Diaqua­bis(2,4-dioxo-1,2,3,4-tetra­hydro­pyrimidine-5-carboxyl­ato-κ²O,O′)cobalt(II)

The Co atom of the title compound, [Co(C₅H₃N₂O₄)₂(H₂O)₂], lies on a center of inversion and is chelated by the 2,4-dioxo-1,2,3,4-tetra­hydro­pyrimidine-5-carboxyl­ate anion through its 5-carboxyl­ate and 4-oxo donor atoms. The other two sites of the octa­hedron around the metal atom are occupied by water mol­ecules. The water mol­ecules and amino groups serve as donors to other acceptor sites, giving rise to a three-dimensional hydrogen-bonded network.

Key indicators

• Single-crystal X-ray study
• T = 295 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.030
• wR factor = 0.086
• Data-to-parameter ratio = 11.9

checkCIF/PLATON results

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PLAT152_ALERT_1_C Supplied and Calc Volume s.u. Inconsistent .....          ?
PLAT164_ALERT_4_C Nr. of Refined C-H H-Atoms in Heavy-At Struct...          1

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S1. Comment

2,4-Dihydroxypyridimine-5-carboxylic acid crystallizes as a monohydrate; the 2,4-dihydroxypyrimidinyl portion of the molecule exists a 2,4-dioxo-1,2,3,4-tetrahydropyrimidinyl entity having secondary nitrogen atoms and exocyclic carbon–oxygen double bonds (Law et al., 2004). The features are retained in the diaquamanganese(II) (Maistralis et al., 1991), dihydrated diaquairon(II) (Baran et al., 1996), triaquacobalt(II), triaquanickel(II) (Sun & Jin, 2004) and diaquacopper(II) (Luo et al., 2002) derivatives; the anion chelates to the metal atoms through the 5-carboxylato and 4-oxo oxygen atoms. The diaquamanganese (Maistralis et al., 1991), diaquacopper (Luo et al., 2002) and the present diaquacobalt(II) compounds are isostructural; two carboxylate monoanions chelate in this manner across a center of inversion. Hydrogen bonds link adjacent octahedral molecules into a three-dimensional network.

Related literature

For the crystal structure of 2,4-dihydroxypyridimine-5-carboxylic acid, see Law et al. (2004). For the crystal structures of other water-coordinated metal derivatives, see Maistralis et al. (1991) (Mn), Baran et al. (1996) (Fe), Sun & Jin (2004) (Fe and Co) and Luo et al. (2002) (Cu).

S2. Experimental

Cobalt(II) acetate hexahydrate (0.062 g, 0.25 mmol) and 2,4-dihydroxypyrimidine-5-carboxylic acid (0.087 g, 0.5 mmol) were placed in a 23-ml, Telefon-lined, stainless-steel Parr bomb together with water (6 ml) and THF (4 ml). The bomb was heated to 383 K for 144 h; it was then cooled over 48 h. Pink crystals were isolated in 70% yield.

S3. Refinement

All hydrogen atoms were located in a difference Fourier map, and were refined with distance restraints of C—H 0.95 (1) Å, N—H = O—H = 0.85 (1) Å. Their temperature factors were freely refined.

Computing details

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2007).

Figures

Fig. 1. Thermal ellipsoid plot of Co(C5H3N2O4)2(H2O)2. The molecule lies about a center-of-inversion, and the unlabeled atoms are related to the labeled ones by 1 - x, 1 - y, 1 - z.

Diaquabis(2,4-dioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylato- κ²O,O')cobalt(II)

Crystal data

[Co(C5H3N2O4)2(H2O)2]	F(000) = 410
Mr = 405.15	Dx = 1.923 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 1901 reflections
a = 5.0608 (6) Å	θ = 2.6–27.5°
b = 15.087 (2) Å	µ = 1.30 mm^−1
c = 9.290 (1) Å	T = 295 K
β = 99.389 (1)°	Block, pink
V = 699.8 (2) Å^3	0.20 × 0.20 × 0.10 mm
Z = 2

Data collection

Bruker APEXII area-detector diffractometer	1605 independent reflections
Radiation source: fine-focus sealed tube	1308 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.020
φ and ω scans	θmax = 27.5°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −6→6
Tmin = 0.743, Tmax = 0.881	k = −19→17
4291 measured reflections	l = −9→12

