Tetra­aqua­bis­[2-(2-nitro­phen­yl)acetato-κO]cobalt(II)

Abstract

The mol­ecule of the title compound, [Co(C₈H₆NO₄)₂(H₂O)₄], is centrosymmetric. It is a cobalt(II) complex, bearing two (2-nitro­phen­yl)acetate and four aqua ligands. The coordination around the Co^II atom is distorted octa­hedral, defined by four O atoms of water mol­ecules in the equatorial plane and by two carboxyl­ate O atoms at axial positions. The dihedral angles between the benzene ring and the acetate and nitro groups are 61.90 (10) and 19.21 (11)°, respectively. The water mol­ecules form O—H⋯O hydrogen bonds with the nitro and carboxyl­ate groups, leading to a layered structural arrangement parallel to (001).

Related literature  

The title compound is structurally related to tetra­aqua­bis(acetato-κO)cobalt(II) (Sobolev et al., 2003 ▸), tetra­aqua­bis­(2-nitro­phen­oxy­ethano­ato-κO)cobalt(II) dihydrate (Kennard et al., 1985 ▸), tetra­aqua­bis­((2,4-di­chloro­phen­oxy)acetato-κO)cobalt(II) dihydrate (Tan et al., 2011 ▸), tetra­aqua­bis­[2-(6-amino-9H-purin-9-yl)acetato-κO]cobalt(II) (Mishra et al., 2011 ▸) and tetra­aqua­bis­(3,5-di­nitro­benzoato-κO)cobalt(II) tetra­hydrate (Tahir et al., 1996 ▸).

Experimental  

Crystal data  

• [Co(C₈H₆NO₄)₂(H₂O)₄]

• M _r = 491.27

• Monoclinic,

• a = 5.4431 (3) Å

• b = 6.4313 (4) Å

• c = 28.5697 (15) Å

• β = 92.762 (2)°

• V = 998.96 (10) ų

• Z = 2

• Mo Kα radiation

• μ = 0.93 mm⁻¹

• T = 296 K

• 0.32 × 0.24 × 0.20 mm

Data collection  

• Bruker Kappa APEXII CCD diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2007 ▸) T _min = 0.758, T _max = 0.835

• 8913 measured reflections

• 2156 independent reflections

• 1937 reflections with I > 2σ(I)

• R _int = 0.026

Refinement  

• R[F ² > 2σ(F ²)] = 0.028

• wR(F ²) = 0.070

• S = 1.04

• 2156 reflections

• 154 parameters

• H atoms treated by a mixture of independent and constrained refinement

• Δρ_max = 0.27 e Å⁻³

• Δρ_min = −0.28 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▸); cell refinement: SAINT (Bruker, 2007 ▸); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▸); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▸); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▸) and PLATON (Spek, 2009 ▸); software used to prepare material for publication: WinGX (Farrugia, 2012 ▸) and PLATON.

Supplementary Material

CCDC reference: 1047494

Additional supporting information: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (, ).

DHA	DH	HA	D A	DHA
O5H5AO1i	0.82(2)	2.00(2)	2.7984(16)	166(2)
O5H5BO2ii	0.82(2)	1.89(2)	2.6797(17)	161(2)
O6H6AO2iii	0.78(2)	1.93(2)	2.6979(17)	169(2)
O6H6BO3	0.81(2)	2.22(2)	2.988(2)	159(2)

Symmetry codes: (i) ; (ii) ; (iii) .

supplementary crystallographic information

S1. Experimental

The sodium salt of (2-nitrophenyl)acetic acid was prepared by mixing aqueous solutions of (2-nitrophenyl)acetic acid and Na(HCO₃) in the molar ratio 1:1. To this solution a 0.5 molar equivalent of cobalt(II) acetate was added and the mixture refluxed for 4 h. The resulting solution was evaporated for crystal growth. Light-orange prisms suitable for X-ray data collection were obtained after one week.

S2. Refinement

The coordinates of water H-atoms were refined freely, with U_iso(H) = 1.2U_eq(O). The other H-atoms were positioned geometrically (C—H = 0.93—0.97 Å) and refined as riding with U_iso(H) = 1.2U_eq(C).

Figures

Fig. 1.

View of the asymmetric unit of title compound with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. H-atoms are shown as small circles of arbitrary radius.

Fig. 2.

A partial packing diagram of the title compound showing the layered organisation of molecules held together by O—H···O interactions (dashed lines). H atoms not involved in hydrogen bonding are omitted for clarity.

