4-(Dimethyl-amino)-pyridinium trans-diaqua-bis-[oxalato(2-)-κO,O]chromate(III).

In the title salt, (C(7)H(11)N(2))[Cr(C(2)O(4))(2)(H(2)O)(2)], the asymmetric unit contains one half-cation and one half-anion. The Cr atom, the C and N atoms involved in C- N(exocyclic) bonding and the N and H atoms of N-H groups lie on twofold rotation axis. The Cr(III) atom of the complex anion is six-coordinated in a distorted (4 + 2) octa-hedral geometry with four equatorial O atoms of two nearly coplanar oxalate and two quasi-axial aqua O atoms. In the crystal, the protonated N atoms of the pyridine rings are hydrogen bonded to the carbonyl O atoms of the anions, forming chains along [010]. These chains are connected by lateral O-H⋯O hydrogen bonds, stabilizing the structure.

Related literature

For general background to the coordination chemistry of oxalate, see: Martin et al. (2007 ▶). For related structures, see: Bélombé et al. (2009 ▶); Ghouili et al. (2010 ▶).

Experimental

Crystal data

(C7H11N2)[n class="Chemical">Cr(C2O4)2(H2O)2]

M = 387.25

Monoclinic,

a = 11.524 (4) Å

b = 20.372 (8) Å

c = 7.355 (2) Å

β = 120.626 (6)°

V = 1485.9 (9) Å3

Z = 4

Mo Kα radiation

μ = 0.83 mm−1

T = 293 K

0.20 × 0.20 × 0.10 mm

Data collection

Bruker APEX CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T min = 0.895, T max = 0.910

10203 measured reflections

1857 independent reflections

1739 reflections with I > 2σ(I)

R int = 0.046

Refinement

R[F 2 > 2σ(F 2)] = 0.033

wR(F 2) = 0.089

S = 1.16

1857 reflections

127 parameters

2 restraints

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.37 e Å−3

Δρmin = −0.38 e Å−3

Data collection: SMART (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 ▶).

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810040353/bx2312sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810040353/bx2312Isup2.hkl

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

(C7H11N2)[Cr(C2O4)2(H2O)2]	F(000) = 796
Mr = 387.25	Dx = 1.731 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 1857 reflections
a = 11.524 (4) Å	θ = 2.0–28.3°
b = 20.372 (8) Å	µ = 0.83 mm−1
c = 7.355 (2) Å	T = 293 K
β = 120.626 (6)°	Prism, dark-violet
V = 1485.9 (9) Å3	0.20 × 0.20 × 0.10 mm
Z = 4

Bruker APEX CCD area-detector diffractometer	1857 independent reflections
Radiation source: fine-focus sealed tube	1739 reflections with I > 2σ(I)
graphite	Rint = 0.046
integration method scans	θmax = 28.3°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Bruker, 2004)	h = −15→15
Tmin = 0.895, Tmax = 0.910	k = −27→27
10203 measured reflections	l = −9→9

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)] = 0.033	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.089	w = 1/[σ2(Fo2) + (0.0395P)2 + 1.1284P] where P = (Fo2 + 2Fc2)/3
S = 1.16	(Δ/σ)max < 0.001
1857 reflections	Δρmax = 0.37 e Å−3
127 parameters	Δρmin = −0.38 e Å−3
2 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0065 (6)

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.

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.

