Diaqua­bis(5-methyl­pyridine-2-carboxyl­ato-κ² N,O)zinc(II)

Abstract

In the title compound, [Zn(C₇H₆NO₂)₂(H₂O)₂], the Zn atom (site symmetry ) adopts a distorted trans-ZnN₂O₄ octa­hedral coordination arising from two N,O-bidentate 5-methyl­pyridine-2-carboxyl­ate ligands and two water mol­ecules. In the crystal structure, mol­ecules form a layered network linked by O—H⋯O hydrogen bonds.

Related literature

For background, see: Hagrman et al. (1998 ▶); Ranford et al. (1998 ▶).

Experimental

Crystal data

• [Zn(C₇H₆NO₂)₂(H₂O)₂]

• M _r = 373.66

• Triclinic,

• a = 5.1703 (6) Å

• b = 6.4620 (10) Å

• c = 12.2781 (14) Å

• α = 104.678 (2)°

• β = 90.646 (1)°

• γ = 109.493 (2)°

• V = 372.01 (8) ų

• Z = 1

• Mo Kα radiation

• μ = 1.68 mm⁻¹

• T = 298 (2) K

• 0.49 × 0.46 × 0.27 mm

Data collection

• Bruker SMART CCD diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2000 ▶) T _min = 0.493, T _max = 0.659

• 1917 measured reflections

• 1275 independent reflections

• 1260 reflections with I > 2σ(I)

• R _int = 0.013

Refinement

• R[F ² > 2σ(F ²)] = 0.034

• wR(F ²) = 0.097

• S = 1.15

• 1275 reflections

• 108 parameters

• H-atom parameters constrained

• Δρ_max = 0.63 e Å⁻³

• Δρ_min = −0.60 e Å⁻³

Data collection: SMART (Bruker, 2000 ▶); cell refinement: SAINT (Bruker, 2000 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

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

Table 1. Selected bond lengths (Å).

Zn1—O1	2.104 (2)
Zn1—O3	2.134 (2)
Zn1—N1	2.116 (2)

Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3A⋯O2i	0.85	1.88	2.693 (4)	160
O3—H3B⋯O1ii	0.85	1.94	2.757 (3)	160

Symmetry codes: (i) ; (ii) .

supplementary crystallographic information

Comment

As part of our efforts to achieve supramolecular transition metal complexes by self-assembly (Ranford, et al., 1998; Hagrman, et al., 1998), we now report on the synthesis and crystal structure of the title compound, (I), (Fig. 1).

The Zn^II centre in (I) is six-coordinate with two O donors of H₂O, and two N,O-bidentate ligands (Table 1). In the crystal packing, the molecules form a layers linked by O—H···O hydrogen bonds (Table 2).

Experimental

A solution of 1.0 mmol 5-methylpyridine-2-carboxylic acid and 1.0 mmol NaOH in 5 ml 95% ethanol was added to a solution of 0.5 mmol Zn(CH₃COO)₂.4H₂O in 5 ml ethanol at room temperature. The mixture was refluxed for 2 h with stirring, then the resulting precipitate was filtered, washed, and dried in vacuo over P₄O₁₀ for 48 h. Colourless blocks of (I) were obtained by slowly evaporating from methanol at room temperature.

Refinement

The H atoms were geometrically placed (C—H = 0.93-0.96Å, O—H = 0.85Å) and refined as riding with U_iso(H) = 1.2U_eq(C, O) or 1.5U_eq(methyl C).

Figures

Fig. 1.

The molecular structure of (I) showing 50% displacement ellipsoids for the non-hydrogen atoms. Symmetry code: (i) 1–x, 1–y, 1–z.

Crystal data

[Zn(C7H6NO2)2(H2O)2]	Z = 1
Mr = 373.66	F(000) = 192
Triclinic, P1	Dx = 1.668 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 5.1703 (6) Å	Cell parameters from 1975 reflections
b = 6.462 (1) Å	θ = 3.4–27.9°
c = 12.2781 (14) Å	µ = 1.68 mm−1
α = 104.678 (2)°	T = 298 K
β = 90.646 (1)°	Block, colourless
γ = 109.493 (2)°	0.49 × 0.46 × 0.27 mm
V = 372.01 (8) Å3

