Diaqua­bis(2-oxidopyridinium-3-car­box­yl­ato-κ²O²,O³)cobalt(II)

In the title mononuclear complex, [Co(C₆H₄NO₃)₂(H₂O)₂], the six-coordinate Co^II atom assumes an octa­hedral geometry and is located on an inversion centre. There is a weak π–π stacking inter­action between adjacent pyridyl rings [centroid-to-centroid distance = 3.8067 (17) Å and perpendicular distance = 3.533 Å]. O—H...O, N—H...O and C—H...O hydrogen bonds connect the mononuclear complexes and form a supra­molecular three-dimensional structure.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.034
• wR factor = 0.083
• Data-to-parameter ratio = 12.6

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT710_ALERT_4_C Delete 1-2-3 or 2-3-4 Linear Torsion Angle ... #          3
            C6  -O1  -CO1 -O1      9.00 13.00   1.555   1.555   1.555   3.575
PLAT710_ALERT_4_C Delete 1-2-3 or 2-3-4 Linear Torsion Angle ... #         10
            O3  -CO1 -O3  -C2      2.00  0.00   3.575   1.555   1.555   1.555

Alert level G
PLAT794_ALERT_5_G Check Predicted Bond Valency for Co1         (2)       2.15

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   2 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Comment

Metal complexes containing N-heterocyclic ligands play a pivotal role in the area of modern coordination chemistry, and it has been reported that complex containing 3-hydroxypicolinamide ligand displays strong fluorescent emission (Sakai et al., 2006). The interest in this area led us to synthesize the title complex, and here we report its crystal structure, (I).

Fig. 1 shows the molecular structure of (I), the Co^II atom lies in an inversion centre and assumes a little distored octahedral geometry (Table 1). There is a weak π-π stacking interaction between adjacent pyridyl rings of the neighboring complexes; the relevant distances are Cg1···Cg1ⁱ = 3.8067 (17) Å and Cg1···Cg1ⁱ_perp = 3.533 Å [symmetry codes: (i) X, 3/2-Y, -1/2+Z; Cg1 is the centroid of pyridyl ring; Cg1···Cg1_perp is the perpendicular distance from ring Cg1 to ring Cg1ⁱ]. Table 2 and Fig. 2 show the information of O—H···O, N—H···O and C—H···O hydrogen bonds, and it is the hydrogen bonds that led to the connection of adjacent mononuclear complexes and to the formation of a super-molecular three-dimensional polymer.

Related literature

For a related crystal structure, see: Sakai et al. (2006).

S2. Experimental

Diluted sodium hydroxide H₂O solution was added in drops into 30 ml H₂O solution containing Co(ClO₄)₂.6H₂O (0.1830 g, 0.500 mmol) and 2-hydroxyl-3-carboxylpyridine (0.1390 g, 1.13 mmol) until the pH value reached 4, and the solution was stirred for another a few minutes. The red single crystals were obtained after the mixed solution had been allowed to stand at room temperature for one week.

S3. Refinement

H atoms of water molecule were located in a difference Fourier map and included in the refinements as riding in their as-found positions, with O—H = 0.886–0.889 Å, U_iso(H) = 1.5U_eq(O); the rest of the H atoms were placed in calculated positions with C—H = 0.93 Å, U_iso(H) = 1.2U_eq(C); N—H = 0.86 Å, U_iso(H) = 1.2U_eq(N).

Computing details

Data collection: SMART (Bruker, 1997); cell refinement: SAINT (Bruker, 1997); data reduction: SAINT; program(s) used to solve structure: SHELXS (Bruker, 2001); program(s) used to refine structure: SHELXTL (Bruker, 2001); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. The coordination structure of (I) showing the atom numbering scheme with thermal ellipsoids drawn at the 30% probability level. [Symmetry codes: (i) -x, -y + 2, -z].
	Fig. 2. Unit cell and hydrogen bonds (line of dashes).