	x	y	z	Uiso*/Ueq
Cr1	0.0000	0.148676 (17)	0.2500	0.02141 (14)
O1	0.10432 (13)	0.15066 (6)	0.5670 (2)	0.0278 (3)
H1A	0.1841 (11)	0.1603 (11)	0.618 (4)	0.038 (6)*
H1B	0.097 (2)	0.1194 (8)	0.626 (3)	0.039 (6)*
O2	0.11598 (12)	0.22143 (6)	0.2606 (2)	0.0273 (3)
O3	0.10971 (12)	0.07688 (6)	0.2448 (2)	0.0275 (3)
O4	0.12757 (13)	0.33040 (6)	0.2756 (2)	0.0324 (3)
O5	0.11585 (14)	−0.03196 (7)	0.2324 (2)	0.0394 (4)
C1	0.06468 (17)	0.01913 (8)	0.2430 (3)	0.0259 (4)
C2	0.07080 (16)	0.27821 (8)	0.2608 (3)	0.0236 (3)
N11	0.5000	0.15711 (11)	0.2500	0.0374 (5)
N12	0.5000	−0.04417 (12)	0.2500	0.0393 (6)
H12	0.5000	−0.0864	0.2500	0.096 (17)*
C11	0.3808 (3)	0.19340 (12)	0.2074 (5)	0.0594 (7)
H11C	0.3998	0.2396	0.2191	0.121 (15)*
H11D	0.3548	0.1811	0.3077	0.088 (11)*
H11E	0.3087	0.1836	0.0671	0.077 (10)*
C12	0.5000	0.09124 (12)	0.2500	0.0263 (5)
C13	0.38704 (18)	0.05453 (10)	0.2186 (3)	0.0341 (4)
H13	0.3097	0.0760	0.1967	0.049 (7)*
C14	0.3915 (2)	−0.01145 (10)	0.2204 (3)	0.0394 (5)
H14	0.3167	−0.0349	0.2005	0.070 (9)*

	U11	U22	U33	U12	U13	U23
Cr1	0.0191 (2)	0.0153 (2)	0.0318 (2)	0.000	0.01434 (16)	0.000
O1	0.0272 (7)	0.0222 (6)	0.0332 (7)	−0.0025 (5)	0.0147 (6)	0.0010 (5)
O2	0.0237 (6)	0.0200 (6)	0.0417 (7)	−0.0003 (4)	0.0192 (6)	0.0007 (5)
O3	0.0236 (6)	0.0222 (6)	0.0400 (7)	0.0021 (5)	0.0186 (5)	−0.0004 (5)
O4	0.0275 (6)	0.0205 (6)	0.0477 (8)	−0.0031 (5)	0.0180 (6)	0.0019 (5)
O5	0.0379 (8)	0.0254 (7)	0.0459 (8)	0.0093 (5)	0.0148 (6)	−0.0056 (6)
C1	0.0242 (8)	0.0219 (8)	0.0252 (8)	0.0029 (6)	0.0080 (7)	−0.0011 (6)
C2	0.0216 (8)	0.0216 (8)	0.0258 (8)	0.0007 (6)	0.0110 (6)	0.0014 (6)
N11	0.0452 (14)	0.0244 (11)	0.0443 (14)	0.000	0.0240 (12)	0.000
N12	0.0497 (15)	0.0244 (12)	0.0397 (13)	0.000	0.0198 (11)	0.000
C11	0.0716 (18)	0.0393 (13)	0.0646 (16)	0.0220 (12)	0.0327 (15)	−0.0016 (11)
C12	0.0265 (12)	0.0271 (12)	0.0259 (11)	0.000	0.0138 (10)	0.000
C13	0.0248 (9)	0.0395 (10)	0.0398 (10)	−0.0006 (7)	0.0178 (8)	−0.0021 (8)
C14	0.0376 (11)	0.0398 (11)	0.0399 (11)	−0.0139 (8)	0.0190 (9)	−0.0035 (8)

