Poly[trans-diaquabis­[μ₂-2-(pyridin-3-yl)acetato-κ² N:O]­zinc]

Abstract

In the title coordination polymer, [Zn(C₇H₆NO₂)₂(H₂O)₂]_n, the Zn^II cation is located on an inversion center and is coordinated by four pyridyl­acetate anions and two water mol­ecules in a distorted ZnN₂O₄ octa­hedral geometry. The pyridine-N and carboxyl­ate-O atoms of the pyridyl­acetate anion connect to two Zn^II cations, forming a two-dimensional polymeric complex extending parallel to (212). Inter­molecular O—H⋯O and weak C—H⋯O hydrogen bonding is present in the crystal structure.

Related literature

For related complexes with pyridyl­acetate ligands, see: Li et al. (2004 ▶); Du et al. (2006 ▶); Martin et al. (2007 ▶); Qin et al. (2007 ▶); Aakeröy et al. (1999 ▶); Evans & Lin (2002 ▶); Tong et al. (2003 ▶).

Experimental

Crystal data

• [Zn(C₇H₆NO₂)₂(H₂O)₂]

• M _r = 373.66

• Monoclinic,

• a = 9.175 (2) Å

• b = 8.686 (2) Å

• c = 9.574 (2) Å

• β = 105.928 (3)°

• V = 733.8 (3) ų

• Z = 2

• Mo Kα radiation

• μ = 1.71 mm⁻¹

• T = 298 K

• 0.20 × 0.20 × 0.19 mm

Data collection

• Bruker APEXII CCD area-detector diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2001 ▶) T _min = 0.718, T _max = 0.723

• 4934 measured reflections

• 1732 independent reflections

• 1178 reflections with I > 2σ(I)

• R _int = 0.054

Refinement

• R[F ² > 2σ(F ²)] = 0.042

• wR(F ²) = 0.098

• S = 1.00

• 1732 reflections

• 112 parameters

• 3 restraints

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

• Δρ_max = 0.39 e Å⁻³

• Δρ_min = −0.38 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; 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—N1	2.168 (3)
Zn1—O2i	2.091 (2)
Zn1—O3	2.125 (2)

Symmetry code: (i) .

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3B⋯O1i	0.81 (3)	1.99 (3)	2.739 (4)	152 (4)
O3—H3C⋯O1ii	0.82 (3)	1.97 (3)	2.764 (4)	161 (3)
C1—H1A⋯O1iii	0.93	2.54	3.443 (5)	163
C3—H3A⋯O1iv	0.93	2.50	3.366 (5)	155

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

supplementary crystallographic information

Comment

The compounds of pyridine-carboxylic acids have been extensively utilized in the preparation of metal complexes due to their versatile coordination modes. Though various metal-pyridinepolycarboxylate complexes have been reported (Evans et al., 2002; Aakeröy et al., 1999; Li et al., 2004; Du et al., 2006), 3-pyridylacetate complexes are rare. Only a few of complexes as nickel, cobalt and copper species have been combined up to now (Martin et al., 2007). In this paper, we described a new two-dimensional coordination polymer, [Zn(3-pyridylacetato)₂(H₂O)₂]_n, (I). The molecular structure of the title complex is similar to those previously reported such as [M(4-pyridylacetato)₂(H₂O)₂]_n (M = Cu, Co, Mn, Ni, Zn, Cd)(Du et al., 2006; Qin et al., 2007; Tong et al., 2003) and [M(3-pyridylacetato)₂(H₂O)₂]_n (M = Ni, Co, Cu) (Martin et al., 2007;). Single-crystal X-ray diffraction analysis shows that the title compound is crystallized in a space group P2₁/n. The Zn^II center is six-coordinated by two water molecules in the axial positions, two pyridyl nitrogen atoms and two carboxylate oxygen atoms from two 3-pyridylacetate ligands in the plane. Pyridine nitrogen atom and carboxylate oxygen atom of each 3-pyridylacetate anion are connected to one Zn^II ions. The coordination geometry of Zn^II cation can been described as a distorted octahedral geometry with Zn—N and Zn—O distance range 2.168 (2) Å and 2.091 (3)—2.125 (3) Å, respectively (Fig. 1, Table 1). Four 3-pyridylacetate anionic ligands and four Zn^II ions are combined to a tetragon, which is of a side length of 8.653 Å and a diagonal measurement of 14.969*8.686 Å based on the Zn—Zn distances. The tetragon is further extended into a two-dimensional framework structure parallel to (212) with arhombic grid through sharing Zn^II ions, 3-pyridylacetate anionic ligands. Adjacent two-dimensional layers are connected by the intermolecular O—H···O and weak C—H···O hydrogen-bonding contacts, forming a three-dimensional framework structure with oxygen as a trifurcated acceptor atom (Fig. 2)