Data collection

Bruker SMART CCD diffractometer	1275 independent reflections
Radiation source: fine-focus sealed tube	1260 reflections with I > 2σ(I)
graphite	Rint = 0.013
ω scans	θmax = 25.0°, θmin = 1.7°
Absorption correction: multi-scan (SADABS; Bruker, 2000)	h = −6→3
Tmin = 0.493, Tmax = 0.659	k = −6→7
1917 measured reflections	l = −14→14

Refinement

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.034	H-atom parameters constrained
wR(F2) = 0.097	w = 1/[σ2(Fo2) + (0.0603P)2 + 0.3083P] where P = (Fo2 + 2Fc2)/3
S = 1.15	(Δ/σ)max < 0.001
1275 reflections	Δρmax = 0.63 e Å−3
108 parameters	Δρmin = −0.60 e Å−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.094 (11)

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
Zn1	0.5000	0.5000	0.5000	0.0269 (2)
N1	0.4060 (5)	0.5257 (4)	0.6691 (2)	0.0265 (5)
C4	0.3260 (7)	0.5138 (6)	0.8903 (2)	0.0351 (7)
H4	0.2979	0.5079	0.9643	0.042*
O1	0.6819 (4)	0.2811 (3)	0.54326 (17)	0.0298 (5)
O2	0.7442 (5)	0.1369 (4)	0.6842 (2)	0.0399 (6)
O3	0.1258 (4)	0.2198 (4)	0.4350 (2)	0.0368 (5)
H3A	0.1410	0.0905	0.4068	0.044*
H3B	−0.0199	0.2048	0.4683	0.044*
C1	0.6533 (6)	0.2552 (5)	0.6414 (2)	0.0266 (6)
C2	0.4953 (6)	0.3907 (5)	0.7150 (2)	0.0269 (6)
C3	0.4520 (8)	0.3852 (6)	0.8251 (3)	0.0417 (8)
H3	0.5124	0.2887	0.8550	0.050*
C6	0.2809 (6)	0.6541 (5)	0.7341 (3)	0.0309 (6)
H6	0.2175	0.7490	0.7040	0.037*
C5	0.2430 (6)	0.6500 (6)	0.8452 (3)	0.0351 (7)
C7	0.1086 (8)	0.8011 (7)	0.9188 (3)	0.0500 (9)
H7A	−0.0093	0.7186	0.9650	0.075*
H7B	0.0010	0.8473	0.8718	0.075*
H7C	0.2483	0.9337	0.9664	0.075*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Zn1	0.0346 (3)	0.0309 (3)	0.0229 (3)	0.0191 (2)	0.00841 (19)	0.01007 (19)
N1	0.0300 (12)	0.0281 (12)	0.0253 (12)	0.0143 (10)	0.0049 (10)	0.0083 (10)
C4	0.0477 (18)	0.0513 (19)	0.0163 (13)	0.0286 (15)	0.0102 (12)	0.0108 (13)
O1	0.0357 (11)	0.0321 (11)	0.0293 (11)	0.0209 (9)	0.0098 (8)	0.0089 (9)
O2	0.0559 (14)	0.0394 (12)	0.0369 (12)	0.0323 (11)	0.0035 (10)	0.0111 (10)
O3	0.0337 (11)	0.0298 (11)	0.0486 (13)	0.0161 (9)	0.0117 (10)	0.0067 (10)
C1	0.0274 (13)	0.0224 (13)	0.0306 (15)	0.0109 (11)	0.0018 (11)	0.0052 (11)
C2	0.0304 (14)	0.0264 (13)	0.0252 (14)	0.0119 (11)	0.0036 (11)	0.0066 (11)
C3	0.054 (2)	0.051 (2)	0.0337 (17)	0.0306 (17)	0.0084 (15)	0.0194 (15)
C6	0.0349 (15)	0.0321 (15)	0.0313 (15)	0.0196 (12)	0.0078 (12)	0.0076 (12)
C5	0.0341 (15)	0.0399 (17)	0.0289 (15)	0.0146 (13)	0.0065 (12)	0.0029 (13)
C7	0.054 (2)	0.059 (2)	0.0395 (19)	0.0315 (19)	0.0155 (16)	0.0005 (17)

Geometric parameters (Å, °)

