Imidazolium trans-di­aqua­dioxalato­chromate(III) dihydrate

Chérif, I.; Abdelhak, J.; Zid, M.F.; Driss, A.

doi:10.1107/S160053681303078X

metal-organic compounds

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Volume 69| Part 12| December 2013| Pages m667-m668

doi:10.1107/S160053681303078X

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Imidazolium trans-diaquadioxalatochromate(III) dihydrate

Ichraf Chérif,^a ^* Jawher Abdelhak,^a Mohamed Faouzi Zid ^a and Ahmed Driss ^a

^aLaboratoire de Matériaux et Cristallochimie, Faculté des Sciences de Tunis, Université de Tunis El Manar, 2092 Manar II Tunis, Tunisia
^*Correspondence e-mail: cherif.ichraf@yahoo.fr

(Received 3 November 2013; accepted 8 November 2013; online 16 November 2013)

In the title hydrated molecular salt, (C₃H₅N₂)[Cr(C₂O₄)₂(H₂O)₂]·2H₂O, the complete cation is generated by a crystallographic twofold rotation axis, with one C atom lying on the rotation axis. The complete anion is generated by crystallographic inversion symmetry (Cr^III site symmetry -1), to generate a slightly distorted CrO₆ octahedron with trans water molecules and chelating oxalate dianions. The oxalate ion is almost planar (r.m.s. deviation = 0.017 Å) and the five-membered chelate ring is a shallow envelope with the metal ion displaced by 0.126 (1) Å from the ligand atoms. The crystal structure features O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds, which link the components into a three-dimensional network.

CCDC reference: 802679

Related literature

For a related structure and background to oxalate complexes, see: Chérif et al. (2012 ). For the structures of salts containing the [Cr(C₂O₄)₂(H₂O)₂]⁻ anion with various cations, see: Bélombé et al. (2009 ); Nenwa et al. (2010 ); Chérif et al. (2011 ); Kahlenberg et al. (2011 ). For geometric parameters of the imidazolium cation, see: Zhu (2012 ); Smith & Wermuth (2010 ).

Experimental

Crystal data

(C₃H₅N₂)[Cr(C₂O₄)₂(H₂O)₂]·2H₂O
M_r = 369.19
Monoclinic, C 2/c
a = 10.836 (1) Å
b = 7.5409 (7) Å
c = 16.349 (3) Å
β = 93.52 (1)°
V = 1333.4 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.93 mm⁻¹
T = 298 K
0.6 × 0.4 × 0.3 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
Absorption correction: ψ scan (North et al., 1968 ) T_min = 0.647, T_max = 0.757
1848 measured reflections
1452 independent reflections
1369 reflections with I > 2σ(I)
R_int = 0.011
2 standard reflections every 120 min intensity decay: 2.2%

Refinement

R[F² > 2σ(F²)] = 0.029
wR(F²) = 0.086
S = 1.12
1452 reflections
124 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.55 e Å⁻³
Δρ_min = −0.39 e Å⁻³

Table 1
Selected bond lengths (Å)

Cr—O3	1.963 (1)
Cr—O2	1.967 (1)
Cr—O1	1.979 (2)

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O6—H1⋯O4ⁱ	0.80 (3)	2.20 (3)	2.984 (2)	168 (3)
O6—H4⋯O4ⁱⁱ	0.72 (3)	2.16 (3)	2.878 (2)	174 (4)
O1—H2⋯O5ⁱⁱⁱ	0.79 (3)	1.93 (3)	2.717 (2)	173 (3)
O1—H3⋯O6^iv	0.85 (3)	1.75 (3)	2.601 (2)	176 (3)
N1—H5⋯O3	1.04 (4)	2.07 (3)	2.926 (2)	137 (2)
C3—H7⋯O2^iv	0.93	2.25	3.088 (3)	150
Symmetry codes: (i) x, y+1, z; (ii) $[-x+{\script{3\over 2}}, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (iii) $[x-{\script{1\over 2}}, y+{\script{1\over 2}}, z]$ ; (iv) $[-x+{\script{3\over 2}}, -y+{\script{1\over 2}}, -z+1]$ .