Experimental

A mixture of Zn(COO)₂.H₂O (0.1 mmol), 3-pyridyl acetic acid (0.1 mmol), DMF (5.0 ml) and methanol (10.0 ml) was stirred for 30 min and and the crude product was isolated by filtration. The filtrate was purified by recrystallization from anhydrous methanol and DMF to give (I) as colorless block crystals in 60% yield. An solution of (I) was stood at room temperature, and upon slowly evaporating methanol and DMF from the solution, colorless block crystals suitable for X-ray diffraction analysis were isolated in room temperature three week later.

Refinement

Water H atoms were located in a difference Fourier map and positional parameters were refined, U_iso(H) = 1.2U_eq(O). Other H atoms were generated geometrically and were included in therefinement in the riding model approximation with C—H = 0.93–0.97 Å, U_iso= 1.2U_eq(C).

Figures

Fig. 1.

The molecular structure of the title complex with the atom-numbering diagram. Ellipsoids were drawn at the 30% probability level.

Fig. 2.

The packing diagram of (I).

Crystal data

[Zn(C7H6NO2)2(H2O)2]	F(000) = 384
Mr = 373.66	Dx = 1.691 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 4934 reflections
a = 9.175 (2) Å	θ = 3.2–28.2°
b = 8.686 (2) Å	µ = 1.71 mm−1
c = 9.574 (2) Å	T = 298 K
β = 105.928 (3)°	Block, colorless
V = 733.8 (3) Å3	0.20 × 0.20 × 0.19 mm
Z = 2

Data collection

Bruker APEXII CCD area-detector diffractometer	1732 independent reflections
Radiation source: fine-focus sealed tube	1178 reflections with I > 2σ(I)
graphite	Rint = 0.054
φ and ω scans	θmax = 28.2°, θmin = 3.2°
Absorption correction: multi-scan (SADABS; Bruker, 2001)	h = −12→11
Tmin = 0.718, Tmax = 0.723	k = −11→11
4934 measured reflections	l = −9→12

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)] = 0.042	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.098	H atoms treated by a mixture of independent and constrained refinement
S = 1.00	w = 1/[σ2(Fo2) + (0.035P)2 + 0.2786P] where P = (Fo2 + 2Fc2)/3
1732 reflections	(Δ/σ)max < 0.001
112 parameters	Δρmax = 0.39 e Å−3
3 restraints	Δρmin = −0.38 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
Zn1	0.5000	0.0000	0.0000	0.02624 (18)
O1	0.2006 (3)	0.1719 (3)	0.6106 (3)	0.0400 (6)
O2	0.0333 (3)	0.2812 (3)	0.4230 (2)	0.0331 (6)
O3	0.6282 (3)	0.0534 (3)	0.2153 (3)	0.0359 (6)
H3C	0.694 (3)	0.002 (3)	0.272 (3)	0.043*
H3B	0.676 (4)	0.130 (3)	0.207 (4)	0.043*
N1	0.3007 (3)	0.0777 (3)	0.0596 (3)	0.0293 (6)
C1	0.1913 (4)	0.1572 (4)	−0.0326 (4)	0.0346 (8)
H1A	0.2032	0.1814	−0.1235	0.042*
C2	0.0611 (4)	0.2054 (4)	0.0003 (4)	0.0372 (9)
H2A	−0.0123	0.2612	−0.0670	0.045*
C3	0.0414 (4)	0.1699 (4)	0.1341 (4)	0.0346 (8)
H3A	−0.0460	0.2004	0.1578	0.042*
C4	0.1537 (4)	0.0881 (4)	0.2333 (3)	0.0267 (7)
C5	0.2802 (4)	0.0449 (4)	0.1900 (4)	0.0295 (8)
H5A	0.3557	−0.0104	0.2555	0.035*
C6	0.1407 (4)	0.0437 (4)	0.3815 (4)	0.0341 (9)
H6A	0.2296	−0.0158	0.4302	0.041*
H6B	0.0532	−0.0229	0.3692	0.041*
C7	0.1255 (4)	0.1768 (4)	0.4799 (4)	0.0278 (7)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Zn1	0.0299 (3)	0.0285 (3)	0.0225 (3)	−0.0017 (3)	0.0111 (2)	−0.0004 (2)
O1	0.0477 (16)	0.0369 (14)	0.0309 (14)	0.0064 (12)	0.0033 (12)	0.0006 (11)
O2	0.0417 (15)	0.0324 (13)	0.0259 (12)	0.0088 (11)	0.0106 (11)	−0.0015 (10)
O3	0.0426 (16)	0.0340 (14)	0.0279 (14)	−0.0022 (12)	0.0044 (11)	−0.0018 (11)
N1	0.0336 (17)	0.0316 (16)	0.0256 (15)	−0.0012 (13)	0.0130 (12)	0.0007 (12)
C1	0.045 (2)	0.034 (2)	0.0261 (18)	0.0034 (17)	0.0126 (16)	0.0024 (15)
C2	0.037 (2)	0.039 (2)	0.034 (2)	0.0102 (17)	0.0060 (16)	0.0004 (16)
C3	0.029 (2)	0.037 (2)	0.039 (2)	0.0047 (16)	0.0121 (16)	−0.0065 (17)
C4	0.033 (2)	0.0232 (18)	0.0263 (17)	0.0001 (14)	0.0123 (15)	−0.0021 (14)
C5	0.034 (2)	0.0275 (18)	0.0286 (18)	0.0025 (14)	0.0116 (15)	0.0035 (14)
C6	0.048 (2)	0.0259 (18)	0.035 (2)	0.0059 (16)	0.0234 (17)	0.0035 (14)
C7	0.0286 (19)	0.0282 (18)	0.0314 (19)	−0.0034 (15)	0.0160 (15)	0.0037 (15)

