Di­aqua-trans-bis­(pyridazine-3-carboxyl­ato-κ²O,N)­zinc(II)

In the structure of the title compound, [Zn(C₅H₃N₂O₂)₂(H₂O)₂], the Zn^II ion is located on a centre of symmetry. The coordin­ation around the Zn^II atom is slightly distorted octahedral, with two equatorial pyridazine-3-carboxyl­ate ligands in a trans arrangement. A pyridazine-ring N atom [Zn—N = 2.0742 (15) Å] and one carboxyl­ate O atom [Zn1—O2 = 2.0744 (14) Å] from each ligand coordinate to the metal. Two water O atoms [Zn—O = 2.1934 (17) Å] are coordinated in axial positions. The coordinated water mol­ecules act as hydrogen-bond donors to the unbonded carboxyl­ate O atoms in adjacent monomers, forming a three-dimensional network.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.041
• wR factor = 0.113
• Data-to-parameter ratio = 13.7

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT029_ALERT_3_B _diffrn_measured_fraction_theta_full Low .......       0.95

Alert level C
PLAT164_ALERT_4_C Nr. of Refined C-H H-Atoms in Heavy-At Struct...          3
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.21

   0 ALERT level A = In general: serious problem
   1 ALERT level B = Potentially serious problem
   2 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: KM-4 Software (Kuma, 1996); cell refinement: KM-4 Software; data reduction: DATAPROC (Kuma, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP (Siemens, 1992); software used to prepare material for publication: SHELXL97.

Diaqua-trans-bis(pyridazine-3-carboxylato-κ²O,N)zinc(II)

Crystal data

[Zn(C5H3N2O2)2(H2O)2]	F(000) = 352
Mr = 347.61	Dx = 1.965 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 25 reflections
a = 5.227 (1) Å	θ = 6–13°
b = 11.709 (2) Å	µ = 2.13 mm^−1
c = 9.799 (2) Å	T = 293 K
β = 101.63 (3)°	Rectangular plate, colourless
V = 587.4 (2) Å^3	0.37 × 0.21 × 0.18 mm
Z = 2

Data collection

Kuma KM-4 four-circle diffractometer	1529 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.047
Graphite monochromator	θmax = 30.1°, θmin = 2.7°
ω/2θ scans	h = −7→0
Absorption correction: analytical (CrysAlis RED v. 169, Oxford Diffraction, 2000	k = 0→16
Tmin = 0.245, Tmax = 0.357	l = −13→13
1750 measured reflections	3 standard reflections every 200 reflections
1601 independent reflections	intensity decay: 3.0%

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)] = 0.042	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.114	H atoms treated by a mixture of independent and constrained refinement
S = 1.08	w = 1/[σ^2(Fo^2) + (0.0855P)^2 + 0.2546P] where P = (Fo^2 + 2Fc^2)/3
1601 reflections	(Δ/σ)max < 0.001
117 parameters	Δρmax = 1.19 e Å^−3
0 restraints	Δρmin = −1.88 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	0.5000	0.5000	0.02186 (15)
O1	0.2136 (3)	0.72033 (14)	0.75307 (19)	0.0349 (4)
O2	0.2934 (3)	0.56119 (12)	0.64458 (16)	0.0256 (3)
O3	0.1737 (3)	0.54229 (15)	0.32897 (17)	0.0287 (3)
N1	0.3818 (3)	0.33056 (13)	0.48610 (16)	0.0199 (3)
N2	0.2183 (3)	0.28544 (14)	0.55897 (18)	0.0243 (3)
C3	0.1676 (4)	0.17482 (18)	0.5435 (2)	0.0280 (4)
C4	0.2724 (4)	0.10534 (17)	0.4538 (2)	0.0288 (4)
C5	0.4409 (4)	0.15343 (17)	0.3801 (2)	0.0265 (4)
C6	0.4924 (3)	0.26915 (15)	0.40012 (17)	0.0198 (3)
C7	0.3221 (3)	0.66637 (16)	0.67342 (18)	0.0219 (3)
H3	0.045 (6)	0.145 (3)	0.601 (3)	0.039 (8)*
H4	0.241 (6)	0.025 (3)	0.443 (4)	0.029 (7)*
H5	0.515 (7)	0.108 (3)	0.313 (4)	0.055 (10)*
H31	0.031 (8)	0.508 (2)	0.337 (4)	0.030 (9)*
H32	0.148 (12)	0.605 (4)	0.321 (6)	0.086 (17)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Zn1	0.0259 (2)	0.0167 (2)	0.0278 (2)	−0.00176 (8)	0.01676 (14)	−0.00194 (9)
O1	0.0391 (8)	0.0347 (9)	0.0391 (8)	−0.0029 (6)	0.0276 (7)	−0.0105 (6)
O2	0.0287 (6)	0.0219 (6)	0.0322 (7)	−0.0017 (5)	0.0203 (5)	−0.0008 (5)
O3	0.0248 (7)	0.0282 (8)	0.0354 (8)	0.0004 (5)	0.0115 (6)	0.0045 (6)
N1	0.0218 (6)	0.0189 (7)	0.0225 (7)	−0.0008 (5)	0.0125 (5)	0.0001 (5)
N2	0.0258 (7)	0.0247 (8)	0.0269 (7)	−0.0028 (6)	0.0162 (6)	0.0004 (6)
C3	0.0299 (9)	0.0261 (9)	0.0318 (9)	−0.0047 (7)	0.0153 (7)	0.0018 (7)
C4	0.0344 (9)	0.0195 (8)	0.0351 (10)	−0.0048 (7)	0.0130 (8)	−0.0014 (7)
C5	0.0334 (9)	0.0207 (9)	0.0285 (9)	−0.0008 (7)	0.0138 (7)	−0.0045 (7)
C6	0.0207 (7)	0.0202 (8)	0.0206 (8)	−0.0005 (6)	0.0095 (6)	−0.0008 (6)
C7	0.0215 (7)	0.0257 (9)	0.0212 (7)	0.0002 (6)	0.0108 (6)	−0.0007 (6)

