metal-organic compounds
Pyridinium cis-diaquabis(oxalato-κ2O,O′)chromate(III)
aDepartment of Inorganic Chemistry, University of Yaounde I, POB 812 Yaounde, Cameroon, bHigher Teacher Training College, POB 47, University of Yaounde 1, Cameroon, and cInstitut für Anorganische Chemie, RWTH Aachen, D-52056 Aachen, Germany
*Correspondence e-mail: jnenwa@yahoo.fr
The title compound, (C5H6N)[Cr(C2O4)2(H2O)2], contains one protonated pyridine molecule and one [Cr(C2O4)2(H2O)2]− complex anion in the The CrIII in the complex anion is coordinated in a distorted octahedral environment by two O atoms from two cis water molecules and four O atoms from two chelating oxalate dianions. The crystal packing is stabilized by intermolecular N—H⋯O(oxalate) and O—H⋯O(oxalate) hydrogen bonds and by π–π stacking interactions (centroid–centroid distance = 3.602 Å) between pyridine rings, thereby building up a three-dimensional network.
Related literature
For the structural characterization of organic–inorganic salts containing the [Cr(C2O4)2(H2O)2]− anion, see: Bélombé et al. (2009); Nenwa et al. (2010, 2012); Chérif et al. (2011); Chérif, Abdelhak et al. (2012); Chérif, Zid et al. (2012).
Experimental
Crystal data
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Refinement
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Data collection: SMART (Bruker, 2004); cell 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).
Supporting information
10.1107/S1600536812044303/lr2086sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536812044303/lr2086Isup2.hkl
Pyridine (1 mmol, 79.1 mg) and oxalic acid (2 mmol, 260 mg) were added in successive small portions in an aqueous solution (50 ml) of CrCl3.6H2O (1 mmol, 266.5 mg). The mixture was stirred for 4 h continuously. The final blue-violet solution obtained was left at room temperature and violet crystals suitable for X-ray diffraction were obtained after a few days.
The H atoms were positioned geometrically, with C—H, N—H distances of 0.95 and 0.86 Å respectively, and constrained to ride on their parent atoms, with Uiso(H) = 1.2Ueq(C,N). The water H atoms were initially located in a difference Fourier map and refined with distance restraints of d(O–H1) = 0.83 (2) with all Uiso(H) values refined.
Data collection: SMART (Bruker, 2004); cell
SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); 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).Fig. 1. The asymmetric unit of the title compound with displacement ellipsoids drawn at the 50% probability level. | |
Fig. 2. Crystal packing of the title compound, showing the components linked via N–H···O and O–H···O hydrogen bonds (dashed lines) forming a three-dimensional network. π–π stacking between the protonated pyridine rings is also observed. |
(C5H6N)[Cr(C2O4)2(H2O)2] | F(000) = 700 |
Mr = 344.18 | Dx = 1.842 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P_2ybc | Cell parameters from 3703 reflections |
a = 7.479 (2) Å | θ = 1.7–30.9° |
b = 24.700 (8) Å | µ = 0.98 mm−1 |
c = 7.056 (2) Å | T = 100 K |