Geometric parameters (Å, °)

Zn1—N1	2.168 (3)	C1—C2	1.382 (5)
Zn1—N1i	2.168 (3)	C1—H1A	0.9300
Zn1—O2ii	2.091 (2)	C2—C3	1.377 (5)
Zn1—O2iii	2.091 (2)	C2—H2A	0.9300
Zn1—O3	2.125 (2)	C3—C4	1.390 (5)
O1—C7	1.252 (4)	C3—H3A	0.9300
O2—C7	1.258 (4)	C4—C5	1.387 (4)
O2—Zn1iv	2.091 (2)	C4—C6	1.507 (4)
O3—H3C	0.825 (18)	C5—H5A	0.9300
O3—H3B	0.812 (17)	C6—C7	1.522 (4)
N1—C1	1.333 (4)	C6—H6A	0.9700
N1—C5	1.344 (4)	C6—H6B	0.9700
O2ii—Zn1—O2iii	180.00 (12)	C1—C2—H2A	120.4
O2ii—Zn1—O3i	87.23 (9)	C2—C3—C4	119.2 (3)
O2iii—Zn1—O3i	92.77 (9)	C2—C3—H3A	120.4
O2ii—Zn1—N1i	88.57 (10)	C4—C3—H3A	120.4
O2iii—Zn1—N1i	91.43 (10)	C5—C4—C3	117.3 (3)
O3i—Zn1—N1i	87.67 (10)	C5—C4—C6	120.1 (3)
O2ii—Zn1—N1	91.43 (10)	C3—C4—C6	122.6 (3)
O2iii—Zn1—N1	88.57 (10)	N1—C5—C4	124.2 (3)
O3i—Zn1—N1	92.33 (10)	N1—C5—H5A	117.9
N1i—Zn1—N1	180.00 (12)	C4—C5—H5A	117.9
C7—O2—Zn1iv	130.4 (2)	C4—C6—C7	115.7 (3)
H3C—O3—H3B	101 (2)	C4—C6—H6A	108.4
C1—N1—C5	117.0 (3)	C7—C6—H6A	108.4
C1—N1—Zn1	121.5 (2)	C4—C6—H6B	108.4
C5—N1—Zn1	121.5 (2)	C7—C6—H6B	108.4
N1—C1—C2	123.1 (3)	H6A—C6—H6B	107.4
N1—C1—H1A	118.4	O1—C7—O2	125.3 (3)
C2—C1—H1A	118.4	O1—C7—C6	118.3 (3)
C3—C2—C1	119.1 (3)	O2—C7—C6	116.4 (3)
C3—C2—H2A	120.4

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

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3B···O1ii	0.81 (3)	1.99 (3)	2.739 (4)	152 (4)
O3—H3C···O1v	0.82 (3)	1.97 (3)	2.764 (4)	161 (3)
C1—H1A···O1vi	0.93	2.54	3.443 (5)	163
C3—H3A···O1vii	0.93	2.50	3.366 (5)	155

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