Hexa­aqua­cobalt(II) bis(4-hydroxy­isophthalate) tetrahydrate

Hydro­thermal reaction of 4-hydroxy­isophthalic acid and Co(NO₃)₂·6H₂O in water resulted in a new mononuclear cobalt compound, [Co(H₂O)₆](C₈H₅O₅)₂·4H₂O. The occurrence of an intricate hydrogen-bond network leads to the formation of a three-dimensional structure. The cation lies on a crystallographic inversion center, while the anion and water molecules are in general positions.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.035
• wR factor = 0.095
• Data-to-parameter ratio = 10.2

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

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S1. Comment

The design and synthesis of new compounds with structures defined through non-covalent connections is currently of great interest because of their potential application in some areas, such as gas storage (Atwood et al., 1999), catalysis (Thomas,1998), molecular transport (Gardner et al., 1995) and biosynthesis (Lippert, 1997). As is already known in the fields of supramolecular chemistry and crystal engineering, hydrogen bonding plays an important role. Many examples of compounds that assemble by hydrogen-bonding interactions have been reported in previous works (Yuan et al., 2002). The great structural diversity of crystal packing results not only from the variability of the organic ligands and the ligand-to-metal connections, but also from the types and fashions of hydrogen bonding and other weak intermolecular interactions (Naumann et al., 2002). Although, 4-hydroxyisophthalic acid, which possesses four carboxylic oxygen atoms and one hydroxyl oxygen atom, is a good candidate to generate rich linking modes, including hydrogen bonding, it has been rarely reported in recent years. Herein we report the preparation and characterization of the first 4-hydroxyisophthalate–cobalt(II) complex, [Co(C₈H₅O₅)₂(H₂O)₆]·4H₂O, (I).

An X-ray analysis reveals that the (I) possesses a mononuclear structure. A view of the cobalt ion coordination is shown in Fig. 1, where the metal center is coordinated in an octahedral geometry by six water molecules with Co—O distances ranging from 2.0386 (18) to 2.1371 (18) Å. The 4-hydroxyisophthalate ligand in which only one carboxylic acid group is deprotoned, is not directly coordinated to the cobalt ion but is involved in a hydrogen-bond interaction with it. Different types of hydrogen-bonding interactions are observed (Table 2) in which O atoms may act as donors or acceptors: (a) hydrogen bonds between coordinated water and isolated water molecules, with O···O distances ranging from 2.627 (3) to 2.982 (3) Å; (b) hydrogen bonds between coordinated water molecules and carboxylic acid O atoms, with O···O distances ranging from 2.744 (2) to 3.031 (3) Å; (c) hydrogen bonds between coordinated water and hydroxyl atom O5, with an O···O distance of 2.886 (3) Å; (d) hydrogen bond between isolated water molecules and carboxylic acid oxygen atoms, with O···O distances of 2.754 (3) and 2.865 (3) Å; (e) hydrogen bonds between the hydroxyl and carboxylic acid groups, with an O···O distance of 2.675 (2) Å. These hydrogen-bonding interactions result in a three-dimensional network (Fig. 2).

S2. Experimental

A mixture of 4-hydroxyisophthalic acid (0.25 mmol, 0.045 g), Co(NO₃)₂·6H₂O (0.2 mmol, 0.05 g) and H₂O (20 ml) was sealed in a 25 ml Teflon-lined stainless-steel reator and heated at 433 K for 72 h, and a red solution was obtained. After cooling and evaporating the red solution for two weeks, red crystals were isolated by filtration (yield, 50%).

S3. Refinement

The H atoms were located in an electron-density difference map. The H atoms of C—H and hydroxyl O—H groups were placed in calculated positions (C—H = 0.96 Å and O—H = 0.82 Å) and were allowed to refine as riding models, with displacement parameters fixed at 120% of those of their parent atoms. The H atoms of the water molecules (free and coordinated) were refined with O—H distances restrained to 0.84 (1) Å and H···H distances restrained to 1.37 (1) Å with displacement parameters fixed at 150% of the attached O atoms. These restraints ensure a reasonable geometry for the water molecules.

Computing details

Data collection: SMART (Siemens, 1996); cell refinement: SMART; data reduction: SAINT (Siemens, 1994; program(s) used to solve structure: SHELXTL (Siemens, 1994); program(s) used to refine structure: SHELXTL; molecular graphics: ORTEP-3 (Farrugia, 1997) and ORTEPIII (Burnett & Johnson, 1996); software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. A view of the cobalt ion coordination. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. Packing of the title complex, showing the three-dimensional hydrogen-bonding network.