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.030	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.086	All H-atom parameters refined
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0481P)^2 + 0.1507P] where P = (Fo^2 + 2Fc^2)/3
1605 reflections	(Δ/σ)max = 0.001
135 parameters	Δρmax = 0.31 e Å^−3
5 restraints	Δρmin = −0.29 e Å^−3

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Co1	0.5000	0.5000	0.5000	0.02430 (14)
O1	0.2334 (3)	0.4047 (1)	0.4163 (2)	0.0289 (3)
O2	0.0616 (3)	0.2948 (1)	0.2730 (2)	0.0292 (3)
O3	0.6389 (3)	0.5050 (1)	0.3040 (2)	0.0267 (3)
O4	0.8892 (3)	0.4044 (1)	−0.1094 (2)	0.0314 (4)
O1W	0.7933 (3)	0.4003 (1)	0.5678 (2)	0.0322 (4)
N1	0.5619 (4)	0.3281 (1)	−0.0207 (2)	0.0264 (4)
N2	0.7483 (3)	0.4527 (1)	0.0975 (2)	0.0223 (4)
C1	0.2244 (4)	0.3567 (1)	0.3041 (2)	0.0218 (4)
C2	0.4114 (4)	0.3746 (1)	0.1976 (2)	0.0219 (4)
C3	0.4047 (4)	0.3190 (1)	0.0823 (2)	0.0257 (4)
C4	0.7430 (4)	0.3953 (1)	−0.0169 (2)	0.0240 (4)
C5	0.5999 (4)	0.4468 (1)	0.2087 (2)	0.0215 (4)
H11	0.930 (4)	0.403 (2)	0.527 (3)	0.07 (1)*
H12	0.842 (5)	0.394 (2)	0.659 (1)	0.05 (1)*
H1	0.557 (5)	0.288 (1)	−0.085 (2)	0.04 (1)*
H2	0.848 (5)	0.498 (1)	0.107 (3)	0.04 (1)*
H3	0.289 (4)	0.270 (1)	0.064 (2)	0.03 (1)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Co1	0.0236 (2)	0.0294 (2)	0.0220 (2)	−0.0043 (2)	0.0099 (2)	−0.0052 (2)
O1	0.0257 (7)	0.0373 (8)	0.0264 (8)	−0.0079 (6)	0.0118 (6)	−0.0074 (6)
O2	0.0324 (8)	0.0296 (8)	0.0266 (8)	−0.0086 (6)	0.0071 (6)	0.0023 (6)
O3	0.0303 (8)	0.0298 (8)	0.0223 (8)	−0.0066 (6)	0.0114 (6)	−0.0064 (6)
O4	0.0318 (8)	0.0403 (9)	0.0249 (8)	−0.0068 (6)	0.0130 (6)	−0.0051 (6)
O1W	0.0298 (9)	0.0377 (9)	0.0309 (9)	0.0008 (7)	0.0104 (7)	0.0001 (7)
N1	0.0294 (9)	0.0270 (9)	0.0245 (9)	−0.0028 (7)	0.0091 (7)	−0.0066 (7)
N2	0.0230 (9)	0.0247 (9)	0.0204 (8)	−0.0033 (7)	0.0075 (7)	−0.0015 (7)
C1	0.021 (1)	0.024 (1)	0.021 (1)	0.002 (1)	0.005 (1)	0.003 (1)
C2	0.022 (1)	0.023 (1)	0.022 (1)	0.000 (1)	0.006 (1)	0.000 (1)
C3	0.025 (1)	0.024 (1)	0.029 (1)	−0.002 (1)	0.008 (1)	−0.001 (1)
C4	0.022 (1)	0.028 (1)	0.022 (1)	0.001 (1)	0.006 (1)	0.000 (1)
C5	0.021 (1)	0.024 (1)	0.020 (1)	0.002 (1)	0.006 (1)	0.003 (1)

Geometric parameters (Å, º)