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 & Putz, 1999 ); software used to prepare material for publication: WinGX (Farrugia, 2012 ).

Supporting information

CCDC reference: 802679

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053681303078X/hb7157sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S160053681303078X/hb7157Isup2.hkl

checkCIF report

Comment top

As part of our ongoing studies of new bis(oxalato)chromate(III) species of general formula (organic cation)[Cr(C₂O₄)₂(H₂O)₂].nH₂O (Chérif et al., 2012), we now describe the synthesis and structure of the title compound, (I).

The asymmetric unit of (I) is formed by one-half cation, one half anion and one water molecule of crystallization (Fig. 1). The Cr^+III ion lies on an inversion center and the C and H atoms of C(4)—H(6) groups lie on twofold rotation axis. In the anionic complex, the coordination environment of Cr^+III ion involves six oxygen atoms (two from trans water molecules and four from two chelating oxalate dianion) in a slightly distorted octahedral geometry. The main distortion of the CrO₆ octahedron is associated to the reduction from the ideal 90° value of some bond angles [83.11 (5)° for O(3)—Cr—O(2) and O(3)ⁱ—Cr—O(2)ⁱ]. The equatorial Cr—O_(ox) distances are very similar, 1.963 (1) Å [Cr—O(3), Cr—O(3)ⁱ] and 1.967 (1) Å [Cr—O(2), Cr—O(2)ⁱ], and they are comparable with the values reported for similar compounds containing the [Cr(C₂O₄)₂(H₂O)₂]^- motif completed with various uncoordinated cations including quinolinium: [C₉H₈N][Cr(H₂O)₂(C₂O₄)₂] (Bélombé et al., 2009), 4-dimethylaminopyridinium: [C₇H₁₁N₂][Cr(C₂O₄)₂(H₂O)₂] (Nenwa et al., 2010), 4-aminopyridinium: [C₅H₇N₂][Cr(C₂O₄)₂(H₂O)₂]·H₂O (Chérif et al., 2011), 1-ethyl-3-methylimidazolium: [EMIm][Cr(C₂O₄)₂(H₂O)₂] (Kahlenberg et al., 2011) and 3-aminopyridinium (C₅H₇N₂)[Cr(C₂O₄)₂(H₂O)₂] (Chérif et al., 2012). The axial Cr—O_(water) distances of 1.979 (2) Å are somewhat longer than the Cr—O_(ox) ones but significantly shorter than those for compounds already mentioned. As far as the imidazolium cations are concerned, the C—N [1.363 (3) Å for N(1)—C(4) and N(1)ⁱⁱ—C(4), 1.295 (3) Å for N(1)—C(3) and N(1)ⁱⁱ—C(3)ⁱⁱ] and C—C bond lengths of 1.315 (4) Å for C(3)—C(3)ⁱⁱ, agree with those reported for similar compounds (Zhu, 2012; Smith & Wermuth, 2010).

Within the crystal structure, hydrogen bonds consisting of O—H···O, N—H···O and C—H···O interactions contribute to the cohesion of the packing (Fig. 2). In fact, for the O—H···O hydrogen bonds, the uncoordinated water molecules [O(6)] play a role as both acceptors and donors while the coordinated one [O(1)] act only as donors. Finally, the [Cr(C₂O₄)₂(H₂O)₂]^- anions and (C₃H₅N₂)⁺ cations are linked through N(1)—H(5)···O(3) and C(3)—H(7)···O(2) interactions. As a consequence, the overall hydrogen-bonded scheme can be described as a three-dimensional network.