Hexaaquabis(4-hydroxyisophthalato)cobalt(II) tetrahydrate

Crystal data

[Co(C8H5O5)2(H2O)6]·4H2O	Z = 1
Mr = 601.33	F(000) = 313
Triclinic, P1	Dx = 1.650 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.1863 (6) Å	Cell parameters from 34 reflections
b = 8.5173 (7) Å	θ = 2.1–25.0°
c = 9.8959 (7) Å	µ = 0.80 mm^−1
α = 92.088 (1)°	T = 293 K
β = 91.424 (1)°	Block, red
γ = 90.548 (1)°	0.28 × 0.16 × 0.10 mm
V = 605.08 (8) Å^3

Data collection

Siemens SMART CCD area-detector diffractometer	2076 independent reflections
Radiation source: fine-focus sealed tube	1847 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.019
ϕ and ω scans	θmax = 25.0°, θmin = 2.1°
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	h = −7→8
Tmin = 0.857, Tmax = 0.923	k = −10→10
3102 measured reflections	l = −11→11

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)] = 0.035	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.095	H atoms treated by a mixture of independent and constrained refinement
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0524P)^2 + 0.2322P] where P = (Fo^2 + 2Fc^2)/3
2076 reflections	(Δ/σ)max < 0.001
203 parameters	Δρmax = 0.54 e Å^−3
14 restraints	Δρmin = −0.43 e Å^−3

Special details

Experimental. empirical from equivalent reflections (XEMP in SHELXTL; Siemens, 1994)

