Diaqua­bis­(2-oxo-2H-chromene-3-carboxyl­ato)zinc(II)

Abstract

In the title compound, [Zn(C₁₀H₅O₄)₂(H₂O)₂], the Zn^II atom lies on a crystallographic inversion center and is six-coordinated by two O atoms from water mol­ecules in the axial positions and four O atoms from two deprotonated coumarin-3-carb­oxy­late ligands in the equatorial plane, forming a slightly distorted octa­hedral coordination geometry. O—H⋯O hydrogen-bonding inter­actions involving the water mol­ecules form infinite chains parallel to [010].

Related literature

For related structures, see: Chu et al. (2010 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶); Etter (1990 ▶).

Experimental

Crystal data

• [Zn(C₁₀H₅O₄)₂(H₂O)₂]

• M _r = 479.70

• Triclinic,

• a = 6.6113 (13) Å

• b = 6.8404 (14) Å

• c = 10.392 (2) Å

• α = 85.64 (3)°

• β = 89.47 (3)°

• γ = 66.09 (3)°

• V = 428.27 (18) ų

• Z = 1

• Mo Kα radiation

• μ = 1.50 mm⁻¹

• T = 293 K

• 0.2 × 0.2 × 0.2 mm

Data collection

• Bruker APEXII CCD diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.741, T _max = 0.748

• 2642 measured reflections

• 1808 independent reflections

• 1793 reflections with I > 2σ(I)

• R _int = 0.013

Refinement

• R[F ² > 2σ(F ²)] = 0.022

• wR(F ²) = 0.061

• S = 1.12

• 1808 reflections

• 142 parameters

• H-atom parameters constrained

• Δρ_max = 0.42 e Å⁻³

• Δρ_min = −0.28 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEPIII (Burnett & Johnson, 1996 ▶), ORTEP-3 for Windows (Farrugia, 1997 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXTL (Sheldrick, 2008 ▶).

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1W—H1⋯O3i	0.82	1.88	2.6950 (17)	179
O1W—H2⋯O3ii	0.93	1.83	2.7473 (19)	168

Symmetry codes: (i) ; (ii) .

supplementary crystallographic information

Comment

In the past decades, numerous papers dealing with mononuclear zinc complexes have been published (Chu et al. 2010). Herein, we report the synthesis and crystal structure of a new mononuclear zinc complex.

In the title compound, [Zn(C₁₀H₅O₄)₂(H₂O)₂], each Zn^II atom lies on a crystallographic inversion center and is six-coordinated by two O atoms from water molecules in the axial positions and four O atoms from two deprotonated coumarin-3-carboxylic acid ligands in the equatorial plane, forming an octahedral coordination geometry (Fig. 1). O—H···O hydrogen bonds involving the water molecules build up chain parllel to the [0 1 0] axis (Table 1, Fig. 2). The O-H···O interactions results in the formation of R⁴₂(8) rings (Etter, 1990; Bernstein et al., 1995).

Experimental

The title complex was synthesized by carefully layering a solution of ZnSO₄.7H₂O (28.8 mg, 0.1 mmol) in ethanol solution (10 ml) on top of a solution of coumarin-3-carboxylic acid (19.0 mg, 0.1 mmol) and LiOH (8.4 mg, 0.2 mmol) in H₂O (10 ml) in a test-tube. After about one month at room temperature, colorless block-shaped single crystals suitable for X-ray investigation appeared at the boundary between ethanol solution and water with a yield of 27%.

Refinement

The H atoms were placed geometrically (C—H = 0.93 Å) and treated as riding with U_iso(H) = 1.2_eq(C) . H atoms of water molecule were located in difference Fourier maps and included in the subsequent refinement using restraints (O-H= 0.85 (1)Å and H···H= 1.40 (2)Å) with U_iso(H) = 1.5U_eq(O). In the last cycle of refinement they were treated as riding on their parent O atom.

Figures

Fig. 1.

Molecular view of (I) with the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are represented as small spheres of arbitrary radii. [Symmetry code: (i) -x+1, -y+1, -z+1]

Fig. 2.