Related literature top

For a related structure and background to oxalate complexes, see: Chérif et al. (2012). For the structures of salts containing the [Cr(C₂O₄)₂(H₂O)₂]^- anion with various cations, see: Bélombé et al. (2009); Nenwa et al. (2010); Chérif et al. (2011); Kahlenberg et al. (2011). For geometric parameters of the imidazolium cation, see: Zhu (2012); Smith & Wermuth (2010).

Experimental top

A mixture of imidazole (1 mmol), oxalic acid dihydrate (2 mmol) and Cr(NO₃)₃·9H₂O (1 mmol) was dissolved in 40 ml of water. The resulting solution was then stirred for 2 h and allowed to evaporate at room temperature. After two months, violet prisms of (I) were obtained.

Computing details top

Data collection: CAD-4 EXPRESS (Duisenberg, 1992; Macíček & Yordanov, 1992); cell refinement: CAD-4 EXPRESS (Duisenberg, 1992; Macíček & Yordanov, 1992); 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 & Putz, 1999); software used to prepare material for publication: WinGX (Farrugia, 2012).

Figures top

	Fig. 1. : A view of the title compound with displacement ellipsoids drawn at the 50% probability level for non-H atoms. [Symmetry codes: (i) -x + 3/2,-y + 1/2,-z + 1; (ii) -x + 2,y,-z + 3/2].
	Fig. 2. : Structure projection along b axis showing O—H···O (red dashed lines) and N—H···O (blue dashed lines) hydrogen bonds.

Imidazolium trans-diaquadioxalatochromate(III) dihydrate top

Crystal data top

(C₃H₅N₂)[Cr(C₂O₄)₂(H₂O)₂]·2H₂O	F(000) = 756
M_r = 369.19	D_x = 1.839 Mg m⁻³
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 25 reflections
a = 10.836 (1) Å	θ = 10–15°
b = 7.5409 (7) Å	µ = 0.93 mm⁻¹
c = 16.349 (3) Å	T = 298 K
β = 93.52 (1)°	Prism, violet
V = 1333.4 (3) Å³	0.6 × 0.4 × 0.3 mm
Z = 4

Data collection top

Enraf–Nonius CAD-4 diffractometer	1369 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.011
Graphite monochromator	θ_max = 27.0°, θ_min = 2.5°
ω/2θ scans	h = −13→13
Absorption correction: ψ scan (North et al., 1968)	k = −1→9
T_min = 0.647, T_max = 0.757	l = −20→1
1848 measured reflections	2 standard reflections every 120 min
1452 independent reflections	intensity decay: 2.2%

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.029	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.086	H atoms treated by a mixture of independent and constrained refinement
S = 1.12	w = 1/[σ²(F_o²) + (0.0456P)² + 1.7165P] where P = (F_o² + 2F_c²)/3
1452 reflections	(Δ/σ)_max < 0.001
124 parameters	Δρ_max = 0.55 e Å⁻³
0 restraints	Δρ_min = −0.39 e Å⁻³

Crystal data top

(C₃H₅N₂)[Cr(C₂O₄)₂(H₂O)₂]·2H₂O	V = 1333.4 (3) Å³
M_r = 369.19	Z = 4
Monoclinic, C2/c	Mo Kα radiation
a = 10.836 (1) Å	µ = 0.93 mm⁻¹
b = 7.5409 (7) Å	T = 298 K
c = 16.349 (3) Å	0.6 × 0.4 × 0.3 mm
β = 93.52 (1)°

Data collection top

Enraf–Nonius CAD-4 diffractometer	1369 reflections with I > 2σ(I)
Absorption correction: ψ scan (North et al., 1968)	R_int = 0.011
T_min = 0.647, T_max = 0.757	2 standard reflections every 120 min
1848 measured reflections	intensity decay: 2.2%
1452 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.029	0 restraints
wR(F²) = 0.086	H atoms treated by a mixture of independent and constrained refinement
S = 1.12	Δρ_max = 0.55 e Å⁻³
1452 reflections	Δρ_min = −0.39 e Å⁻³
124 parameters

Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Cr	0.7500	0.2500	0.5000	0.02258 (15)
O2	0.70111 (13)	0.12749 (18)	0.39687 (8)	0.0324 (3)
O3	0.83676 (12)	0.02646 (17)	0.52566 (8)	0.0276 (3)
O4	0.73747 (15)	−0.12361 (19)	0.33002 (9)	0.0387 (4)
O6	0.86780 (17)	0.5293 (2)	0.31972 (10)	0.0402 (4)
C1	0.83297 (15)	−0.0860 (2)	0.46642 (11)	0.0242 (4)
O1	0.59861 (14)	0.1644 (2)	0.54913 (11)	0.0424 (4)
O5	0.88681 (13)	−0.22844 (18)	0.46604 (9)	0.0334 (3)
C2	0.75010 (16)	−0.0264 (2)	0.38993 (11)	0.0264 (4)
C3	0.9690 (2)	0.1333 (3)	0.71415 (13)	0.0372 (5)
H7	0.9425	0.2337	0.6851	0.045*
N1	0.95088 (19)	−0.0291 (4)	0.69055 (13)	0.0575 (6)
C4	1.0000	−0.1396 (5)	0.7500	0.0518 (9)
H1	0.832 (3)	0.618 (4)	0.3298 (18)	0.051 (8)*
H2	0.535 (3)	0.199 (4)	0.5285 (19)	0.055 (8)*
H3	0.606 (3)	0.101 (4)	0.592 (2)	0.056 (8)*
H4	0.837 (3)	0.493 (5)	0.283 (2)	0.072 (12)*
H5	0.910 (4)	−0.078 (5)	0.636 (2)	0.085 (11)*
H6	1.0000	−0.257 (7)	0.7500	0.087 (18)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cr	0.0263 (2)	0.0204 (2)	0.0200 (2)	0.00213 (14)	−0.00693 (15)	0.00055 (13)
O2	0.0411 (7)	0.0286 (7)	0.0257 (6)	0.0078 (6)	−0.0137 (5)	−0.0039 (5)
O3	0.0326 (7)	0.0246 (6)	0.0242 (6)	0.0035 (5)	−0.0095 (5)	0.0005 (5)
O4	0.0485 (8)	0.0352 (8)	0.0306 (7)	0.0058 (6)	−0.0109 (6)	−0.0097 (6)
O6	0.0554 (10)	0.0333 (8)	0.0311 (8)	0.0038 (7)	−0.0030 (7)	−0.0006 (6)
C1	0.0222 (8)	0.0235 (8)	0.0262 (8)	−0.0013 (6)	−0.0029 (6)	0.0014 (7)
O1	0.0296 (8)	0.0528 (10)	0.0441 (9)	0.0015 (7)	−0.0030 (7)	0.0219 (8)
O5	0.0326 (7)	0.0260 (7)	0.0408 (8)	0.0062 (5)	−0.0053 (6)	−0.0010 (6)
C2	0.0277 (8)	0.0267 (9)	0.0242 (8)	−0.0009 (7)	−0.0045 (7)	−0.0010 (7)
C3	0.0401 (11)	0.0382 (11)	0.0335 (10)	0.0124 (9)	0.0040 (8)	0.0118 (9)
N1	0.0402 (10)	0.0946 (19)	0.0362 (10)	0.0027 (11)	−0.0099 (8)	−0.0193 (11)
C4	0.0457 (18)	0.0294 (16)	0.080 (3)	0.000	0.0024 (17)	0.000

