metal-organic compounds
μ-Pyrazine-bis[tetraaquacadmium(II)] μ-pyrazine-bis[tetraacetatocadmium(II)]
aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, bDepartment of Chemistry, Faculty of Science, Prince of Songkla University, Hat-Yai, Songkhla 90112, Thailand, and cDepartment of Science, Payame Noor University, Zanjan, Iran
*Correspondence e-mail: hkfun@usm.my
In the title dinuclear ionic complex, [Cd2(C4H4N2)(H2O)8][Cd2(CH3CO2)8(C4H4N2)], the cation and anion are disordered equally over a site with symmetry mmm. The CdII ions and the N atoms of the bridging pyrazine ligand lie on the intersection of two crystallographic mirror planes. The C atoms of the bridging pyrazine ligand lie on one of these mirror planes, and the acetate groups and water molecules lie across the intersecting mirror planes. Each CdII atom in the cation is five-coordinated by four O atoms from four water molecules and one N atom from the bridging pyrazine ligand, whereas each CdII in the anion is nine-coordinated by four pairs of O atoms from the bidentate acetate ligands and one N atom from the bridging pyrazine ligand. In the each anion is surrounded by eight nearest-neighbour cations and vice versa. The is stabilized by ionic interactions as well as by C—H⋯O interactions.
Related literature
For bond-length data, see: Allen et al. (1987). For CdII coordination chemistry, applications and related structures, see: Filipović et al. (2008); Inoue et al. (2000); Pons et al. (2007); Xia et al. (2004).
Experimental
Crystal data
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Refinement
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Data collection: APEX2 (Bruker, 2005); cell APEX2; data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003).
Supporting information
10.1107/S1600536808010994/ci2576sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536808010994/ci2576Isup2.hkl
The title compound was synthesized by mixing Cd(CH3COO)2 and pyrazine with a 2:1 molar ratio in a hot methanol-water (2:1 v/v) solution and stirred for 10 min at room temperature. The solution was then left at ambient temperature to allow the solvent to slowly evaporate. Colourless crystals of the title compound suitable for X-ray
were obtained after a few weeks.Water H atoms were located in a difference map and refined isotropically, with a O—H distance restraint of 0.800 (1) Å. C-bound H atoms were positioned geometrically and allowed to ride on their parent atoms, with C—H = 0.96 Å. The Uiso value of H1A was constrained to 1.2Ueq(C1) and for other H atoms the Uiso values were refined. A rotating group model was used for the methyl group.
Data collection: APEX2 (Bruker, 2005); cell