Crystal data

[Co(C8H6NO4)2(H2O)4]	F(000) = 506
Mr = 491.27	Dx = 1.633 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 5.4431 (3) Å	Cell parameters from 2154 reflections
b = 6.4313 (4) Å	θ = 2.9–27.0°
c = 28.5697 (15) Å	µ = 0.93 mm−1
β = 92.762 (2)°	T = 296 K
V = 998.96 (10) Å3	Prism, light-orange
Z = 2	0.32 × 0.24 × 0.20 mm

Data collection

Bruker Kappa APEXII CCD diffractometer	2156 independent reflections
Radiation source: fine-focus sealed tube	1937 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.026
Detector resolution: 7.80 pixels mm-1	θmax = 27.0°, θmin = 2.9°
ω scans	h = −6→5
Absorption correction: multi-scan (SADABS; Bruker, 2007)	k = −8→8
Tmin = 0.758, Tmax = 0.835	l = −36→36
8913 measured reflections

Refinement

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)] = 0.028	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.070	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	w = 1/[σ2(Fo2) + (0.0339P)2 + 0.3677P] where P = (Fo2 + 2Fc2)/3
2156 reflections	(Δ/σ)max < 0.001
154 parameters	Δρmax = 0.27 e Å−3
0 restraints	Δρmin = −0.28 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
Co1	1.0000	0.0000	0.0000	0.02745 (10)
O1	0.78213 (19)	0.21130 (18)	0.03439 (4)	0.0354 (3)
O2	1.0428 (2)	0.45515 (17)	0.06128 (4)	0.0349 (3)
O3	0.9861 (3)	0.1663 (2)	0.13936 (6)	0.0656 (4)
O4	1.2715 (3)	0.2897 (3)	0.18485 (7)	0.0860 (6)
O5	0.7121 (2)	−0.21593 (19)	−0.00252 (5)	0.0367 (3)
H5A	0.572 (4)	−0.193 (3)	−0.0126 (7)	0.044*
H5B	0.761 (4)	−0.309 (3)	−0.0197 (7)	0.044*
O6	1.1243 (2)	−0.1312 (2)	0.06473 (5)	0.0396 (3)
H6A	1.089 (4)	−0.249 (4)	0.0668 (7)	0.047*
H6B	1.076 (4)	−0.079 (4)	0.0883 (8)	0.047*
N1	1.0723 (3)	0.3042 (2)	0.16413 (5)	0.0449 (4)
C1	0.8429 (3)	0.3604 (2)	0.06134 (5)	0.0302 (3)
C2	0.6512 (3)	0.4255 (4)	0.09495 (7)	0.0465 (5)
H2A	0.5280	0.5076	0.0776	0.056*
H2B	0.5702	0.3010	0.1056	0.056*
C3	0.7378 (3)	0.5481 (3)	0.13750 (6)	0.0360 (4)
C4	0.6146 (4)	0.7320 (3)	0.14716 (7)	0.0477 (5)
H4	0.4881	0.7762	0.1265	0.057*
C5	0.6733 (4)	0.8505 (3)	0.18614 (7)	0.0501 (5)
H5	0.5823	0.9693	0.1920	0.060*
C6	0.8658 (4)	0.7945 (3)	0.21649 (7)	0.0478 (5)
H6	0.9062	0.8753	0.2427	0.057*
C7	0.9977 (3)	0.6180 (3)	0.20765 (6)	0.0419 (4)
H7	1.1312	0.5804	0.2274	0.050*
C8	0.9304 (3)	0.4964 (2)	0.16911 (6)	0.0340 (4)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Co1	0.01995 (16)	0.02718 (16)	0.03467 (18)	0.00213 (11)	−0.00444 (11)	−0.00896 (12)
O1	0.0242 (5)	0.0371 (6)	0.0445 (7)	0.0033 (5)	−0.0030 (5)	−0.0170 (5)
O2	0.0296 (6)	0.0312 (6)	0.0437 (7)	0.0001 (5)	−0.0005 (5)	−0.0103 (5)
O3	0.0995 (13)	0.0358 (8)	0.0613 (9)	0.0115 (8)	0.0019 (9)	−0.0049 (7)
O4	0.0700 (11)	0.0865 (13)	0.0987 (14)	0.0409 (10)	−0.0245 (10)	−0.0129 (11)
O5	0.0227 (6)	0.0368 (6)	0.0501 (7)	0.0005 (5)	−0.0034 (5)	−0.0142 (6)
O6	0.0452 (7)	0.0307 (6)	0.0417 (7)	0.0038 (5)	−0.0094 (6)	−0.0072 (5)
N1	0.0545 (10)	0.0427 (9)	0.0380 (8)	0.0124 (7)	0.0064 (7)	0.0062 (7)
C1	0.0244 (8)	0.0328 (8)	0.0328 (8)	0.0075 (6)	−0.0058 (6)	−0.0059 (6)
C2	0.0287 (9)	0.0635 (12)	0.0468 (11)	0.0016 (8)	−0.0009 (8)	−0.0240 (9)
C3	0.0286 (9)	0.0451 (9)	0.0345 (9)	0.0011 (7)	0.0027 (7)	−0.0089 (7)
C4	0.0394 (10)	0.0592 (12)	0.0439 (10)	0.0161 (9)	−0.0047 (8)	−0.0120 (9)
C5	0.0569 (12)	0.0461 (11)	0.0473 (11)	0.0134 (9)	0.0030 (9)	−0.0123 (9)
C6	0.0560 (12)	0.0498 (11)	0.0374 (10)	0.0006 (9)	0.0010 (8)	−0.0146 (8)
C7	0.0417 (10)	0.0530 (11)	0.0305 (8)	0.0021 (8)	−0.0034 (7)	−0.0011 (8)
C8	0.0351 (9)	0.0353 (9)	0.0319 (8)	0.0026 (7)	0.0054 (7)	0.0003 (7)