Diaquabis(2-oxidopyridinium-3-carboxylate)cobalt(II)

Crystal data

[Co(C6H4NO3)2(H2O)2]	F(000) = 378
Mr = 371.17	Dx = 1.811 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1158 reflections
a = 7.4216 (19) Å	θ = 2.8–26.7°
b = 12.330 (3) Å	µ = 1.31 mm^−1
c = 7.550 (2) Å	T = 298 K
β = 99.921 (4)°	Prism, red
V = 680.6 (3) Å^3	0.26 × 0.20 × 0.05 mm
Z = 2

Data collection

Bruker SMART APEX CCD diffractometer	1331 independent reflections
Radiation source: fine-focus sealed tube	1151 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.035
φ and ω scans	θmax = 26.0°, θmin = 2.8°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −8→9
Tmin = 0.727, Tmax = 0.937	k = −15→8
3627 measured reflections	l = −9→8

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)] = 0.034	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.083	H-atom parameters constrained
S = 1.02	w = 1/[σ^2(Fo^2) + (0.0376P)^2 + 0.5342P] where P = (Fo^2 + 2Fc^2)/3
1331 reflections	(Δ/σ)max < 0.001
106 parameters	Δρmax = 0.39 e Å^−3
0 restraints	Δρmin = −0.30 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
O1	−0.0608 (2)	0.84059 (13)	−0.0153 (2)	0.0183 (4)
C6	0.0373 (3)	0.7569 (2)	0.0071 (3)	0.0153 (5)
Co1	0.0000	1.0000	0.0000	0.01392 (16)
O3	0.2707 (2)	0.95557 (14)	−0.0135 (2)	0.0185 (4)
N1	0.5220 (3)	0.86194 (17)	0.1087 (3)	0.0195 (5)
H1	0.5827	0.9211	0.1047	0.023*
O2	−0.0295 (2)	0.66277 (14)	−0.0126 (2)	0.0194 (4)
C1	0.2408 (3)	0.7664 (2)	0.0610 (3)	0.0158 (5)
C5	0.3400 (4)	0.6753 (2)	0.1223 (3)	0.0198 (6)
H4	0.2783	0.6098	0.1246	0.024*
O4	0.0769 (3)	0.99441 (13)	0.2817 (2)	0.0239 (4)
H6	0.0545	1.0547	0.3380	0.036*
H5	0.0372	0.9411	0.3444	0.036*
C2	0.3378 (3)	0.8659 (2)	0.0496 (3)	0.0157 (5)
C3	0.6169 (4)	0.7728 (2)	0.1729 (3)	0.0235 (6)
H2	0.7427	0.7769	0.2115	0.028*
C4	0.5282 (4)	0.6769 (2)	0.1809 (4)	0.0245 (6)
H3	0.5913	0.6145	0.2241	0.029*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0140 (9)	0.0112 (9)	0.0291 (10)	0.0005 (7)	0.0023 (7)	−0.0004 (7)
C6	0.0171 (13)	0.0169 (14)	0.0124 (11)	0.0000 (9)	0.0041 (10)	0.0001 (10)
Co1	0.0123 (3)	0.0098 (3)	0.0198 (3)	0.00027 (18)	0.00311 (18)	0.00043 (19)
O3	0.0146 (9)	0.0132 (9)	0.0285 (10)	0.0006 (7)	0.0055 (7)	0.0025 (8)
N1	0.0135 (11)	0.0200 (12)	0.0251 (12)	−0.0025 (8)	0.0031 (9)	0.0012 (9)
O2	0.0194 (10)	0.0111 (10)	0.0269 (10)	−0.0022 (7)	0.0020 (8)	−0.0005 (7)
C1	0.0171 (13)	0.0153 (13)	0.0152 (11)	−0.0011 (10)	0.0036 (10)	0.0005 (10)
C5	0.0203 (14)	0.0191 (14)	0.0209 (13)	−0.0001 (10)	0.0056 (11)	0.0030 (10)
O4	0.0371 (12)	0.0128 (9)	0.0223 (9)	−0.0003 (8)	0.0064 (8)	0.0011 (7)
C2	0.0138 (13)	0.0191 (14)	0.0148 (12)	−0.0004 (10)	0.0041 (10)	−0.0015 (10)
C3	0.0152 (13)	0.0317 (16)	0.0230 (13)	0.0024 (11)	0.0013 (11)	0.0075 (12)
C4	0.0207 (15)	0.0230 (15)	0.0294 (14)	0.0081 (11)	0.0033 (11)	0.0101 (11)

Geometric parameters (Å, º)