Partial packing view of compound ( I ), showing the formation of chains along [010] built from hydrogen bonds, and the formation of R 24(8) rings. For the sake of clarity, H atoms not involved in hydrogen bonding have been omitted. [Symmetry codes: (ii) -x, -y+1, -z+1; (iii) x+1, y-1, z]

Crystal data

[Zn(C10H5O4)2(H2O)2]	Z = 1
Mr = 479.70	F(000) = 244
Triclinic, P1	Dx = 1.860 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.6113 (13) Å	Cell parameters from 2271 reflections
b = 6.8404 (14) Å	θ = 3.4–28.4°
c = 10.392 (2) Å	µ = 1.50 mm−1
α = 85.64 (3)°	T = 293 K
β = 89.47 (3)°	Block, colourless
γ = 66.09 (3)°	0.2 × 0.2 × 0.2 mm
V = 428.27 (18) Å3

Data collection

Bruker APEXII CCD diffractometer	1808 independent reflections
Radiation source: fine-focus sealed tube	1793 reflections with I > 2σ(I)
graphite	Rint = 0.013
φ and ω scans	θmax = 27.1°, θmin = 3.4°
Absorption correction: multi-scan (SADABS; Sheldrick, 2008)	h = −8→8
Tmin = 0.741, Tmax = 0.748	k = −8→8
2642 measured reflections	l = 0→13

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)] = 0.022	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.061	H-atom parameters constrained
S = 1.12	w = 1/[σ2(Fo2) + (0.0216P)2 + 0.2757P] where P = (Fo2 + 2Fc2)/3
1808 reflections	(Δ/σ)max < 0.001
142 parameters	Δρmax = 0.42 e Å−3
0 restraints	Δρmin = −0.28 e Å−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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
Zn1	0.5000	0.5000	0.5000	0.01047 (10)
O1	0.30343 (17)	0.68964 (17)	0.87151 (10)	0.0127 (2)
O1W	0.49536 (17)	0.22209 (17)	0.59641 (10)	0.0133 (2)
H1	0.3972	0.1951	0.5649	0.020*
H2	0.6183	0.1022	0.5763	0.020*
O2	0.45061 (18)	0.64366 (18)	0.68157 (10)	0.0141 (2)
O3	−0.17320 (17)	0.86870 (17)	0.50573 (10)	0.0134 (2)
O4	0.16868 (17)	0.63230 (18)	0.47583 (10)	0.0132 (2)
C1	−0.2479 (3)	0.7880 (2)	0.99672 (15)	0.0146 (3)
H1A	−0.3880	0.8073	0.9679	0.018*
C2	−0.2071 (3)	0.7889 (3)	1.12660 (15)	0.0168 (3)
H3A	−0.3203	0.8111	1.1850	0.020*
C3	0.0042 (3)	0.7564 (2)	1.17064 (15)	0.0161 (3)
H2A	0.0305	0.7567	1.2584	0.019*
C4	0.1753 (3)	0.7237 (2)	1.08507 (15)	0.0148 (3)
H11A	0.3160	0.7015	1.1143	0.018*
C5	0.1306 (2)	0.7250 (2)	0.95493 (14)	0.0119 (3)
C6	−0.0780 (2)	0.7579 (2)	0.90792 (14)	0.0122 (3)
C7	−0.1088 (2)	0.7641 (2)	0.77180 (14)	0.0120 (3)
H7A	−0.2480	0.7893	0.7385	0.014*
C8	0.0600 (2)	0.7342 (2)	0.68973 (14)	0.0109 (3)
C9	0.2798 (2)	0.6861 (2)	0.74172 (14)	0.0113 (3)
C10	0.0171 (2)	0.7468 (2)	0.54635 (14)	0.0105 (3)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Zn1	0.00736 (13)	0.01189 (14)	0.01013 (13)	−0.00175 (9)	0.00122 (8)	−0.00152 (9)
O1	0.0106 (5)	0.0164 (5)	0.0101 (5)	−0.0041 (4)	0.0009 (4)	−0.0028 (4)
O1W	0.0105 (5)	0.0139 (5)	0.0143 (5)	−0.0036 (4)	0.0005 (4)	−0.0016 (4)
O2	0.0099 (5)	0.0185 (5)	0.0133 (5)	−0.0048 (4)	0.0021 (4)	−0.0041 (4)
O3	0.0093 (5)	0.0143 (5)	0.0138 (5)	−0.0018 (4)	−0.0009 (4)	−0.0012 (4)
O4	0.0091 (5)	0.0168 (5)	0.0116 (5)	−0.0026 (4)	0.0013 (4)	−0.0032 (4)
C1	0.0139 (7)	0.0135 (7)	0.0155 (7)	−0.0046 (6)	0.0028 (6)	−0.0014 (6)
C2	0.0204 (8)	0.0135 (7)	0.0147 (7)	−0.0051 (6)	0.0069 (6)	−0.0015 (6)
C3	0.0247 (8)	0.0122 (7)	0.0098 (7)	−0.0059 (6)	0.0016 (6)	−0.0012 (5)
C4	0.0166 (7)	0.0133 (7)	0.0129 (7)	−0.0043 (6)	−0.0009 (6)	−0.0014 (6)
C5	0.0129 (7)	0.0092 (6)	0.0117 (7)	−0.0024 (5)	0.0034 (5)	−0.0017 (5)
C6	0.0133 (7)	0.0095 (6)	0.0129 (7)	−0.0036 (5)	0.0020 (5)	−0.0008 (5)
C7	0.0110 (7)	0.0108 (7)	0.0135 (7)	−0.0037 (5)	−0.0002 (5)	−0.0008 (5)
C8	0.0105 (7)	0.0100 (6)	0.0113 (6)	−0.0032 (5)	0.0004 (5)	−0.0016 (5)
C9	0.0123 (7)	0.0096 (6)	0.0105 (6)	−0.0026 (5)	0.0004 (5)	−0.0015 (5)
C10	0.0097 (6)	0.0108 (6)	0.0120 (7)	−0.0051 (5)	0.0006 (5)	−0.0009 (5)