β = 107.744 (6)° | Needle, violet |
V = 1241.4 (6) Å3 | 0.15 × 0.04 × 0.04 mm |
Z = 4 |
Bruker SMART APEX CCD diffractometer | 3703 independent reflections |
Radiation source: fine-focus sealed tube | 2580 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.106 |
ϕ and ω scans | θmax = 30.9°, θmin = 1.7° |
Absorption correction: multi-scan (SADABS; Bruker, 2004) | h = −10→10 |
Tmin = 0.862, Tmax = 0.961 | k = −34→33 |
18649 measured reflections | l = −9→10 |
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)] = 0.061 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.160 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.13 | w = 1/[σ2(Fo2) + (0.0636P)2] where P = (Fo2 + 2Fc2)/3 |
3703 reflections | (Δ/σ)max = 0.001 |
206 parameters | Δρmax = 0.59 e Å−3 |
5 restraints | Δρmin = −0.69 e Å−3 |
(C5H6N)[Cr(C2O4)2(H2O)2] | V = 1241.4 (6) Å3 |
Mr = 344.18 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 7.479 (2) Å | µ = 0.98 mm−1 |
b = 24.700 (8) Å | T = 100 K |
c = 7.056 (2) Å | 0.15 × 0.04 × 0.04 mm |
β = 107.744 (6)° |
Bruker SMART APEX CCD diffractometer | 3703 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2004) | 2580 reflections with I > 2σ(I) |
Tmin = 0.862, Tmax = 0.961 | Rint = 0.106 |
18649 measured reflections |
R[F2 > 2σ(F2)] = 0.061 | 5 restraints |
wR(F2) = 0.160 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.13 | Δρmax = 0.59 e Å−3 |
3703 reflections | Δρmin = −0.69 e Å−3 |
206 parameters |
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 | ||
Cr1 | 0.00150 (8) | 0.67285 (2) | 0.06297 (8) | 0.00840 (15) | |
C11 | −0.3839 (5) | 0.67581 (15) | −0.0409 (5) | 0.0119 (7) | |
C12 | −0.3217 (5) | 0.73552 (14) | −0.0479 (5) | 0.0099 (7) | |
C21 | 0.0773 (5) | 0.61425 (14) | −0.2335 (5) | 0.0110 (7) | |
C22 | 0.1456 (5) | 0.57906 (15) | −0.0428 (5) | 0.0120 (7) | |
O11 | −0.2502 (3) | 0.64143 (10) | 0.0020 (4) | 0.0113 (5) | |
O12 | −0.1425 (3) | 0.74032 (10) | −0.0051 (4) | 0.0105 (5) | |
O13 | −0.4367 (4) | 0.77229 (11) | −0.0905 (4) | 0.0177 (6) | |
O14 | −0.5518 (4) | 0.66425 (11) | −0.0766 (4) | 0.0170 (6) | |
O21 | 0.0065 (3) | 0.65975 (10) | −0.2098 (4) | 0.0113 (5) | |
O22 | 0.1238 (4) | 0.60185 (10) | 0.1125 (4) | 0.0118 (5) | |
O23 | 0.0948 (4) | 0.59673 (10) | −0.3912 (4) | 0.0137 (5) | |
O24 | 0.2113 (4) | 0.53428 (11) | −0.0504 (4) | 0.0186 (6) | |
OW1 | 0.0262 (4) | 0.67909 (11) | 0.3493 (4) | 0.0139 (5) | |
OW2 | 0.2371 (4) | 0.71532 (11) | 0.1053 (4) | 0.0139 (5) | |
N1 | 0.2547 (4) | 0.48994 (13) | −0.3963 (5) | 0.0148 (6) | |
H1 | 0.2081 | 0.5152 | −0.3419 | 0.018* | |
C2 | 0.3312 (6) | 0.44697 (16) | −0.2871 (6) | 0.0177 (8) | |
H2 | 0.3320 | 0.4446 | −0.1553 | 0.021* | |
C3 | 0.2476 (5) | 0.49522 (15) | −0.5870 (6) | 0.0147 (7) | |
H3 | 0.1927 | 0.5256 | −0.6590 | 0.018* | |
C4 | 0.3220 (6) | 0.45543 (16) | −0.6751 (6) | 0.0172 (8) | |
H4 | 0.3164 | 0.4583 | −0.8082 | 0.021* | |
C5 | 0.4083 (5) | 0.40652 (15) | −0.3686 (6) | 0.0180 (8) | |
H5 | 0.4618 | 0.3765 | −0.2930 | 0.022* | |
C6 | 0.4059 (5) | 0.41073 (16) | −0.5641 (6) | 0.0161 (8) | |