Co1—O1	2.037 (1)	N1—C4	1.364 (3)
Co1—O1^i	2.037 (1)	N2—C4	1.367 (2)
Co1—O3	2.058 (1)	N2—C5	1.376 (2)
Co1—O3^i	2.058 (1)	C1—C2	1.501 (3)
Co1—O1W	2.135 (2)	C2—C3	1.357 (3)
Co1—O1W^i	2.135 (2)	C2—C5	1.440 (3)
O1—C1	1.265 (2)	O1W—H11	0.85 (1)
O2—C1	1.247 (2)	O1W—H12	0.85 (1)
O3—C5	1.239 (2)	N1—H1	0.85 (1)
O4—C4	1.230 (2)	N2—H2	0.85 (1)
N1—C3	1.347 (3)	C3—H3	0.94 (1)
O1^i—Co1—O1	180.0	O1—C1—C2	119.9 (2)
O1^i—Co1—O3^i	89.33 (5)	C3—C2—C5	117.1 (2)
O1—Co1—O3^i	90.67 (5)	C3—C2—C1	118.1 (2)
O1^i—Co1—O3	90.67 (5)	C5—C2—C1	124.8 (2)
O1—Co1—O3	89.33 (5)	N1—C3—C2	123.8 (2)
O3^i—Co1—O3	180.0	O4—C4—N1	122.9 (2)
O1^i—Co1—O1W	89.97 (7)	O4—C4—N2	122.3 (2)
O1—Co1—O1W	90.03 (7)	N1—C4—N2	114.8 (2)
O3^i—Co1—O1W	92.00 (6)	O3—C5—N2	116.6 (2)
O3—Co1—O1W	88.00 (6)	O3—C5—C2	127.8 (2)
O1^i—Co1—O1W^i	90.03 (7)	N2—C5—C2	115.5 (2)
O1—Co1—O1W^i	89.97 (7)	Co1—O1W—H11	114 (2)
O3^i—Co1—O1W^i	88.00 (6)	Co1—O1W—H12	117 (2)
O3—Co1—O1W^i	92.00 (6)	H11—O1W—H12	109 (3)
O1W—Co1—O1W^i	180.0	C3—N1—H1	118 (2)
C1—O1—Co1	130.7 (1)	C4—N1—H1	120 (2)
C5—O3—Co1	124.7 (1)	C4—N2—H2	122 (2)
C3—N1—C4	122.0 (2)	C5—N2—H2	111 (2)
C4—N2—C5	126.8 (2)	N1—C3—H3	112.0 (13)
O2—C1—O1	123.6 (2)	C2—C3—H3	124.2 (13)
O2—C1—C2	116.5 (2)
O3^i—Co1—O1—C1	−164.2 (2)	C5—C2—C3—N1	−0.4 (3)
O3—Co1—O1—C1	15.8 (2)	C1—C2—C3—N1	179.9 (2)
O1W—Co1—O1—C1	−72.2 (2)	C3—N1—C4—O4	179.6 (2)
O1W^i—Co1—O1—C1	107.8 (2)	C3—N1—C4—N2	−1.0 (3)
O1^i—Co1—O3—C5	162.5 (2)	C5—N2—C4—O4	−177.8 (2)
O1—Co1—O3—C5	−17.5 (2)	C5—N2—C4—N1	2.8 (3)
O1W—Co1—O3—C5	72.5 (2)	Co1—O3—C5—N2	−168.1 (1)
O1W^i—Co1—O3—C5	−107.5 (2)	Co1—O3—C5—C2	13.9 (3)
Co1—O1—C1—O2	173.1 (1)	C4—N2—C5—O3	178.5 (2)
Co1—O1—C1—C2	−8.7 (3)	C4—N2—C5—C2	−3.2 (3)
O2—C1—C2—C3	−4.9 (3)	C3—C2—C5—O3	179.9 (2)
O1—C1—C2—C3	176.8 (2)	C1—C2—C5—O3	−0.4 (3)
O2—C1—C2—C5	175.4 (2)	C3—C2—C5—N2	1.8 (3)
O1—C1—C2—C5	−2.9 (3)	C1—C2—C5—N2	−178.5 (2)
C4—N1—C3—C2	−0.1 (3)

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H11···O1^ii	0.85 (1)	1.98 (1)	2.823 (2)	175 (3)
O1W—H12···O4^iii	0.85 (1)	2.14 (1)	2.959 (2)	165 (3)
N1—H1···O2^iv	0.85 (1)	1.81 (1)	2.667 (2)	177 (3)
N2—H2···O4^v	0.85 (1)	1.98 (1)	2.822 (2)	171 (3)

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