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Acta Cryst. (2008). E64, m289    [ doi:10.1107/S1600536807067815 ]

A redetermination of bis(5,5'-diethylbarbiturato)bis(imidazole)cobalt(II)

R.-Z. Fan, P.-Z. Hong and W.-D. Song

Abstract top

The title complex, [Co(C8H12N2O3)2(C3H4N2)2], whose structure was first determined by Wang & Craven [(1971). J. Chem. Soc. D, pp. 290-291], has been redetermined with improved precision. A crystallographic twofold rotation axis passes through the Co atom, which is tetrahedrally coordinated by two N atoms from two barbital ligands and two N atoms from two imidazole ligands. The molecules are self-assembled via intermolecular N-H...O hydrogen-bonding interactions into a supramolecular network.

Comment top

In the present paper we report the redetermination of the crystal structure of the title complex using CCD data at room temperature. The structure agrees with the results reported previously by Wang & Craven (1971; CCDC refcode BARICO) with lattice parameters a = 13.362 (2) Å, b = 10.133 (2) Å, c = 20.544 (4) Å β = 100.33 (3) °), but with improved precision.

As illustrated in Figure 1, the cobalt(II) atom, possesses a crystallogarphically imposed C2 symmetry, and displays a tetrahedral coordination geometry provided by two N atoms from two barbital ligands and two N atoms from two imidazole ligands. Intermolecular N—H···O hydrogen bonding interactions (Table 1) govern the crystal packing (Fig. 2).

Related literature top

For related literature, see: Wang & Craven (1971).

Experimental top

A mixture of cobalt nitrate (1 mmol), imidazole (1 mmol), barbital (1 mmol), NaOH (1.5 mmol) and H2O (12 ml) was placed in a 23 ml Teflon reactor, which was heated to 433 K for three days and then cooled to room temperature at a rate of 10 K h-1. The crystals obtained were washed with water and dryed in air.

Refinement top

All H atoms were placed at calculated positions and treated as riding on the parent atoms with C—H = 0.93–0.97 Å; N—H = 0.86 Å, and with Uiso(H) = 1.2 Ueq(C, N) or 1.5 Ueq(C) for methyl H atoms.