H6 | 0.4599 | 0.3839 | −0.6212 | 0.019* | |
H1B | −0.019 (6) | 0.6988 (17) | 0.415 (6) | 0.032 (15)* | |
H2A | 0.310 (5) | 0.721 (2) | 0.214 (4) | 0.033 (15)* | |
H1A | 0.051 (8) | 0.6501 (17) | 0.419 (9) | 0.06 (2)* | |
H2B | 0.296 (6) | 0.700 (2) | 0.040 (6) | 0.06 (2)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cr1 | 0.0108 (3) | 0.0067 (3) | 0.0083 (3) | 0.0012 (2) | 0.0037 (2) | 0.0006 (2) |
C11 | 0.0116 (16) | 0.0135 (17) | 0.0112 (17) | 0.0003 (13) | 0.0043 (13) | 0.0004 (14) |
C12 | 0.0122 (16) | 0.0114 (16) | 0.0052 (16) | 0.0005 (13) | 0.0015 (13) | 0.0007 (12) |
C21 | 0.0141 (17) | 0.0108 (17) | 0.0102 (17) | −0.0011 (13) | 0.0065 (14) | −0.0005 (13) |
C22 | 0.0157 (17) | 0.0120 (17) | 0.0095 (17) | 0.0011 (13) | 0.0056 (14) | 0.0046 (14) |
O11 | 0.0123 (12) | 0.0093 (12) | 0.0129 (13) | −0.0006 (9) | 0.0048 (10) | −0.0011 (9) |
O12 | 0.0116 (12) | 0.0086 (12) | 0.0110 (13) | 0.0004 (9) | 0.0031 (10) | 0.0003 (9) |
O13 | 0.0148 (13) | 0.0116 (13) | 0.0250 (16) | 0.0046 (10) | 0.0035 (11) | 0.0026 (11) |
O14 | 0.0128 (12) | 0.0175 (14) | 0.0222 (15) | −0.0043 (10) | 0.0073 (11) | −0.0070 (11) |
O21 | 0.0132 (12) | 0.0094 (12) | 0.0123 (13) | 0.0012 (9) | 0.0053 (10) | −0.0014 (9) |
O22 | 0.0187 (13) | 0.0109 (13) | 0.0074 (12) | 0.0035 (10) | 0.0061 (10) | 0.0021 (10) |
O23 | 0.0205 (13) | 0.0112 (13) | 0.0109 (13) | 0.0017 (10) | 0.0069 (10) | 0.0004 (10) |
O24 | 0.0351 (16) | 0.0092 (13) | 0.0144 (14) | 0.0103 (11) | 0.0119 (12) | 0.0024 (10) |
OW1 | 0.0217 (14) | 0.0106 (13) | 0.0106 (13) | 0.0050 (11) | 0.0069 (11) | −0.0003 (10) |
OW2 | 0.0108 (12) | 0.0163 (14) | 0.0150 (14) | −0.0020 (10) | 0.0044 (11) | −0.0048 (11) |
N1 | 0.0198 (16) | 0.0104 (15) | 0.0167 (16) | −0.0004 (12) | 0.0090 (13) | −0.0021 (12) |
C2 | 0.028 (2) | 0.0151 (19) | 0.0117 (18) | −0.0035 (16) | 0.0091 (16) | −0.0003 (14) |
C3 | 0.0166 (18) | 0.0114 (17) | 0.0139 (18) | −0.0028 (13) | 0.0013 (14) | 0.0026 (14) |
C4 | 0.024 (2) | 0.0173 (19) | 0.0100 (18) | −0.0015 (15) | 0.0040 (15) | −0.0013 (14) |
C5 | 0.024 (2) | 0.0083 (17) | 0.019 (2) | 0.0024 (14) | 0.0037 (16) | 0.0042 (14) |
C6 | 0.0199 (19) | 0.0129 (18) | 0.017 (2) | 0.0007 (14) | 0.0068 (15) | −0.0062 (14) |
Cr1—O11 | 1.959 (3) | OW1—H1B | 0.814 (19) |
Cr1—O22 | 1.960 (3) | OW1—H1A | 0.86 (5) |
Cr1—O12 | 1.963 (3) | OW2—H2A | 0.806 (19) |
Cr1—O21 | 1.963 (3) | OW2—H2B | 0.818 (19) |
Cr1—OW1 | 1.978 (3) | N1—C2 | 1.334 (5) |
Cr1—OW2 | 1.993 (3) | N1—C3 | 1.337 (5) |
C11—O14 | 1.237 (4) | N1—H1 | 0.8600 |
C11—O11 | 1.276 (4) | C2—C5 | 1.365 (5) |
C11—C12 | 1.552 (5) | C2—H2 | 0.9300 |
C12—O13 | 1.224 (4) | C3—C4 | 1.369 (5) |
C12—O12 | 1.286 (4) | C3—H3 | 0.9300 |
C21—O23 | 1.238 (4) | C4—C6 | 1.388 (5) |
C21—O21 | 1.275 (4) | C4—H4 | 0.9300 |
C21—C22 | 1.552 (5) | C5—C6 | 1.378 (6) |
C22—O24 | 1.218 (4) | C5—H5 | 0.9300 |
C22—O22 | 1.285 (4) | C6—H6 | 0.9300 |
O11—Cr1—O22 | 92.85 (11) | C12—O12—Cr1 | 115.7 (2) |
O11—Cr1—O12 | 82.18 (10) | C21—O21—Cr1 | 114.0 (2) |
O22—Cr1—O12 | 174.30 (11) | C22—O22—Cr1 | 114.4 (2) |
