metal-organic compounds
Retracted: Diazidobis(2,2′-biimidazole)cobalt(II)
aCollege of Medicine, Henan University, Kaifeng 475003, People's Republic of China, and bCollege of Chemistry and Chemical Engineering, Henan University, Kaifeng 475003, People's Republic of China
*Correspondence e-mail: lisheng0821@sina.com
In the title compound, [Co(N3)2(C6H6N4)2], the CoII atom lies on a centre of inversion and is bonded to two azide ions and two bidentate 2,2′-biimidizole ligands, giving a slightly distorted octahedral CoN6 coordination geometry. In the intermolecular N—H⋯N hydrogen bonds exist between the 2,2′-biimidizole ligands and the azide ions, linking the complexes into sheets.
Related literature
For related literature, see: Rees et al. (1983); Hardman & Lipscomb (1984); Kuo & Makinen (1982); Dworschak & Plapp (1977).
Experimental
Crystal data
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Refinement
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Data collection: APEX2 (Bruker, 2004); cell SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2001); software used to prepare material for publication: SHELXTL.
Supporting information
https://doi.org/10.1107/S1600536807062873/bi2265sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536807062873/bi2265Isup2.hkl
A mixture of CoCl2.2(H2O) (1 mmol), 2,2'-biimidazoline (2 mmol) and NaN3 (2 mmol) in 20 ml me thanol was refluxed for two hours. After cooling, the solution was filtered and the filtrate was evaporated naturally at room temperature. Two day later, red blocks of the title compound were obtained with a yield of 22%. Elemental analysis calculated: C 35.04, H 2.92, N 47.69%; found: C 35.01, H 2.96, N 47.65%.
All H atoms were placed in calculated positions with C—H = 0.93 Å and N—H = 0.86 Å and refined as riding with Uiso(H) = 1.2Ueq(C/N).
The imidazole moiety is of biochemical importance due to its presence in more than 200 metalloenzymes, such as carboxypeptidase A (CPA), carbonic anhydrase (CA), liver alcohol dehydrogenase (LADH), and superoxide dismutase (SOD) (Rees et al., 1983; Hardman & Lipscomb, 1984; Kuo & Makinen, 1982; Dworschak & Plapp, 1977).
In the title compound, the CoII atom occupies an inversion centre, and is hexacoordinated by six N atoms from two chelating ligands of H2bim (2,2'-biimidizole; C6H6N4) and two azide ions, showing a slightly distorted octahedral geometry (Fig. 1). The four N atoms from the chelating H2bim consist of the base and the other two N atoms from two azide ions ocupy the axial positions. In the crystal, intermolecular N—H···N hydrogen bonds between 2,2'-biimidizole ligands and azide ions link the complexes into sheets lying in the (002) planes (Fig. 2).
For related literature, see: Rees et al. (1983); Hardman & Lipscomb (1984); Kuo & Makinen (1982); Dworschak & Plapp (1977).