Geometric parameters (Å, º) top

Cr—O3ⁱ	1.963 (1)	C1—O5	1.223 (2)
Cr—O3	1.963 (1)	C1—C2	1.560 (2)
Cr—O2	1.967 (1)	O1—H2	0.79 (4)
Cr—O2ⁱ	1.967 (1)	O1—H3	0.85 (3)
Cr—O1ⁱ	1.979 (2)	C3—N1	1.295 (3)
Cr—O1	1.979 (2)	C3—C3ⁱⁱ	1.315 (4)
O2—C2	1.284 (2)	C3—H7	0.9300
O3—C1	1.286 (2)	N1—C4	1.363 (3)
O4—C2	1.224 (2)	N1—H5	1.04 (4)
O6—H1	0.80 (3)	C4—N1ⁱⁱ	1.363 (3)
O6—H4	0.73 (4)	C4—H6	0.89 (5)

O3ⁱ—Cr—O3	180.0	O5—C1—O3	126.15 (16)
O3ⁱ—Cr—O2	96.89 (5)	O5—C1—C2	120.02 (16)
O3—Cr—O2	83.11 (5)	O3—C1—C2	113.83 (14)
O3ⁱ—Cr—O2ⁱ	83.11 (5)	Cr—O1—H2	116 (2)
O3—Cr—O2ⁱ	96.89 (5)	Cr—O1—H3	119 (2)
O2—Cr—O2ⁱ	180.0	H2—O1—H3	125 (3)
O3ⁱ—Cr—O1ⁱ	91.78 (7)	O4—C2—O2	125.83 (17)
O3—Cr—O1ⁱ	88.22 (7)	O4—C2—C1	119.95 (16)
O2—Cr—O1ⁱ	89.52 (7)	O2—C2—C1	114.21 (15)
O2ⁱ—Cr—O1ⁱ	90.48 (7)	N1—C3—C3ⁱⁱ	108.99 (13)
O3ⁱ—Cr—O1	88.22 (7)	N1—C3—H7	125.5
O3—Cr—O1	91.78 (7)	C3ⁱⁱ—C3—H7	125.5
O2—Cr—O1	90.48 (7)	C3—N1—C4	108.7 (2)
O2ⁱ—Cr—O1	89.52 (7)	C3—N1—H5	130 (2)
O1ⁱ—Cr—O1	180.0	C4—N1—H5	122 (2)
C2—O2—Cr	114.16 (11)	N1ⁱⁱ—C4—N1	104.7 (3)
C1—O3—Cr	114.36 (11)	N1ⁱⁱ—C4—H6	127.67 (16)
H1—O6—H4	107 (3)	N1—C4—H6	127.67 (15)

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O6—H1···O4ⁱⁱⁱ	0.80 (3)	2.20 (3)	2.984 (2)	168 (3)
O6—H4···O4^iv	0.72 (3)	2.16 (3)	2.878 (2)	174 (4)
O1—H2···O5^v	0.79 (3)	1.93 (3)	2.717 (2)	173 (3)
O1—H3···O6ⁱ	0.85 (3)	1.75 (3)	2.601 (2)	176 (3)
N1—H5···O3	1.04 (4)	2.07 (3)	2.926 (2)	137 (2)
C3—H7···O2ⁱ	0.93	2.25	3.088 (3)	150

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

Selected bond lengths (Å) top

Cr—O3	1.963 (1)	Cr—O1	1.979 (2)
Cr—O2	1.967 (1)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O6—H1···O4ⁱ	0.80 (3)	2.20 (3)	2.984 (2)	168 (3)
O6—H4···O4ⁱⁱ	0.72 (3)	2.16 (3)	2.878 (2)	174 (4)
O1—H2···O5ⁱⁱⁱ	0.79 (3)	1.93 (3)	2.717 (2)	173 (3)
O1—H3···O6^iv	0.85 (3)	1.75 (3)	2.601 (2)	176 (3)
N1—H5···O3	1.04 (4)	2.07 (3)	2.926 (2)	137 (2)
C3—H7···O2^iv	0.93	2.25	3.088 (3)	150

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

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Volume 69| Part 12| December 2013| Pages m667-m668

doi:10.1107/S160053681303078X

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