Geometric parameters (Å, °)

Zn1—O4	2.0122 (12)	C1—C6	1.406 (2)
Zn1—O4i	2.0122 (12)	C1—H1A	0.9300
Zn1—O1Wi	2.0918 (12)	C2—C3	1.398 (2)
Zn1—O1W	2.0918 (12)	C2—H3A	0.9300
Zn1—O2	2.1548 (12)	C3—C4	1.388 (2)
Zn1—O2i	2.1548 (12)	C3—H2A	0.9300
O1—C9	1.3623 (18)	C4—C5	1.386 (2)
O1—C5	1.3801 (18)	C4—H11A	0.9300
O1W—H1	0.8200	C5—C6	1.391 (2)
O1W—H2	0.9269	C6—C7	1.426 (2)
O2—C9	1.2241 (18)	C7—C8	1.356 (2)
O3—C10	1.2501 (19)	C7—H7A	0.9300
O4—C10	1.2617 (19)	C8—C9	1.454 (2)
C1—C2	1.380 (2)	C8—C10	1.509 (2)
O4—Zn1—O4i	180.0	C3—C2—H3A	119.9
O4—Zn1—O1Wi	88.05 (5)	C4—C3—C2	120.84 (15)
O4i—Zn1—O1Wi	91.95 (5)	C4—C3—H2A	119.6
O4—Zn1—O1W	91.95 (5)	C2—C3—H2A	119.6
O4i—Zn1—O1W	88.05 (5)	C5—C4—C3	118.17 (15)
O1Wi—Zn1—O1W	180.00 (3)	C5—C4—H11A	120.9
O4—Zn1—O2	87.20 (5)	C3—C4—H11A	120.9
O4i—Zn1—O2	92.80 (5)	O1—C5—C4	117.34 (14)
O1Wi—Zn1—O2	90.89 (5)	O1—C5—C6	120.25 (13)
O1W—Zn1—O2	89.11 (5)	C4—C5—C6	122.41 (14)
O4—Zn1—O2i	92.80 (5)	C5—C6—C1	118.34 (14)
O4i—Zn1—O2i	87.20 (5)	C5—C6—C7	118.03 (14)
O1Wi—Zn1—O2i	89.11 (5)	C1—C6—C7	123.62 (14)
O1W—Zn1—O2i	90.89 (5)	C8—C7—C6	121.59 (14)
O2—Zn1—O2i	180.000 (1)	C8—C7—H7A	119.2
C9—O1—C5	122.65 (12)	C6—C7—H7A	119.2
Zn1—O1W—H1	109.5	C7—C8—C9	119.36 (14)
Zn1—O1W—H2	110.7	C7—C8—C10	119.39 (13)
H1—O1W—H3	99.9	C9—C8—C10	121.24 (13)
C9—O2—Zn1	122.37 (10)	O2—C9—O1	114.78 (13)
C10—O4—Zn1	131.42 (10)	O2—C9—C8	127.30 (14)
C2—C1—C6	120.10 (15)	O1—C9—C8	117.92 (13)
C2—C1—H1A	119.9	O3—C10—O4	124.05 (14)
C6—C1—H1A	119.9	O3—C10—C8	116.41 (13)
C1—C2—C3	120.13 (15)	O4—C10—C8	119.51 (13)
C1—C2—H3A	119.9

Symmetry codes: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1···O3ii	0.82	1.88	2.6950 (17)	179.
O1W—H2···O3iii	0.93	1.83	2.7473 (19)	168.

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