APEX2 (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2003).[Cd2(C4H4N2)(H2O)8][Cd2(C2H3O2)8(C4H4N2)] | Dx = 1.983 Mg m−3 |
Mr = 1226.26 | Mo Kα radiation, λ = 0.71073 Å |
Tetragonal, I4/mcm | Cell parameters from 1246 reflections |
Hall symbol: -I 4 2c | θ = 1.7–35.0° |
a = 16.7103 (4) Å | µ = 2.13 mm−1 |
c = 7.3533 (2) Å | T = 100 K |
V = 2053.29 (9) Å3 | Needle, colourless |
Z = 2 | 0.58 × 0.08 × 0.05 mm |
F(000) = 1208 |
Bruker SMART APEXII CCD area-detector diffractometer | 1246 independent reflections |
Radiation source: fine-focus sealed tube | 1145 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.037 |
Detector resolution: 8.33 pixels mm-1 | θmax = 35.0°, θmin = 1.7° |
ω scans | h = −26→26 |
Absorption correction: multi-scan (SADABS; Bruker, 2005) | k = −26→26 |
Tmin = 0.371, Tmax = 0.895 | l = −11→11 |
12617 measured reflections |
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)] = 0.016 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.034 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0089P)2 + 1.5621P] where P = (Fo2 + 2Fc2)/3 |
1246 reflections | (Δ/σ)max = 0.002 |
73 parameters | Δρmax = 0.59 e Å−3 |
2 restraints | Δρmin = −0.44 e Å−3 |
[Cd2(C4H4N2)(H2O)8][Cd2(C2H3O2)8(C4H4N2)] | Z = 2 |
Mr = 1226.26 | Mo Kα radiation |
Tetragonal, I4/mcm | µ = 2.13 mm−1 |
a = 16.7103 (4) Å | T = 100 K |
c = 7.3533 (2) Å | 0.58 × 0.08 × 0.05 mm |
V = 2053.29 (9) Å3 |
Bruker SMART APEXII CCD area-detector diffractometer | 1246 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2005) | 1145 reflections with I > 2σ(I) |
Tmin = 0.371, Tmax = 0.895 | Rint = 0.037 |
12617 measured reflections |
R[F2 > 2σ(F2)] = 0.016 | 2 restraints |
wR(F2) = 0.034 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.06 | Δρmax = 0.59 e Å−3 |
1246 reflections | Δρmin = −0.44 e Å−3 |
73 parameters |
Experimental. The data was collected with the Oxford Cyrosystem Cobra low-temperature attachment. |
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 | Occ. (<1) | |
Cd1 | 0.158218 (5) | 0.341782 (5) | 0.0000 | 0.01214 (4) | |
O1 | 0.16811 (7) | 0.21686 (8) | 0.1438 (2) | 0.0156 (2) | 0.50 |
O2 | 0.04830 (8) | 0.27097 (9) | 0.1708 (2) | 0.0183 (3) | 0.50 |
C2 | 0.09773 (11) | 0.21621 (11) | 0.2069 (3) | 0.0144 (3) | 0.50 |
C3 | 0.07138 (12) | 0.14714 (12) | 0.3238 (3) | 0.0212 (4) | 0.50 |
H3A | 0.0344 | 0.1659 | 0.4142 | 0.036 (9)* | 0.50 |
H3B | 0.1172 | 0.1240 | 0.3825 | 0.038 (8)* | 0.50 |
H3C | 0.0458 | 0.1075 | 0.2493 | 0.031 (8)* | 0.50 |
O1W | 0.11198 (8) | 0.28563 (8) | 0.2621 (2) | 0.0170 (3) | 0.50 |
H1W1 | 0.0654 (4) | 0.2746 (17) | 0.262 (4) | 0.020 (7)* | 0.50 |