O11—Cr1—O21 | 91.36 (11) | Cr1—OW1—H1B | 135 (3) |
O22—Cr1—O21 | 83.09 (11) | Cr1—OW1—H1A | 117 (4) |
O12—Cr1—O21 | 94.19 (11) | H1B—OW1—H1A | 103 (4) |
O11—Cr1—OW1 | 92.26 (11) | Cr1—OW2—H2A | 123 (4) |
O22—Cr1—OW1 | 89.69 (11) | Cr1—OW2—H2B | 106 (4) |
O12—Cr1—OW1 | 93.28 (11) | H2A—OW2—H2B | 107 (3) |
O21—Cr1—OW1 | 172.08 (11) | C2—N1—C3 | 122.5 (3) |
O11—Cr1—OW2 | 171.04 (11) | C2—N1—H1 | 118.8 |
O22—Cr1—OW2 | 95.79 (11) | C3—N1—H1 | 118.8 |
O12—Cr1—OW2 | 89.07 (11) | N1—C2—C5 | 120.1 (4) |
O21—Cr1—OW2 | 87.33 (11) | N1—C2—H2 | 120.0 |
OW1—Cr1—OW2 | 90.17 (12) | C5—C2—H2 | 120.0 |
O14—C11—O11 | 124.7 (3) | N1—C3—C4 | 119.4 (3) |
O14—C11—C12 | 120.6 (3) | N1—C3—H3 | 120.3 |
O11—C11—C12 | 114.8 (3) | C4—C3—H3 | 120.3 |
O13—C12—O12 | 126.4 (3) | C3—C4—C6 | 119.4 (4) |
O13—C12—C11 | 121.2 (3) | C3—C4—H4 | 120.3 |
O12—C12—C11 | 112.4 (3) | C6—C4—H4 | 120.3 |
O23—C21—O21 | 126.0 (3) | C2—C5—C6 | 119.2 (4) |
O23—C21—C22 | 119.1 (3) | C2—C5—H5 | 120.4 |
O21—C21—C22 | 114.9 (3) | C6—C5—H5 | 120.4 |
O24—C22—O22 | 126.3 (3) | C5—C6—C4 | 119.4 (4) |
O24—C22—C21 | 120.1 (3) | C5—C6—H6 | 120.3 |
O22—C22—C21 | 113.6 (3) | C4—C6—H6 | 120.3 |
C11—O11—Cr1 | 114.8 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O24 | 0.86 | 2.10 | 2.783 (4) | 136 |
N1—H1···O23 | 0.86 | 2.17 | 2.901 (4) | 143 |
OW1—H1B···O12i | 0.81 (2) | 1.94 (2) | 2.720 (4) | 162 (5) |
OW1—H1A···O23ii | 0.86 (5) | 1.84 (5) | 2.680 (4) | 168 (5) |
OW2—H2A···O13iii | 0.81 (2) | 1.98 (3) | 2.732 (4) | 154 (4) |
OW2—H2B···O14iv | 0.82 (2) | 1.83 (2) | 2.639 (4) | 173 (5) |
Symmetry codes: (i) x, −y+3/2, z+1/2; (ii) x, y, z+1; (iii) x+1, −y+3/2, z+1/2; (iv) x+1, y, z. |
Experimental details
Crystal data | |
Chemical formula | (C5H6N)[Cr(C2O4)2(H2O)2] |
Mr | 344.18 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 100 |
a, b, c (Å) | 7.479 (2), 24.700 (8), 7.056 (2) |
β (°) | 107.744 (6) |
V (Å3) | 1241.4 (6) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.98 |
Crystal size (mm) | 0.15 × 0.04 × 0.04 |
Data collection | |
Diffractometer | Bruker SMART APEX CCD diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2004) |
Tmin, Tmax | 0.862, 0.961 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 18649, 3703, 2580 |
Rint | 0.106 |
(sin θ/λ)max (Å−1) | 0.723 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.061, 0.160, 1.13 |
No. of reflections | 3703 |
No. of parameters | 206 |
No. of restraints | 5 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.59, −0.69 |
Computer programs: SMART (Bruker, 2004), SAINT (Bruker, 2004), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 2010), WinGX (Farrugia, 1999).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O24 | 0.86 | 2.10 | 2.783 (4) | 135.5 |
N1—H1···O23 | 0.86 | 2.17 | 2.901 (4) | 142.5 |
OW1—H1B···O12i | 0.814 (19) | 1.94 (2) | 2.720 (4) | 162 (5) |
OW1—H1A···O23ii | 0.86 (5) | 1.84 (5) | 2.680 (4) | 168 (5) |
OW2—H2A···O13iii | 0.806 (19) | 1.98 (3) | 2.732 (4) | 154 (4) |
OW2—H2B···O14iv | 0.818 (19) | 1.83 (2) | 2.639 (4) | 173 (5) |