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
Co	0.5000	0.5000	1.0000	0.02648 (16)
O1	0.1015 (3)	−0.3432 (2)	0.40678 (18)	0.0401 (5)
H1	0.0397	−0.4247	0.4009	0.060*
OW1	0.2519 (3)	−0.1236 (3)	0.1004 (2)	0.0565 (6)
HW1A	0.254 (5)	−0.034 (3)	0.142 (4)	0.085*
HW1B	0.159 (4)	−0.124 (4)	0.046 (3)	0.085*
O2	0.0788 (3)	−0.3815 (2)	0.62732 (18)	0.0409 (5)
OW2	−0.0166 (3)	−0.2883 (3)	−0.0519 (2)	0.0469 (5)
HW2A	−0.078 (4)	−0.342 (4)	0.001 (3)	0.070*
HW2B	−0.086 (4)	−0.259 (4)	−0.115 (2)	0.070*
O3	0.3804 (3)	0.3555 (2)	0.38148 (18)	0.0393 (5)
O4	0.2847 (3)	0.16327 (19)	0.23697 (16)	0.0339 (4)
O5	0.3719 (3)	0.3212 (2)	0.63382 (18)	0.0416 (5)
H5	0.3883	0.3660	0.5631	0.062*
O6	0.4793 (3)	0.2650 (2)	1.0299 (2)	0.0407 (5)
H6A	0.556 (4)	0.202 (3)	0.996 (3)	0.061*
H6B	0.438 (4)	0.227 (3)	1.101 (2)	0.061*
O7	0.2503 (3)	0.4795 (2)	0.87847 (18)	0.0393 (4)
H7A	0.259 (5)	0.449 (4)	0.7975 (15)	0.059*
H7B	0.181 (5)	0.553 (4)	0.888 (3)	0.059*
O8	0.3296 (3)	0.5436 (2)	1.16465 (17)	0.0340 (4)
H8A	0.301 (4)	0.6371 (15)	1.181 (3)	0.051*
H8B	0.339 (5)	0.495 (3)	1.2368 (18)	0.051*
C1	0.1221 (3)	−0.2977 (3)	0.5342 (2)	0.0287 (5)
C2	0.1972 (3)	−0.1373 (3)	0.5573 (2)	0.0265 (5)
C3	0.2296 (3)	−0.0411 (3)	0.4507 (2)	0.0258 (5)
H3	0.2107	−0.0808	0.3626	0.031*
C4	0.2898 (3)	0.1139 (3)	0.4720 (2)	0.0249 (5)
C5	0.3194 (3)	0.2170 (3)	0.3556 (2)	0.0292 (5)
C6	0.3162 (3)	0.1722 (3)	0.6056 (2)	0.0295 (5)
C7	0.2848 (4)	0.0751 (3)	0.7138 (2)	0.0370 (6)
H7	0.3044	0.1138	0.8021	0.044*
C8	0.2253 (4)	−0.0766 (3)	0.6901 (2)	0.0339 (6)
H8	0.2032	−0.1400	0.7627	0.041*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Co	0.0321 (3)	0.0258 (3)	0.0218 (3)	−0.00166 (18)	0.00285 (18)	0.00369 (17)
O1	0.0594 (13)	0.0296 (9)	0.0312 (10)	−0.0120 (9)	0.0071 (9)	0.0001 (7)
OW1	0.0534 (14)	0.0512 (13)	0.0632 (15)	0.0030 (11)	0.0020 (11)	−0.0235 (11)
O2	0.0571 (12)	0.0332 (10)	0.0327 (10)	−0.0143 (9)	0.0000 (8)	0.0107 (8)
OW2	0.0396 (11)	0.0552 (13)	0.0461 (12)	−0.0059 (9)	−0.0052 (9)	0.0118 (10)
O3	0.0600 (12)	0.0244 (9)	0.0336 (10)	−0.0112 (8)	0.0004 (8)	0.0049 (7)
O4	0.0497 (11)	0.0287 (9)	0.0235 (9)	−0.0044 (8)	0.0036 (8)	0.0033 (7)
O5	0.0631 (13)	0.0314 (10)	0.0299 (9)	−0.0161 (9)	0.0003 (9)	−0.0012 (7)
O6	0.0516 (12)	0.0299 (10)	0.0420 (11)	0.0020 (8)	0.0173 (9)	0.0097 (8)
O7	0.0448 (11)	0.0459 (11)	0.0270 (9)	0.0009 (9)	−0.0053 (8)	0.0018 (8)
O8	0.0467 (11)	0.0314 (9)	0.0245 (8)	0.0010 (8)	0.0075 (8)	0.0036 (7)
C1	0.0290 (12)	0.0276 (12)	0.0298 (13)	0.0000 (9)	0.0021 (10)	0.0050 (10)
C2	0.0272 (12)	0.0248 (11)	0.0278 (12)	−0.0010 (9)	−0.0005 (9)	0.0057 (9)
C3	0.0277 (12)	0.0267 (12)	0.0228 (11)	−0.0006 (9)	0.0006 (9)	0.0006 (9)
C4	0.0248 (11)	0.0251 (11)	0.0251 (12)	−0.0014 (9)	0.0013 (9)	0.0043 (9)
C5	0.0311 (12)	0.0280 (12)	0.0287 (13)	−0.0002 (10)	0.0030 (10)	0.0042 (10)
C6	0.0309 (13)	0.0267 (12)	0.0307 (13)	−0.0031 (10)	−0.0008 (10)	0.0010 (10)
C7	0.0504 (16)	0.0386 (14)	0.0219 (12)	−0.0093 (12)	−0.0023 (11)	0.0016 (10)
C8	0.0406 (14)	0.0361 (14)	0.0253 (12)	−0.0065 (11)	−0.0012 (10)	0.0087 (10)

Geometric parameters (Å, º)