H2W1 | 0.1447 (16) | 0.2523 (16) | 0.287 (5) | 0.055 (11)* | 0.50 |
N1 | 0.05890 (6) | 0.44110 (6) | 0.0000 | 0.0131 (3) | |
C1 | −0.01905 (7) | 0.42237 (7) | 0.0000 | 0.0144 (2) | |
H1A | −0.0354 | 0.3673 | 0.0000 | 0.017* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cd1 | 0.00955 (4) | 0.00955 (4) | 0.01731 (7) | 0.00080 (4) | 0.000 | 0.000 |
O1 | 0.0119 (5) | 0.0133 (5) | 0.0216 (7) | 0.0003 (4) | 0.0008 (5) | 0.0015 (5) |
O2 | 0.0137 (6) | 0.0151 (6) | 0.0260 (8) | 0.0028 (5) | 0.0007 (6) | 0.0037 (5) |
C2 | 0.0131 (7) | 0.0118 (7) | 0.0181 (8) | −0.0016 (5) | −0.0025 (6) | 0.0004 (6) |
C3 | 0.0189 (9) | 0.0195 (9) | 0.0251 (10) | −0.0014 (7) | 0.0006 (7) | 0.0074 (8) |
O1W | 0.0121 (5) | 0.0156 (6) | 0.0233 (7) | 0.0022 (5) | 0.0023 (5) | 0.0030 (5) |
N1 | 0.0119 (4) | 0.0119 (4) | 0.0155 (7) | 0.0010 (5) | 0.000 | 0.000 |
C1 | 0.0122 (5) | 0.0113 (5) | 0.0196 (6) | 0.0004 (4) | 0.000 | 0.000 |
Cd1—O1W | 2.2782 (15) | O1—C2 | 1.264 (2) |
Cd1—O1Wi | 2.2783 (15) | O2—C2 | 1.261 (2) |
Cd1—O1Wii | 2.2783 (15) | C2—C3 | 1.505 (3) |
Cd1—O1Wiii | 2.2783 (15) | C3—H3A | 0.96 |
Cd1—O1 | 2.3458 (14) | C3—H3B | 0.96 |
Cd1—O1i | 2.3458 (14) | C3—H3C | 0.96 |
Cd1—O1ii | 2.3458 (14) | O1W—H1W1 | 0.800 (1) |
Cd1—O1iii | 2.3458 (14) | O1W—H2W1 | 0.800 (1) |
Cd1—N1 | 2.3470 (15) | N1—C1i | 1.3396 (15) |
Cd1—O2i | 2.5200 (14) | N1—C1 | 1.3397 (15) |
Cd1—O2ii | 2.5200 (14) | C1—C1iv | 1.384 (2) |
Cd1—O2 | 2.5200 (14) | C1—H1A | 0.96 |
O1W—Cd1—O1Wi | 64.15 (8) | O1i—Cd1—O2ii | 81.84 (5) |
O1W—Cd1—O1Wii | 174.10 (7) | O1ii—Cd1—O2ii | 53.77 (4) |
O1Wi—Cd1—O1Wii | 115.52 (8) | O1iii—Cd1—O2ii | 113.02 (5) |
O1W—Cd1—O1Wiii | 115.51 (8) | N1—Cd1—O2ii | 79.43 (3) |
O1Wi—Cd1—O1Wiii | 174.10 (7) | O2i—Cd1—O2ii | 59.77 (8) |
O1Wii—Cd1—O1Wiii | 64.15 (8) | O1—Cd1—O2 | 53.77 (4) |
O1—Cd1—O1i | 70.82 (6) | O1i—Cd1—O2 | 113.02 (5) |
O1—Cd1—O1ii | 94.46 (6) | O1ii—Cd1—O2 | 147.15 (4) |
O1i—Cd1—O1ii | 53.57 (7) | O1iii—Cd1—O2 | 81.84 (5) |
O1—Cd1—O1iii | 53.57 (7) | N1—Cd1—O2 | 79.43 (3) |
O1i—Cd1—O1iii | 94.46 (6) | O2i—Cd1—O2 | 115.86 (8) |
O1ii—Cd1—O1iii | 70.82 (6) | O2ii—Cd1—O2 | 158.87 (6) |
O1W—Cd1—N1 | 92.95 (3) | C2—O1—Cd1 | 96.17 (11) |
O1Wi—Cd1—N1 | 92.95 (3) | C2—O2—Cd1 | 88.18 (11) |
O1Wii—Cd1—N1 | 92.95 (3) | O2—C2—O1 | 121.73 (17) |
O1Wiii—Cd1—N1 | 92.95 (3) | O2—C2—C3 | 119.02 (16) |
O1—Cd1—N1 | 132.77 (3) | O1—C2—C3 | 119.23 (16) |
O1i—Cd1—N1 | 132.77 (3) | Cd1—O1W—H1W1 | 115 (2) |
O1ii—Cd1—N1 | 132.77 (3) | Cd1—O1W—H2W1 | 104 (3) |
O1iii—Cd1—N1 | 132.77 (3) | H1W1—O1W—H2W1 | 120 (3) |
O1—Cd1—O2i | 113.02 (5) | C1i—N1—C1 | 117.01 (15) |
O1i—Cd1—O2i | 53.77 (4) | C1i—N1—Cd1 | 121.49 (8) |
O1ii—Cd1—O2i | 81.84 (5) | C1—N1—Cd1 | 121.49 (8) |