Symmetry codes: (i) x, −y+3/2, z+1/2; (ii) x, y, z+1; (iii) x+1, −y+3/2, z+1/2; (iv) x+1, y, z. |
Acknowledgements
The authors thank Prof. Barthelemy Nyasse (Organic Chemistry Department, University of Yaounde I) for the donation of pyridine and Tobias Storp (RWTH Aachen) for his technical support during X-ray experiments.
References
Bélombé, M. M., Nenwa, J. & Emmerling, F. (2009). Z. Kristallogr. New Cryst. Struct. 224, 239–240. Google Scholar
Brandenburg, K. (2010). DIAMOND. Crystal Impact GbR, Bonn, Germany. Google Scholar
Bruker (2004). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Chérif, I., Abdelhak, J., Zid, M. F. & Driss, A. (2011). Acta Cryst. E67, m1648–m1649. Web of Science CSD CrossRef IUCr Journals Google Scholar
Chérif, I., Abdelhak, J., Zid, M. F. & Driss, A. (2012). Acta Cryst. E68, m824–m825. CSD CrossRef IUCr Journals Google Scholar
Chérif, I., Zid, M. F., El-Ghozzi, M. & Avignant, D. (2012). Acta Cryst. E68, m900– m901. CSD CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Nenwa, J., Bebga, G., Martin, S., Bélombé, M. M., Mbarki, M. & Fokwa, B. P. T. (2012). Acta Cryst. E68, m1325–m1326. CSD CrossRef CAS IUCr Journals Google Scholar
Nenwa, J., Belombe, M. M., Ngoune, J. & Fokwa, B. P. T. (2010). Acta Cryst. E66, m1410. Web of Science CSD CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
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Recently, we have reported the structure of a few organic-inorganic hybrid salts involving various aromatic iminium cations and the complex anion, [Cr(C2O4)2(H2O)2]- in trans-geometry (Bélombé et al., 2009; Nenwa et al., 2010, 2012). In the present investigation, we wish to report the structure of a homologous salt, containing the complex anion adopting the cis-geometry and protonated pyridinium as a counter cation. This cis-anion which is somewhat less common has been observed in a similar organic-inorganic hybrid salt, with 2-amino-5-chloropyridinium as the organic cation (Chérif, Abdelhak et al., 2012).
The asymmetric unit of the title compound, (C5H6N)[Cr(C2O4)2(H2O)2] which crstallizes in space group P21/c, is shown in Fig. 1. The CrIII site in the complex anion has a distorted octahedral coordination environment build up by two O atoms (OW1, OW2) from two cis water molecules and four O atoms (O11, O12, O21, O22) from two chelating oxalate dianions. The main geometric parameters of the (C5H6N)+ cation are in agreement with those found in salts with similar cationic entities (Bélombé et al., 2009; Nenwa et al., 2010; Nenwa et al., 2012; Chérif et al., 2011; Chérif, Abdelhak et al., 2012; Chérif, Zid et al., 2012). The bond distances in the complex anion (Table 1) are comparable with those reported in the 2-amino-5-chloropyridinium compound (Chérif, Abdelhak et al., 2012). The crystal packing is stabilized by intermolecular N—H···O (oxalate) and O—H···O (oxalate) hydrogen bonds and by π–π stacking interactions [centroid-centroid distance = 3.602 Å] between pyridine rings, thereby building up a three-dimensional network (Table 2, Fig. 2).