Data collection: APEX2 (Bruker, 2004); cell
SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2001); software used to prepare material for publication: SHELXTL (Bruker, 2001).[Co(N3)2(C6H6N4)2] | F(000) = 836 |
Mr = 411.29 | Dx = 1.682 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2yc | Cell parameters from 1501 reflections |
a = 12.8085 (10) Å | θ = 2.8–25.5° |
b = 8.7632 (5) Å | µ = 1.09 mm−1 |
c = 14.4793 (5) Å | T = 293 K |
β = 91.913 (1)° | Block, red |
V = 1624.30 (17) Å3 | 0.28 × 0.22 × 0.20 mm |
Z = 4 |
Bruker APEXII CCD diffractometer | 1501 independent reflections |
Radiation source: fine-focus sealed tube | 1246 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.022 |
φ and ω scans | θmax = 25.5°, θmin = 2.8° |
Absorption correction: multi-scan (SADABS; Bruker, 2001) | h = −1→15 |
Tmin = 0.750, Tmax = 0.811 | k = −1→10 |
1961 measured reflections | l = −17→17 |
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) = 0.078 | H-atom parameters constrained |
S = 1.00 | w = 1/[σ2(Fo2) + (0.032P)2 + 0.7528P] where P = (Fo2 + 2Fc2)/3 |
1501 reflections | (Δ/σ)max = 0.016 |
124 parameters | Δρmax = 0.24 e Å−3 |
0 restraints | Δρmin = −0.21 e Å−3 |
[Co(N3)2(C6H6N4)2] | V = 1624.30 (17) Å3 |
Mr = 411.29 | Z = 4 |
Monoclinic, C2/c | Mo Kα radiation |
a = 12.8085 (10) Å | µ = 1.09 mm−1 |
b = 8.7632 (5) Å | T = 293 K |
c = 14.4793 (5) Å | 0.28 × 0.22 × 0.20 mm |
β = 91.913 (1)° |
Bruker APEXII CCD diffractometer | 1501 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2001) | 1246 reflections with I > 2σ(I) |
Tmin = 0.750, Tmax = 0.811 | Rint = 0.022 |
1961 measured reflections |
R[F2 > 2σ(F2)] = 0.029 | 0 restraints |
wR(F2) = 0.078 | H-atom parameters constrained |
S = 1.00 | Δρmax = 0.24 e Å−3 |
1501 reflections | Δρmin = −0.21 e Å−3 |
124 parameters |
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 | ||
Co1 | 0.2500 | −0.2500 | 0.5000 | 0.04053 (15) | |
C1 | 0.08433 (18) | −0.0620 (3) | 0.36274 (15) | 0.0523 (6) | |
H1 | 0.0724 | −0.1298 | 0.3141 | 0.063* | |
C2 | 0.03681 (18) | 0.0756 (3) | 0.37190 (15) | 0.0528 (6) | |
H2 | −0.0126 | 0.1194 | 0.3315 | 0.063* | |
C3 | 0.14622 (17) | 0.0371 (2) | 0.48932 (14) | 0.0433 (5) | |
C4 | 0.21008 (17) | 0.0440 (2) | 0.57427 (14) | 0.0437 (5) | |
C5 | 0.32254 (19) | −0.0319 (3) | 0.67815 (16) | 0.0535 (6) | |
H5 | 0.3710 | −0.0924 | 0.7103 | 0.064* | |
C6 | 0.29414 (19) | 0.1097 (3) | 0.70284 (16) | 0.0556 (6) | |
H6 | 0.3182 | 0.1644 | 0.7543 | 0.067* | |
N1 | 0.15295 (14) | −0.0854 (2) | 0.43678 (12) | 0.0463 (4) | |
N2 | 0.26893 (14) | −0.0737 (2) | 0.59794 (12) | 0.0475 (4) | |
N3 | 0.38297 (15) | −0.1637 (2) | 0.42685 (13) | 0.0521 (5) | |
N4 | 0.39621 (15) | −0.0323 (2) | 0.42133 (13) | 0.0507 (5) | |
N5 | 0.41050 (18) | 0.0987 (2) | 0.41471 (16) | 0.0668 (6) | |
N6 | 0.22221 (15) | 0.1566 (2) | 0.63634 (12) | 0.0506 (5) | |