Computing details top

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL (Bruker, 2004); software used to prepare material for publication: SHELXTL (Bruker, 2004).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, showing the atom numbering scheme and 30% probability displacement ellipsoids. Unlabelled atoms are related to the labelled atoms by the symmetry operator (-x, y, 0.5 - z).
[Figure 2] Fig. 2. Packing diagram of the title compound viewed along the b axis. Intermolecluar hydrogen bonds are shown as dashed lines.
bis(5,5'-diethylbarbiturato)bis(imidazole)cobalt(II) top
Crystal data top
[Co(C8H12N2O3)2(C3H4N2)2]F000 = 1172
Mr = 561.47Dx = 1.359 Mg m−3
Monoclinic, C2/cMo Kα radiation
λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 3600 reflections
a = 13.3750 (3) Åθ = 1.4–28º
b = 10.1371 (2) ŵ = 0.68 mm−1
c = 20.5791 (4) ÅT = 296 (2) K
β = 100.4090 (10)ºBlock, pink
V = 2744.27 (10) Å30.32 × 0.26 × 0.25 mm
Z = 4
Data collection top
Bruker APEXII area-detector
diffractometer		3141 independent reflections
Radiation source: fine-focus sealed tube2596 reflections with I > 2σ(I)
Monochromator: graphiteRint = 0.029
T = 296(2) Kθmax = 27.5º
φ and ω scansθmin = 2.0º
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)		h = −17→16
Tmin = 0.813, Tmax = 0.849k = −12→13
18228 measured reflectionsl = −26→26
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.032H-atom parameters constrained
wR(F2) = 0.079  w = 1/[σ2(Fo2) + (0.0343P)2 + 2.0613P]
where P = (Fo2 + 2Fc2)/3
S = 0.98(Δ/σ)max < 0.001
3141 reflectionsΔρmax = 0.21 e Å−3
170 parametersΔρmin = −0.28 e Å−3
Primary atom site location: structure-invariant direct methodsExtinction correction: none
Crystal data top
[Co(C8H12N2O3)2(C3H4N2)2]V = 2744.27 (10) Å3
Mr = 561.47Z = 4
Monoclinic, C2/cMo Kα
a = 13.3750 (3) ŵ = 0.68 mm−1
b = 10.1371 (2) ÅT = 296 (2) K
c = 20.5791 (4) Å0.32 × 0.26 × 0.25 mm
β = 100.4090 (10)º
Data collection top
Bruker APEXII area-detector
diffractometer		3141 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)		2596 reflections with I > 2σ(I)
Tmin = 0.813, Tmax = 0.849Rint = 0.029
18228 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.032170 parameters
wR(F2) = 0.079H-atom parameters constrained
S = 0.98Δρmax = 0.21 e Å−3
3141 reflectionsΔρmin = −0.28 e Å−3
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
xyzUiso*/Ueq
C10.07766 (14)−0.1841 (2)0.16104 (9)0.0574 (5)
H10.0212−0.16840.12840.069*
C20.14986 (15)−0.2732 (2)0.15704 (9)0.0579 (5)
H20.1533−0.33030.12210.069*
C30.18454 (13)−0.17053 (19)0.25137 (8)0.0524 (4)
H30.2178−0.14570.29320.063*
C4−0.01891 (13)0.20721 (19)0.34360 (8)0.0502 (4)
C50.00221 (14)0.3032 (2)0.40182 (9)0.0581 (5)
C60.10237 (14)0.27581 (19)0.44751 (8)0.0535 (5)
C70.13212 (12)0.08668 (17)0.37956 (7)0.0418 (4)
C80.0058 (2)0.4435 (2)0.37466 (12)0.0845 (8)
H8A−0.05830.46150.34560.101*
H8B0.01210.50500.41130.101*
C90.0911 (3)0.4694 (3)0.33716 (17)0.1117 (11)
H9A0.15530.45840.36630.168*
H9B0.08580.55800.32030.168*
H9C0.08650.40840.30110.168*
C10−0.08480 (17)0.2920 (3)0.44236 (11)0.0849 (8)
H10A−0.07110.35330.47910.102*
H10B−0.14790.31900.41450.102*
C11−0.0995 (2)0.1564 (4)0.46924 (16)0.1166 (11)
H11A−0.11800.09580.43330.175*
H11B−0.15260.15940.49500.175*
H11C−0.03740.12790.49660.175*
Co10.00000.00895 (3)0.25000.03642 (10)
N10.09912 (10)−0.11875 (14)0.22073 (6)0.0452 (3)
N20.21731 (12)−0.26297 (17)0.21478 (8)0.0589 (4)
H2A0.2719−0.30870.22570.071*
N30.04631 (10)0.11057 (14)0.33481 (6)0.0408 (3)
N40.15545 (11)0.16886 (15)0.43447 (6)0.0497 (4)
H40.20890.14950.46280.060*
O10.19031 (11)−0.00247 (13)0.37358 (7)0.0620 (4)
O2−0.09826 (10)0.21962 (16)0.30314 (6)0.0724 (4)
O30.13421 (11)0.34732 (15)0.49451 (7)0.0751 (5)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0473 (10)0.0736 (13)0.0437 (9)0.0084 (10)−0.0125 (8)−0.0131 (9)