Zn1—O1	2.104 (2)	O2—C1	1.232 (4)
Zn1—O3	2.134 (2)	O3—H3A	0.8499
Zn1—O1i	2.104 (2)	O3—H3B	0.8499
Zn1—N1i	2.116 (2)	C1—C2	1.531 (4)
Zn1—N1	2.116 (2)	C2—C3	1.380 (4)
Zn1—O3i	2.134 (2)	C3—H3	0.9300
N1—C6	1.334 (4)	C6—C5	1.387 (5)
N1—C2	1.343 (4)	C6—H6	0.9300
C4—C5	1.327 (5)	C5—C7	1.507 (4)
C4—C3	1.338 (5)	C7—H7A	0.9600
C4—H4	0.9300	C7—H7B	0.9600
O1—C1	1.262 (4)	C7—H7C	0.9600
O1—Zn1—O1i	180.0	Zn1—O3—H3B	121.9
O1—Zn1—N1i	100.78 (8)	H3A—O3—H3B	110.5
O1i—Zn1—N1i	79.22 (8)	O2—C1—O1	126.8 (3)
O1—Zn1—N1	79.22 (8)	O2—C1—C2	117.3 (3)
O1i—Zn1—N1	100.78 (8)	O1—C1—C2	115.9 (2)
N1i—Zn1—N1	180.0	N1—C2—C3	120.1 (3)
O1—Zn1—O3i	89.38 (9)	N1—C2—C1	116.9 (2)
O1i—Zn1—O3i	90.62 (9)	C3—C2—C1	123.0 (3)
N1i—Zn1—O3i	92.23 (9)	C4—C3—C2	122.3 (3)
N1—Zn1—O3i	87.77 (9)	C4—C3—H3	118.8
O1—Zn1—O3	90.62 (9)	C2—C3—H3	118.8
O1i—Zn1—O3	89.38 (9)	N1—C6—C5	121.7 (3)
N1i—Zn1—O3	87.77 (9)	N1—C6—H6	119.1
N1—Zn1—O3	92.23 (9)	C5—C6—H6	119.1
O3i—Zn1—O3	180.0	C4—C5—C6	120.9 (3)
C6—N1—C2	117.7 (2)	C4—C5—C7	117.9 (3)
C6—N1—Zn1	130.4 (2)	C6—C5—C7	121.2 (3)
C2—N1—Zn1	111.95 (18)	C5—C7—H7A	109.5
C5—C4—C3	117.3 (3)	C5—C7—H7B	109.5
C5—C4—H4	121.3	H7A—C7—H7B	109.5
C3—C4—H4	121.3	C5—C7—H7C	109.5
C1—O1—Zn1	115.99 (17)	H7A—C7—H7C	109.5
Zn1—O3—H3A	116.6	H7B—C7—H7C	109.5
O1—Zn1—N1—C6	176.5 (3)	C6—N1—C2—C1	−176.5 (2)
O1i—Zn1—N1—C6	−3.5 (3)	Zn1—N1—C2—C1	2.3 (3)
O3i—Zn1—N1—C6	86.7 (3)	O2—C1—C2—N1	177.6 (3)
O3—Zn1—N1—C6	−93.3 (3)	O1—C1—C2—N1	−0.9 (4)
O1—Zn1—N1—C2	−2.21 (19)	O2—C1—C2—C3	0.0 (4)
O1i—Zn1—N1—C2	177.79 (19)	O1—C1—C2—C3	−178.5 (3)
O3i—Zn1—N1—C2	−92.0 (2)	C5—C4—C3—C2	−0.2 (6)
O3—Zn1—N1—C2	88.0 (2)	N1—C2—C3—C4	−1.1 (5)
N1i—Zn1—O1—C1	−178.1 (2)	C1—C2—C3—C4	176.4 (3)
N1—Zn1—O1—C1	1.9 (2)	C2—N1—C6—C5	0.0 (4)
O3i—Zn1—O1—C1	89.7 (2)	Zn1—N1—C6—C5	−178.6 (2)
O3—Zn1—O1—C1	−90.3 (2)	C3—C4—C5—C6	1.3 (5)
Zn1—O1—C1—O2	−179.4 (2)	C3—C4—C5—C7	−178.2 (3)
Zn1—O1—C1—C2	−1.2 (3)	N1—C6—C5—C4	−1.3 (5)
C6—N1—C2—C3	1.2 (4)	N1—C6—C5—C7	178.2 (3)
Zn1—N1—C2—C3	−180.0 (2)

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
O3—H3A···O2ii	0.85	1.88	2.693 (4)	160
O3—H3B···O1iii	0.85	1.94	2.757 (3)	160

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