H6A | 0.1905 | 0.2432 | 0.6348 | 0.061* | |
N7 | 0.07654 (14) | 0.1364 (2) | 0.45280 (12) | 0.0484 (4) | |
H7A | 0.0598 | 0.2230 | 0.4761 | 0.058* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Co1 | 0.0437 (2) | 0.0363 (2) | 0.0409 (2) | 0.01142 (17) | −0.00752 (16) | −0.00494 (16) |
C1 | 0.0524 (13) | 0.0580 (14) | 0.0459 (12) | 0.0139 (11) | −0.0072 (10) | −0.0039 (10) |
C2 | 0.0522 (13) | 0.0585 (15) | 0.0473 (12) | 0.0164 (11) | −0.0055 (10) | 0.0043 (11) |
C3 | 0.0431 (11) | 0.0417 (12) | 0.0452 (11) | 0.0082 (9) | 0.0015 (9) | 0.0009 (9) |
C4 | 0.0455 (11) | 0.0400 (11) | 0.0456 (11) | 0.0047 (10) | 0.0022 (9) | −0.0028 (9) |
C5 | 0.0556 (13) | 0.0536 (14) | 0.0503 (12) | 0.0048 (11) | −0.0100 (10) | −0.0019 (11) |
C6 | 0.0618 (14) | 0.0551 (15) | 0.0491 (12) | −0.0004 (12) | −0.0088 (11) | −0.0091 (11) |
N1 | 0.0474 (10) | 0.0460 (11) | 0.0450 (9) | 0.0112 (9) | −0.0048 (8) | −0.0042 (8) |
N2 | 0.0507 (10) | 0.0442 (10) | 0.0472 (10) | 0.0078 (9) | −0.0065 (8) | −0.0044 (8) |
N3 | 0.0554 (11) | 0.0401 (11) | 0.0605 (11) | 0.0096 (9) | −0.0019 (9) | −0.0036 (9) |
N4 | 0.0488 (11) | 0.0505 (13) | 0.0522 (11) | 0.0128 (9) | −0.0073 (9) | −0.0070 (9) |
N5 | 0.0717 (14) | 0.0417 (12) | 0.0860 (15) | 0.0073 (11) | −0.0101 (12) | −0.0065 (11) |
N6 | 0.0588 (11) | 0.0415 (11) | 0.0514 (10) | 0.0074 (9) | −0.0008 (9) | −0.0070 (8) |
N7 | 0.0531 (11) | 0.0425 (10) | 0.0497 (10) | 0.0148 (9) | 0.0018 (8) | 0.0005 (8) |
Co1—N1 | 2.0945 (17) | C3—C4 | 1.455 (3) |
Co1—N1i | 2.0945 (17) | C4—N2 | 1.316 (3) |
Co1—N2i | 2.1055 (18) | C4—N6 | 1.341 (3) |
Co1—N2 | 2.1055 (18) | C5—C6 | 1.344 (3) |
Co1—N3 | 2.172 (2) | C5—N2 | 1.379 (3) |
Co1—N3i | 2.172 (2) | C5—H5 | 0.930 |
C1—C2 | 1.359 (3) | C6—N6 | 1.373 (3) |
C1—N1 | 1.379 (3) | C6—H6 | 0.930 |
C1—H1 | 0.930 | N3—N4 | 1.167 (3) |
C2—N7 | 1.370 (3) | N4—N5 | 1.167 (3) |
C2—H2 | 0.930 | N6—H6A | 0.860 |
C3—N1 | 1.320 (3) | N7—H7A | 0.860 |
C3—N7 | 1.343 (3) | ||
N1—Co1—N1i | 180.00 (8) | N2—C4—N6 | 110.49 (19) |
N1—Co1—N2i | 99.06 (7) | N2—C4—C3 | 119.23 (19) |
N1i—Co1—N2i | 80.94 (7) | N6—C4—C3 | 130.3 (2) |
N1—Co1—N2 | 80.94 (7) | C6—C5—N2 | 109.7 (2) |
N1i—Co1—N2 | 99.06 (7) | C6—C5—H5 | 125.1 |
N2i—Co1—N2 | 180.0 | N2—C5—H5 | 125.1 |
N1—Co1—N3 | 90.61 (7) | C5—C6—N6 | 105.7 (2) |
N1i—Co1—N3 | 89.39 (7) | C5—C6—H6 | 127.1 |
N2i—Co1—N3 | 90.10 (7) | N6—C6—H6 | 127.1 |
N2—Co1—N3 | 89.90 (7) | C3—N1—C1 | 105.96 (18) |
N1—Co1—N3i | 89.39 (7) | C3—N1—Co1 | 110.93 (13) |
N1i—Co1—N3i | 90.61 (7) | C1—N1—Co1 | 142.74 (16) |
N2i—Co1—N3i | 89.90 (7) | C4—N2—C5 | 106.00 (19) |
N2—Co1—N3i | 90.10 (7) | C4—N2—Co1 | 110.33 (14) |
N3—Co1—N3i | 180.00 (6) | C5—N2—Co1 | 143.64 (16) |
C2—C1—N1 | 109.4 (2) | N4—N3—Co1 | 119.70 (17) |
C2—C1—H1 | 125.3 | N5—N4—N3 | 179.0 (3) |
N1—C1—H1 | 125.3 | C4—N6—C6 | 108.01 (19) |
C1—C2—N7 | 105.91 (19) | C4—N6—H6A | 126.0 |
C1—C2—H2 | 127.0 | C6—N6—H6A | 126.0 |