O1iii—Cd1—O2i | 147.15 (4) | N1—C1—C1iv | 121.50 (8) |
N1—Cd1—O2i | 79.43 (3) | N1—C1—H1A | 120.0 |
O1—Cd1—O2ii | 147.15 (4) | C1iv—C1—H1A | 118.5 |
O1i—Cd1—O1—C2 | 137.93 (10) | O1Wiii—Cd1—N1—C1i | −122.12 (4) |
O1ii—Cd1—O1—C2 | −173.19 (14) | O1—Cd1—N1—C1i | 142.13 (5) |
O1iii—Cd1—O1—C2 | −111.03 (11) | O1i—Cd1—N1—C1i | 37.87 (5) |
N1—Cd1—O1—C2 | 6.81 (14) | O1ii—Cd1—N1—C1i | −37.87 (5) |
O2i—Cd1—O1—C2 | 103.79 (12) | O1iii—Cd1—N1—C1i | −142.13 (5) |
O2ii—Cd1—O1—C2 | 173.28 (11) | O2i—Cd1—N1—C1i | 30.46 (4) |
O2—Cd1—O1—C2 | −2.25 (11) | O2ii—Cd1—N1—C1i | −30.46 (4) |
O1—Cd1—O2—C2 | 2.24 (11) | O2—Cd1—N1—C1i | 149.54 (4) |
O1i—Cd1—O2—C2 | −38.85 (13) | O1W—Cd1—N1—C1 | −57.88 (4) |
O1ii—Cd1—O2—C2 | 19.05 (17) | O1Wi—Cd1—N1—C1 | −122.12 (4) |
O1iii—Cd1—O2—C2 | 52.55 (12) | O1Wii—Cd1—N1—C1 | 122.12 (4) |
N1—Cd1—O2—C2 | −171.01 (12) | O1Wiii—Cd1—N1—C1 | 57.88 (4) |
O2i—Cd1—O2—C2 | −98.33 (12) | O1—Cd1—N1—C1 | −37.87 (5) |
O2ii—Cd1—O2—C2 | −171.01 (12) | O1i—Cd1—N1—C1 | −142.13 (5) |
Cd1—O2—C2—O1 | −3.94 (19) | O1ii—Cd1—N1—C1 | 142.13 (5) |
Cd1—O2—C2—C3 | 177.83 (17) | O1iii—Cd1—N1—C1 | 37.87 (5) |
Cd1—O1—C2—O2 | 4.3 (2) | O2i—Cd1—N1—C1 | −149.54 (4) |
Cd1—O1—C2—C3 | −177.52 (16) | O2ii—Cd1—N1—C1 | 149.54 (4) |
O1W—Cd1—N1—C1i | 122.12 (4) | O2—Cd1—N1—C1 | −30.46 (4) |
O1Wi—Cd1—N1—C1i | 57.88 (4) | C1i—N1—C1—C1iv | 0.0 |
O1Wii—Cd1—N1—C1i | −57.88 (4) | Cd1—N1—C1—C1iv | 180.0 |
Symmetry codes: (i) −y+1/2, −x+1/2, z; (ii) −y+1/2, −x+1/2, −z; (iii) x, y, −z; (iv) y−1/2, x+1/2, −z. |
D—H···A | D—H | H···A | D···A | D—H···A |
C1—H1A···O2 | 0.96 | 2.47 | 3.0405 (18) | 118 |
C1—H1A···O1Wv | 0.96 | 2.56 | 3.2700 (17) | 131 |
C1—H1A···O2iii | 0.96 | 2.47 | 3.0405 (18) | 118 |
C1—H1A···O1Wvi | 0.96 | 2.56 | 3.2700 (17) | 131 |
Symmetry codes: (iii) x, y, −z; (v) −x, y, −z+1/2; (vi) −x, y, z−1/2. |
Experimental details
Crystal data | |
Chemical formula | [Cd2(C4H4N2)(H2O)8][Cd2(C2H3O2)8(C4H4N2)] |
Mr | 1226.26 |
Crystal system, space group | Tetragonal, I4/mcm |
Temperature (K) | 100 |
a, c (Å) | 16.7103 (4), 7.3533 (2) |
V (Å3) | 2053.29 (9) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 2.13 |
Crystal size (mm) | 0.58 × 0.08 × 0.05 |
Data collection | |
Diffractometer | Bruker SMART APEXII CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2005) |
Tmin, Tmax | 0.371, 0.895 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 12617, 1246, 1145 |
Rint | 0.037 |
(sin θ/λ)max (Å−1) | 0.807 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.016, 0.034, 1.06 |
No. of reflections | 1246 |
No. of parameters | 73 |
No. of restraints | 2 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.59, −0.44 |
Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2003).