Co—O6	2.0386 (18)	O6—H6B	0.841 (10)
Co—O8	2.0873 (17)	O7—H7A	0.837 (10)
Co—O7	2.1371 (18)	O7—H7B	0.81 (3)
Co—O7^i	2.1371 (18)	O8—H8A	0.835 (10)
O1—C1	1.310 (3)	O8—H8B	0.838 (10)
O1—H1	0.8200	C1—C2	1.472 (3)
OW1—HW1A	0.85 (2)	C2—C3	1.383 (3)
OW1—HW1B	0.85 (3)	C2—C8	1.404 (3)
O2—C1	1.230 (3)	C3—C4	1.392 (3)
OW2—HW2A	0.84 (3)	C3—H3	0.9300
OW2—HW2B	0.835 (10)	C4—C6	1.404 (3)
O3—C5	1.270 (3)	C4—C5	1.492 (3)
O4—C5	1.263 (3)	C6—C7	1.398 (4)
O5—C6	1.344 (3)	C7—C8	1.367 (4)
O5—H5	0.8200	C7—H7	0.9300
O6—H6A	0.84 (3)	C8—H8	0.9300
O6—Co—O6^i	180.0	O1—C1—C2	114.8 (2)
O6—Co—O8^i	90.38 (7)	C3—C2—C8	119.0 (2)
O6—Co—O8	89.62 (7)	C3—C2—C1	121.2 (2)
O6—Co—O7	88.04 (8)	C8—C2—C1	119.7 (2)
O6^i—Co—O7	91.96 (8)	C2—C3—C4	121.6 (2)
O8^i—Co—O7	93.09 (8)	C2—C3—H3	119.2
O8—Co—O7	86.91 (8)	C4—C3—H3	119.2
C1—O1—H1	109.5	C3—C4—C6	118.4 (2)
HW1A—OW1—HW1B	107 (2)	C3—C4—C5	120.8 (2)
HW2A—OW2—HW2B	110.1 (17)	C6—C4—C5	120.8 (2)
C6—O5—H5	109.5	O4—C5—O3	123.1 (2)
Co—O6—H6A	121 (2)	O4—C5—C4	119.2 (2)
Co—O6—H6B	123 (2)	O3—C5—C4	117.7 (2)
H6A—O6—H6B	109.0 (16)	O5—C6—C7	118.1 (2)
Co—O7—H7A	118 (2)	O5—C6—C4	121.7 (2)
Co—O7—H7B	114 (2)	C7—C6—C4	120.2 (2)
H7A—O7—H7B	113 (3)	C8—C7—C6	120.2 (2)
Co—O8—H8A	117 (2)	C8—C7—H7	119.9
Co—O8—H8B	123 (2)	C6—C7—H7	119.9
H8A—O8—H8B	110.0 (16)	C7—C8—C2	120.6 (2)
O2—C1—O1	122.6 (2)	C7—C8—H8	119.7
O2—C1—C2	122.5 (2)	C2—C8—H8	119.7
O2—C1—C2—C3	−174.4 (2)	C6—C4—C5—O3	4.3 (4)
O1—C1—C2—C3	4.3 (3)	C3—C4—C6—O5	−179.2 (2)
O2—C1—C2—C8	1.4 (4)	C5—C4—C6—O5	−1.2 (4)
O1—C1—C2—C8	−179.9 (2)	C3—C4—C6—C7	0.9 (4)
C8—C2—C3—C4	0.2 (4)	C5—C4—C6—C7	178.9 (2)
C1—C2—C3—C4	176.0 (2)	O5—C6—C7—C8	179.0 (2)
C2—C3—C4—C6	−0.5 (3)	C4—C6—C7—C8	−1.1 (4)
C2—C3—C4—C5	−178.5 (2)	C6—C7—C8—C2	0.8 (4)
C3—C4—C5—O4	1.8 (4)	C3—C2—C8—C7	−0.4 (4)
C6—C4—C5—O4	−176.2 (2)	C1—C2—C8—C7	−176.3 (2)
C3—C4—C5—O3	−177.7 (2)

Symmetry code: (i) −x+1, −y+1, −z+2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O2^ii	0.82	1.86	2.675 (2)	173
O5—H5···O3	0.82	1.80	2.527 (2)	148
O6—H6A···OW1^iii	0.84 (3)	1.82 (3)	2.627 (3)	161 (3)
O6—H6B···O4^iv	0.84 (1)	1.86 (1)	2.674 (2)	164 (3)
O7—H7A···O5	0.84 (1)	2.10 (2)	2.886 (3)	156 (3)
O7—H7A···O2^v	0.84 (1)	2.59 (3)	3.031 (3)	115 (3)
O7—H7B···OW2^vi	0.81 (3)	2.05 (3)	2.847 (3)	167 (3)
O8—H8A···OW1^vi	0.84 (1)	2.25 (2)	2.982 (3)	147 (2)
O8—H8B···O3^iv	0.84 (1)	1.92 (1)	2.744 (2)	169 (3)
OW2—HW2A···O7^vii	0.84 (3)	2.12 (3)	2.952 (3)	175 (3)
OW2—HW2B···O4^viii	0.84 (1)	2.04 (3)	2.865 (3)	167 (4)
OW1—HW1A···O4	0.85 (2)	1.90 (2)	2.754 (3)	174 (4)
OW1—HW1B···OW2	0.85 (3)	2.07 (3)	2.759 (3)	138 (3)

Symmetry codes: (ii) −x, −y−1, −z+1; (iii) −x+1, −y, −z+1; (iv) x, y, z+1; (v) x, y+1, z; (vi) x, y+1, z+1; (vii) −x, −y, −z+1; (viii) −x, −y, −z.