Geometric parameters (Å, º)

Co1—O1i	2.0810 (11)	C1—C2	1.511 (2)
Co1—O1	2.0810 (11)	C2—C3	1.505 (2)
Co1—O5	2.0925 (12)	C2—H2A	0.9700
Co1—O5i	2.0925 (12)	C2—H2B	0.9700
Co1—O6	2.1141 (13)	C3—C8	1.391 (2)
Co1—O6i	2.1141 (13)	C3—C4	1.394 (3)
O1—C1	1.2637 (18)	C4—C5	1.374 (3)
O2—C1	1.2473 (19)	C4—H4	0.9300
O3—N1	1.214 (2)	C5—C6	1.376 (3)
O4—N1	1.213 (2)	C5—H5	0.9300
O5—H5A	0.82 (2)	C6—C7	1.373 (3)
O5—H5B	0.82 (2)	C6—H6	0.9300
O6—H6A	0.78 (2)	C7—C8	1.385 (2)
O6—H6B	0.81 (2)	C7—H7	0.9300
N1—C8	1.468 (2)
O1i—Co1—O1	180.0	O2—C1—C2	119.65 (14)
O1i—Co1—O5	89.61 (5)	O1—C1—C2	115.40 (14)
O1—Co1—O5	90.39 (5)	C3—C2—C1	117.33 (14)
O1i—Co1—O5i	90.39 (5)	C3—C2—H2A	108.0
O1—Co1—O5i	89.61 (5)	C1—C2—H2A	108.0
O5—Co1—O5i	180.0	C3—C2—H2B	108.0
O1i—Co1—O6	89.23 (5)	C1—C2—H2B	108.0
O1—Co1—O6	90.77 (5)	H2A—C2—H2B	107.2
O5—Co1—O6	88.44 (5)	C8—C3—C4	115.41 (16)
O5i—Co1—O6	91.56 (5)	C8—C3—C2	126.60 (16)
O1i—Co1—O6i	90.77 (5)	C4—C3—C2	117.98 (16)
O1—Co1—O6i	89.23 (5)	C5—C4—C3	122.40 (18)
O5—Co1—O6i	91.56 (5)	C5—C4—H4	118.8
O5i—Co1—O6i	88.44 (5)	C3—C4—H4	118.8
O6—Co1—O6i	180.00 (6)	C4—C5—C6	120.38 (18)
C1—O1—Co1	130.14 (10)	C4—C5—H5	119.8
Co1—O5—H5A	125.5 (15)	C6—C5—H5	119.8
Co1—O5—H5B	103.7 (14)	C7—C6—C5	119.33 (17)
H5A—O5—H5B	104 (2)	C7—C6—H6	120.3
Co1—O6—H6A	112.4 (16)	C5—C6—H6	120.3
Co1—O6—H6B	117.5 (16)	C6—C7—C8	119.51 (17)
H6A—O6—H6B	104 (2)	C6—C7—H7	120.2
O4—N1—O3	122.64 (18)	C8—C7—H7	120.2
O4—N1—C8	118.61 (17)	C7—C8—C3	122.90 (16)
O3—N1—C8	118.75 (16)	C7—C8—N1	115.63 (16)
O2—C1—O1	124.94 (15)	C3—C8—N1	121.46 (15)
Co1—O1—C1—O2	25.0 (2)	C6—C7—C8—C3	2.2 (3)
Co1—O1—C1—C2	−156.08 (13)	C6—C7—C8—N1	−176.35 (17)
O2—C1—C2—C3	−20.9 (3)	C4—C3—C8—C7	−0.1 (3)
O1—C1—C2—C3	160.19 (17)	C2—C3—C8—C7	−179.68 (18)
C1—C2—C3—C8	−50.9 (3)	C4—C3—C8—N1	178.29 (16)
C1—C2—C3—C4	129.5 (2)	C2—C3—C8—N1	−1.3 (3)
C8—C3—C4—C5	−2.3 (3)	O4—N1—C8—C7	−19.3 (3)
C2—C3—C4—C5	177.3 (2)	O3—N1—C8—C7	160.92 (17)
C3—C4—C5—C6	2.6 (3)	O4—N1—C8—C3	162.21 (19)
C4—C5—C6—C7	−0.5 (3)	O3—N1—C8—C3	−17.6 (3)
C5—C6—C7—C8	−1.8 (3)

Symmetry code: (i) −x+2, −y, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O5—H5A···O1ii	0.82 (2)	2.00 (2)	2.7984 (16)	166 (2)
O5—H5B···O2i	0.82 (2)	1.89 (2)	2.6797 (17)	161 (2)
O6—H6A···O2iii	0.78 (2)	1.93 (2)	2.6979 (17)	169 (2)
O6—H6B···O3	0.81 (2)	2.22 (2)	2.988 (2)	159 (2)

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