C20.0524 (11)0.0659 (12)0.0504 (10)0.0040 (10)−0.0038 (8)−0.0171 (9)
C30.0449 (10)0.0648 (12)0.0412 (9)0.0095 (9)−0.0089 (7)−0.0080 (8)
C40.0446 (10)0.0619 (11)0.0368 (8)0.0068 (9)−0.0122 (7)−0.0087 (8)
C50.0504 (11)0.0683 (12)0.0452 (9)0.0222 (9)−0.0187 (8)−0.0180 (9)
C60.0497 (10)0.0634 (12)0.0394 (8)0.0134 (9)−0.0132 (7)−0.0120 (8)
C70.0401 (9)0.0465 (9)0.0343 (7)−0.0006 (8)−0.0052 (6)−0.0031 (7)
C80.0978 (19)0.0642 (14)0.0731 (14)0.0269 (14)−0.0336 (14)−0.0164 (12)
C90.141 (3)0.0743 (18)0.105 (2)−0.0077 (18)−0.018 (2)0.0143 (16)
C100.0596 (14)0.127 (2)0.0608 (13)0.0337 (15)−0.0081 (11)−0.0310 (14)
C110.096 (2)0.168 (4)0.090 (2)0.012 (2)0.0298 (17)0.004 (2)
Co10.03201 (16)0.04302 (19)0.02885 (14)0.000−0.00886 (11)0.000
N10.0395 (8)0.0538 (9)0.0371 (7)0.0054 (6)−0.0067 (6)−0.0036 (6)
N20.0468 (9)0.0704 (11)0.0539 (9)0.0185 (8)−0.0056 (7)−0.0098 (8)
N30.0375 (7)0.0476 (8)0.0319 (6)0.0007 (6)−0.0080 (5)−0.0059 (5)
N40.0439 (8)0.0590 (9)0.0370 (7)0.0130 (7)−0.0174 (6)−0.0115 (6)
O10.0582 (8)0.0623 (9)0.0564 (7)0.0201 (7)−0.0142 (6)−0.0180 (6)
O20.0549 (8)0.0944 (11)0.0536 (8)0.0226 (8)−0.0281 (6)−0.0210 (7)
O30.0684 (9)0.0848 (10)0.0570 (8)0.0268 (8)−0.0291 (7)−0.0361 (7)
Geometric parameters (Å, °) top
C1—C21.336 (3)C8—C91.512 (4)
C1—N11.379 (2)C8—H8A0.9700
C1—H10.9300C8—H8B0.9700
C2—N21.360 (2)C9—H9A0.9600
C2—H20.9300C9—H9B0.9600
C3—N11.311 (2)C9—H9C0.9600
C3—N21.325 (2)C10—C111.507 (4)
C3—H30.9300C10—H10A0.9700
C4—O21.231 (2)C10—H10B0.9700
C4—N31.346 (2)C11—H11A0.9600
C4—C51.529 (2)C11—H11B0.9600
C5—C61.517 (2)C11—H11C0.9600
C5—C81.532 (3)Co1—N1i2.0210 (14)
C5—C101.554 (3)Co1—N12.0210 (14)
C6—O31.222 (2)Co1—N32.0249 (12)
C6—N41.349 (2)Co1—N3i2.0249 (12)
C7—O11.213 (2)N2—H2A0.8600
C7—N31.3571 (19)N4—H40.8600
C7—N41.393 (2)
C2—C1—N1110.08 (15)C8—C9—H9C109.5
C2—C1—H1125.0H9A—C9—H9C109.5
N1—C1—H1125.0H9B—C9—H9C109.5
C1—C2—N2105.50 (16)C11—C10—C5115.1 (2)
C1—C2—H2127.3C11—C10—H10A108.5
N2—C2—H2127.3C5—C10—H10A108.5
N1—C3—N2111.02 (15)C11—C10—H10B108.5
N1—C3—H3124.5C5—C10—H10B108.5
N2—C3—H3124.5H10A—C10—H10B107.5
O2—C4—N3118.95 (15)C10—C11—H11A109.5
O2—C4—C5118.64 (16)C10—C11—H11B109.5
N3—C4—C5122.41 (14)H11A—C11—H11B109.5
C6—C5—C8108.28 (18)C10—C11—H11C109.5
C6—C5—C4112.75 (15)H11A—C11—H11C109.5
C8—C5—C4108.56 (16)H11B—C11—H11C109.5
C6—C5—C10108.49 (16)N1i—Co1—N1100.33 (9)
C8—C5—C10109.85 (19)N1i—Co1—N3100.60 (5)
C4—C5—C10108.90 (17)N1—Co1—N3117.89 (5)
O3—C6—N4120.88 (15)N1i—Co1—N3i117.89 (5)
O3—C6—C5121.64 (16)N1—Co1—N3i100.60 (5)
N4—C6—C5117.47 (14)N3—Co1—N3i118.85 (8)
O1—C7—N3122.91 (14)C3—N1—C1105.02 (15)
O1—C7—N4118.29 (14)C3—N1—Co1132.44 (12)
N3—C7—N4118.80 (15)C1—N1—Co1122.06 (11)
C9—C8—C5115.1 (2)C3—N2—C2108.38 (15)
C9—C8—H8A108.5C3—N2—H2A125.8
C5—C8—H8A108.5C2—N2—H2A125.8
C9—C8—H8B108.5C4—N3—C7121.87 (13)
C5—C8—H8B108.5C4—N3—Co1112.43 (10)
H8A—C8—H8B107.5C7—N3—Co1125.70 (11)
C8—C9—H9A109.5C6—N4—C7126.37 (14)
C8—C9—H9B109.5C6—N4—H4116.8
H9A—C9—H9B109.5C7—N4—H4116.8
Symmetry codes: (i) −x, y, −z+1/2.
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
N2—H2A···O2ii0.862.152.7932 (19)131
N4—H4···O3iii0.862.122.9312 (18)156
Symmetry codes: (ii) x+1/2, y−1/2, z; (iii) −x+1/2, −y+1/2, −z+1.
Table 1
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
N2—H2A···O2i0.862.152.7932 (19)131
N4—H4···O3ii0.862.122.9312 (18)156
Symmetry codes: (i) x+1/2, y−1/2, z; (ii) −x+1/2, −y+1/2, −z+1.
Acknowledgements top

The authors acknowledge Guang Dong Ocean University for supporting this work.

references
References top

Bruker (2004). APEX2 (Version 7.23A), SAINT (Version 7.23A) and SHELXTL (Version 6.12). Bruker AXS Inc., Madison, Wisconsin, USA.

Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.

Sheldrick, G. M. (1997). SHELXL97 and SHELXS97. University of Göttingen, Germany.

Wang, B. C. & Craven, B. M. (1971). J. Chem. Soc. D, pp. 290–291.