2A1	118.6
O24—C21—O21	125.9 (3)	C1A—N2A—H2A1	118.6
O24—C21—C22	120.0 (4)	N1A—C1A—N2A	117.8 (5)
O21—C21—C22	114.1 (3)	N1A—C1A—C6A	125.0 (5)
O23—C22—O22	125.6 (4)	N2A—C1A—C6A	117.1 (3)
O23—C22—C21	120.2 (4)	C5A—C6A—C1A	120.0 (4)
O22—C22—C21	114.2 (3)	C5A—C6A—H6A	120.0
C22—O22—Cr1	114.4 (2)	C1A—C6A—H6A	120.0
C21—O21—Cr1	113.8 (2)	C6A—C5A—C4A	120.9 (4)
Cr1—OW1—HW1A	106 (3)	C6A—C5A—H5A	119.6
Cr1—OW1—HW1B	108 (3)	C4A—C5A—H5A	119.6
HW1A—OW1—HW1B	117 (3)	C3A—C4A—C5A	117.8 (4)
Cr1—OW2—HW2A	113 (3)	C3A—C4A—H4A	121.1
Cr1—OW2—HW2B	109 (3)	C5A—C4A—H4A	121.1
HW2A—OW2—HW2B	100 (3)	C4A—C3A—N2A	121.3 (4)
C1—N1—H1A	120.0	C4A—C3A—H3A	119.4
C1—N1—H1B	120.0	N2A—C3A—H3A	119.4
H1A—N1—H1B	120.0

D—H···A	D—H	H···A	D···A	D—H···A
OW1—HW1A···O23i	0.82 (2)	1.86 (2)	2.660 (4)	166 (3)
OW1—HW1B···O11ii	0.80 (2)	1.92 (2)	2.663 (3)	156 (4)
OW2—HW2A···O24iii	0.85 (2)	1.78 (2)	2.621 (4)	172 (4)
OW2—HW2B···O12iv	0.80 (2)	1.95 (2)	2.687 (3)	153 (4)
N1—H1A···O12v	0.88	2.33	3.183 (5)	164
N1—H1B···O23	0.88	2.38	3.251 (4)	171
N2—H2···O13v	0.88	2.02	2.865 (3)	159

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
OW1—HW1A⋯O23i	0.82 (2)	1.86 (2)	2.660 (4)	166 (3)
OW1—HW1B⋯O11ii	0.80 (2)	1.92 (2)	2.663 (3)	156 (4)
OW2—HW2A⋯O24iii	0.85 (2)	1.78 (2)	2.621 (4)	172 (4)
OW2—HW2B⋯O12iv	0.80 (2)	1.95 (2)	2.687 (3)	153 (4)
N1—H1A⋯O12v	0.88	2.33	3.183 (5)	164
N1—H1B⋯O23	0.88	2.38	3.251 (4)	171
N2—H2⋯O13v	0.88	2.02	2.865 (3)	159

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