Geometric parameters (Å, º)

Zn1—N1^i	2.0742 (15)	N1—N2	1.329 (2)
Zn1—N1	2.0742 (15)	O3—H31	0.86 (4)
Zn1—O2	2.0744 (14)	O3—H32	0.75 (5)
Zn1—O2^i	2.0744 (14)	N2—C3	1.325 (3)
Zn1—O3^i	2.1934 (17)	C7—C6^i	1.520 (2)
Zn1—O3	2.1934 (17)	C4—C5	1.368 (3)
O2—C7	1.266 (2)	C4—C3	1.389 (3)
O1—C7	1.228 (2)	C4—H4	0.95 (4)
C6—N1	1.326 (2)	C5—H5	0.98 (4)
C6—C5	1.388 (3)	C3—H3	1.00 (3)
C6—C7^i	1.520 (2)
N1^i—Zn1—N1	180.0	C6—N1—N2	122.41 (15)
N1^i—Zn1—O2	79.28 (6)	C6—N1—Zn1	113.47 (11)
N1—Zn1—O2	100.72 (6)	N2—N1—Zn1	124.09 (12)
N1^i—Zn1—O2^i	100.72 (6)	Zn1—O3—H31	112 (3)
N1—Zn1—O2^i	79.28 (6)	Zn1—O3—H32	114 (4)
O2—Zn1—O2^i	180.0	H31—O3—H32	109 (5)
N1^i—Zn1—O3^i	89.44 (6)	C3—N2—N1	117.58 (16)
N1—Zn1—O3^i	90.56 (6)	O1—C7—O2	126.39 (18)
O2—Zn1—O3^i	89.30 (6)	O1—C7—C6^i	117.79 (17)
O2^i—Zn1—O3^i	90.70 (6)	O2—C7—C6^i	115.82 (15)
N1^i—Zn1—O3	90.56 (6)	C5—C4—C3	118.11 (18)
N1—Zn1—O3	89.44 (6)	C5—C4—H4	117 (2)
O2—Zn1—O3	90.70 (6)	C3—C4—H4	125 (2)
O2^i—Zn1—O3	89.30 (6)	C4—C5—C6	117.02 (17)
O3^i—Zn1—O3	180.0	C4—C5—H5	121 (2)
C7—O2—Zn1	115.72 (12)	C6—C5—H5	122 (2)
N1—C6—C5	121.51 (16)	N2—C3—C4	123.35 (18)
N1—C6—C7^i	115.68 (15)	N2—C3—H3	114.3 (19)
C5—C6—C7^i	122.81 (16)	C4—C3—H3	122.3 (19)

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H31···O2^ii	0.86 (4)	1.92 (4)	2.784 (2)	178 (4)
O3—H32···O1^iii	0.75 (3)	2.20 (5)	2.896 (2)	155 (5)

Symmetry codes: (ii) −x, −y+1, −z+1; (iii) x, −y+3/2, z−1/2.