N7—C2—H2 | 127.0 | C3—N7—C2 | 107.90 (18) |
N1—C3—N7 | 110.83 (19) | C3—N7—H7A | 126.0 |
N1—C3—C4 | 118.37 (18) | C2—N7—H7A | 126.1 |
N7—C3—C4 | 130.8 (2) |
Symmetry code: (i) −x+1/2, −y−1/2, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
N6—H6A···N5ii | 0.86 | 2.01 | 2.819 (3) | 156 |
N7—H7A···N5ii | 0.86 | 2.25 | 3.012 (3) | 148 |
N7—H7A···N3iii | 0.86 | 2.55 | 3.049 (3) | 118 |
Symmetry codes: (ii) −x+1/2, −y+1/2, −z+1; (iii) x−1/2, y+1/2, z. |
Experimental details
Crystal data | |
Chemical formula | [Co(N3)2(C6H6N4)2] |
Mr | 411.29 |
Crystal system, space group | Monoclinic, C2/c |
Temperature (K) | 293 |
a, b, c (Å) | 12.8085 (10), 8.7632 (5), 14.4793 (5) |
β (°) | 91.913 (1) |
V (Å3) | 1624.30 (17) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 1.09 |
Crystal size (mm) | 0.28 × 0.22 × 0.20 |
Data collection | |
Diffractometer | Bruker APEXII CCD |
Absorption correction | Multi-scan (SADABS; Bruker, 2001) |
Tmin, Tmax | 0.750, 0.811 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 1961, 1501, 1246 |
Rint | 0.022 |
(sin θ/λ)max (Å−1) | 0.606 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.029, 0.078, 1.00 |
No. of reflections | 1501 |
No. of parameters | 124 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.24, −0.21 |
Computer programs: APEX2 (Bruker, 2004), SAINT-Plus (Bruker, 2001), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL (Bruker, 2001).
D—H···A | D—H | H···A | D···A | D—H···A |
N6—H6A···N5i | 0.86 | 2.01 | 2.819 (3) | 156.1 |
N7—H7A···N5i | 0.86 | 2.25 | 3.012 (3) | 148.3 |
N7—H7A···N3ii | 0.86 | 2.55 | 3.049 (3) | 117.6 |
Symmetry codes: (i) −x+1/2, −y+1/2, −z+1; (ii) x−1/2, y+1/2, z. |
Acknowledgements
The authors are grateful for financial support from Henan University (grant No. 05YBGG013)
References
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Dworschak, R. T. & Plapp, B. V. (1977). Biochemistry, 16, 111–117. PubMed Web of Science Google Scholar
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The imidazole moiety is of biochemical importance due to its presence in more than 200 metalloenzymes, such as carboxypeptidase A (CPA), carbonic anhydrase (CA), liver alcohol dehydrogenase (LADH), and superoxide dismutase (SOD) (Rees et al., 1983; Hardman & Lipscomb, 1984; Kuo & Makinen, 1982; Dworschak & Plapp, 1977).
In the title compound, the CoII atom occupies an inversion centre, and is hexacoordinated by six N atoms from two chelating ligands of H2bim (2,2'-biimidizole; C6H6N4) and two azide ions, showing a slightly distorted octahedral geometry (Fig. 1). The four N atoms from the chelating H2bim consist of the base and the other two N atoms from two azide ions ocupy the axial positions. In the crystal, intermolecular N—H···N hydrogen bonds between 2,2'-biimidizole ligands and azide ions link the complexes into sheets lying in the (002) planes (Fig. 2).