Cr1—O3i	1.9466 (13)	N11—C12	1.342 (3)
Cr1—O3	1.9466 (13)	N11—C11ii	1.447 (3)
Cr1—O2	1.9706 (13)	N11—C11	1.447 (3)
Cr1—O2i	1.9706 (13)	N12—C14ii	1.333 (3)
Cr1—O1i	2.0067 (14)	N12—C14	1.333 (3)
Cr1—O1	2.0067 (14)	N12—H12	0.8600
O1—H1A	0.821 (10)	C11—H11C	0.9600
O1—H1B	0.802 (10)	C11—H11D	0.9600
O2—C2	1.269 (2)	C11—H11E	0.9600
O3—C1	1.283 (2)	C12—C13	1.414 (2)
O4—C2	1.224 (2)	C12—C13ii	1.414 (2)
O5—C1	1.218 (2)	C13—C14	1.345 (3)
C1—C1i	1.546 (4)	C13—H13	0.9300
C2—C2i	1.557 (3)	C14—H14	0.9300
O3i—Cr1—O3	82.57 (8)	O4—C2—C2i	119.61 (10)
O3i—Cr1—O2	177.08 (5)	O2—C2—C2i	114.16 (9)
O3—Cr1—O2	97.57 (6)	C12—N11—C11ii	120.73 (15)
O3i—Cr1—O2i	97.57 (6)	C12—N11—C11	120.73 (15)
O3—Cr1—O2i	177.08 (5)	C11ii—N11—C11	118.5 (3)
O2—Cr1—O2i	82.45 (7)	C14ii—N12—C14	120.0 (3)
O3i—Cr1—O1i	91.57 (5)	C14ii—N12—H12	120.0
O3—Cr1—O1i	90.16 (5)	C14—N12—H12	120.0
O2—Cr1—O1i	91.35 (5)	N11—C11—H11C	109.5
O2i—Cr1—O1i	86.91 (5)	N11—C11—H11D	109.5
O3i—Cr1—O1	90.16 (5)	H11C—C11—H11D	109.5
O3—Cr1—O1	91.57 (5)	N11—C11—H11E	109.5
O2—Cr1—O1	86.91 (5)	H11C—C11—H11E	109.5
O2i—Cr1—O1	91.35 (5)	H11D—C11—H11E	109.5
O1i—Cr1—O1	177.70 (7)	N11—C12—C13	121.92 (12)
Cr1—O1—H1A	114.1 (17)	N11—C12—C13ii	121.92 (12)
Cr1—O1—H1B	116.7 (17)	C13—C12—C13ii	116.2 (2)
H1A—O1—H1B	110 (2)	C14—C13—C12	119.97 (19)
C2—O2—Cr1	114.53 (11)	C14—C13—H13	120.0
C1—O3—Cr1	115.20 (11)	C12—C13—H13	120.0
O5—C1—O3	125.28 (17)	N12—C14—C13	121.95 (19)
O5—C1—C1i	121.26 (11)	N12—C14—H14	119.0
O3—C1—C1i	113.46 (9)	C13—C14—H14	119.0
O4—C2—O2	126.23 (15)
O3i—Cr1—O2—C2	−89.0 (10)	Cr1—O3—C1—C1i	−3.0 (2)
O3—Cr1—O2—C2	178.46 (12)	Cr1—O2—C2—O4	176.72 (14)
O2i—Cr1—O2—C2	1.40 (9)	Cr1—O2—C2—C2i	−3.4 (2)
O1i—Cr1—O2—C2	88.11 (12)	C11ii—N11—C12—C13	177.00 (16)
O1—Cr1—O2—C2	−90.37 (12)	C11—N11—C12—C13	−3.00 (16)
O3i—Cr1—O3—C1	1.22 (9)	C11ii—N11—C12—C13ii	−3.00 (16)
O2—Cr1—O3—C1	178.27 (12)	C11—N11—C12—C13ii	177.00 (16)
O2i—Cr1—O3—C1	−91.7 (10)	N11—C12—C13—C14	−179.79 (14)
O1i—Cr1—O3—C1	−90.34 (12)	C13ii—C12—C13—C14	0.21 (14)
O1—Cr1—O3—C1	91.18 (12)	C14ii—N12—C14—C13	0.22 (15)
Cr1—O3—C1—O5	177.34 (15)	C12—C13—C14—N12	−0.4 (3)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1A···O4iii	0.82 (1)	1.91 (1)	2.719 (2)	171 (2)
O1—H1B···O5iv	0.80 (1)	1.91 (1)	2.680 (2)	160 (2)
N12—H12···O4v	0.86	2.19	2.906 (3)	141
N12—H12···O4vi	0.86	2.19	2.906 (3)	141

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1A⋯O4i	0.82 (1)	1.91 (1)	2.719 (2)	171 (2)
O1—H1B⋯O5ii	0.80 (1)	1.91 (1)	2.680 (2)	160 (2)
N12—H12⋯O4iii	0.86	2.19	2.906 (3)	141
N12—H12⋯O4iv	0.86	2.19	2.906 (3)	141

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