O1—C6	1.257 (3)	N1—C2	1.364 (3)
O1—Co1	2.0155 (17)	N1—H1	0.8600
C6—O2	1.261 (3)	C1—C5	1.379 (3)
C6—C1	1.500 (3)	C1—C2	1.432 (3)
Co1—O1^i	2.0155 (17)	C5—C4	1.390 (4)
Co1—O3^i	2.1016 (17)	C5—H4	0.9300
Co1—O3	2.1016 (17)	O4—H6	0.8862
Co1—O4^i	2.1065 (19)	O4—H5	0.8893
Co1—O4	2.1065 (19)	C3—C4	1.359 (4)
O3—C2	1.271 (3)	C3—H2	0.9300
N1—C3	1.350 (3)	C4—H3	0.9300
C6—O1—Co1	132.40 (16)	C3—N1—H1	117.3
O1—C6—O2	122.2 (2)	C2—N1—H1	117.3
O1—C6—C1	120.3 (2)	C5—C1—C2	118.3 (2)
O2—C6—C1	117.5 (2)	C5—C1—C6	118.8 (2)
O1^i—Co1—O1	180.0	C2—C1—C6	122.9 (2)
O1^i—Co1—O3^i	87.10 (7)	C1—C5—C4	123.0 (2)
O1—Co1—O3^i	92.90 (7)	C1—C5—H4	118.5
O1^i—Co1—O3	92.90 (7)	C4—C5—H4	118.5
O1—Co1—O3	87.10 (7)	Co1—O4—H6	114.6
O3^i—Co1—O3	180.0	Co1—O4—H5	120.3
O1^i—Co1—O4^i	92.57 (7)	H6—O4—H5	105.0
O1—Co1—O4^i	87.43 (7)	O3—C2—N1	117.4 (2)
O3^i—Co1—O4^i	86.87 (7)	O3—C2—C1	126.8 (2)
O3—Co1—O4^i	93.13 (7)	N1—C2—C1	115.8 (2)
O1^i—Co1—O4	87.43 (7)	N1—C3—C4	119.8 (2)
O1—Co1—O4	92.57 (7)	N1—C3—H2	120.1
O3^i—Co1—O4	93.13 (7)	C4—C3—H2	120.1
O3—Co1—O4	86.87 (7)	C3—C4—C5	117.8 (2)
O4^i—Co1—O4	180.00 (9)	C3—C4—H3	121.1
C2—O3—Co1	121.63 (15)	C5—C4—H3	121.1
C3—N1—C2	125.3 (2)
Co1—O1—C6—O2	−178.61 (15)	O2—C6—C1—C2	165.8 (2)
Co1—O1—C6—C1	2.1 (3)	C2—C1—C5—C4	3.0 (4)
C6—O1—Co1—O1^i	9 (13)	C6—C1—C5—C4	−177.8 (2)
C6—O1—Co1—O3^i	−164.1 (2)	Co1—O3—C2—N1	−151.59 (17)
C6—O1—Co1—O3	15.9 (2)	Co1—O3—C2—C1	30.4 (3)
C6—O1—Co1—O4^i	109.2 (2)	C3—N1—C2—O3	−177.3 (2)
C6—O1—Co1—O4	−70.8 (2)	C3—N1—C2—C1	1.0 (4)
O1^i—Co1—O3—C2	149.27 (18)	C5—C1—C2—O3	175.4 (2)
O1—Co1—O3—C2	−30.73 (18)	C6—C1—C2—O3	−3.8 (4)
O3^i—Co1—O3—C2	−15 (93)	C5—C1—C2—N1	−2.6 (3)
O4^i—Co1—O3—C2	−117.99 (18)	C6—C1—C2—N1	178.2 (2)
O4—Co1—O3—C2	62.01 (18)	C2—N1—C3—C4	0.5 (4)
O1—C6—C1—C5	166.0 (2)	N1—C3—C4—C5	−0.3 (4)
O2—C6—C1—C5	−13.3 (3)	C1—C5—C4—C3	−1.4 (4)
O1—C6—C1—C2	−14.8 (3)

Symmetry code: (i) −x, −y+2, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O4—H5···O2^ii	0.89	1.80	2.686 (2)	175
O4—H6···O2^iii	0.89	1.91	2.772 (2)	165
N1—H1···O3^iv	0.86	2.06	2.886 (3)	162
C3—H2···O1^v	0.93	2.56	3.100 (3)	118
C3—H2···O2^vi	0.93	2.56	3.318 (3)	139

Symmetry codes: (ii) x, −y+3/2, z+1/2; (iii) −x, y+1/2, −z+1/2; (iv) −x+1, −y+2, −z; (v) x+1, y, z; (vi) x+1, −y+3/2, z+1/2.