D—H···A | D—H | H···A | D···A | D—H···A |
C1—H1A···O2 | 0.96 | 2.47 | 3.0405 (18) | 118 |
C1—H1A···O1Wi | 0.96 | 2.56 | 3.2700 (17) | 131 |
C1—H1A···O2ii | 0.96 | 2.47 | 3.0405 (18) | 118 |
C1—H1A···O1Wiii | 0.96 | 2.56 | 3.2700 (17) | 131 |
Symmetry codes: (i) −x, y, −z+1/2; (ii) x, y, −z; (iii) −x, y, z−1/2. |
Footnotes
‡Additional correspondence author, e-mail: suchada.c@psu.ac.th.
Acknowledgements
The authors thank the Malaysian Government and Universiti Sains Malaysia for the Scientific Advancement Grant Allocation (SAGA) grant No. 304/PFIZIK/653003/A118. SC thanks Prince of Songkla University for generous support.
References
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This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
The investigations of coordination compounds between cadmium(II) and O and N donors atoms have attracted much attention due to their potential application in a number of areas (Inoue et al., 2000; Pons et al., 2007; Xia et al., 2004), including cytotoxic activities (Filipović et al., 2008). We report herein, the synthesis and crystal structure of the title compound which exhibits a mixed coordination for CdII atom i.e nine- and five-coordination mode for CdII, which is a rare case.
In the title compound, both [Cd2(H2O)8(C4H4N2)]4+ cations and [Cd2(CH3CO2)8(C4H4N2)]4- anions lie on the site symmetry mmm. The CdII and the N atoms of the bridging pyrazine ligand lie on the intersection of two crystallographic mirror planes, one perpenidicular to the c axis (z = 0) and the other parallel to the c axis and passing through the mid points of the a and b axis. The C atoms of the bridging pyrazine ligand lie on the z = 0 mirror plane, and the acetate groups and water molecules lie across the intersecting mirror planes. There are two molecules of the title complex in the unit cell.
In the structure, the cation contains two CdII ions, eight water molecules and one bridging pyrazine ligand whereas the anion contains two CdII ions, eight acetate and one bridging pyrazine ligands. Each of the CdII in the cation is five-coordinated with four O atoms from four water molecules and one N atom from a bridging pyrazine ligand, whereas each CdII in the anion is nine-coordinated with four pairs of chelate O atoms from the bidentate acetate ligands and one N atom from the bridging pyrazine ligand. The Cd—O(acetate) bond distances are 2.3458 (14) and 2.5200 (14) Å, and the Cd—O(water) and Cd—N distances are 2.2783 (15) Å and 2.3470 (15) Å, respectively. The O(water)—Cd—O(water) bond angles lie in the range 64.15 (8)°-174.10 (7)°, whereas, the O(acetate)—Cd—O(acetate) bond angles are in the range 53.57 (7)°-158.87 (6)°. The N—Cd—O(water) angle is 92.95 (3)° and N—Cd—O(acetate) angles are 132.77 (3)° and 79.43 (3)°, respectively. The geometric parameters are comparable to those reported for other Cd—O and Cd—N donor complexes (Inoue et al., 2000; Pons et al., 2007; Xia et al., 2004).
In the crystal packing (Fig. 2 and Fig.3), each anion is surrounded by eight nearest neighbour cations and vice-versa. The crystal structure is stablized by ionic interactions as well as by weak C—H···O interactions (Table 1).