Bis(μ-pyridazine-3,6-carboxyl­ato-κ⁴N,O:N′,O′)bis­[diaqua­zinc(II)]

The title crystal structure, [Zn₂(C₆H₂N₂O₄)₂(H₂O)₄], is composed of discrete centrosymmetric mol­ecular dimers in which two Zn^II atoms are coordinated by two fully deprotonated pyridazine-3,6-dicarboxyl­ate ligands via N,O-bonding and two water O atoms in axial positions forming slightly distorted octa­hedral environments. In the crystal structure, a three-dimensional network is formed via inter­molecular O—H...O hydrogen bonds [H...O = 2.04 (4)–2.10 (5) Å]

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.031
• wR factor = 0.101
• Data-to-parameter ratio = 15.8

checkCIF/PLATON results

No syntax errors found





Alert level C
PLAT164_ALERT_4_C Nr. of Refined C-H H-Atoms in Heavy-At Struct...          2
PLAT764_ALERT_4_C Overcomplete CIF Bond List Detected (Rep/Expd) .       1.11 Ratio

Alert level G
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature .        293 K

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

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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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, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP (Siemens, 1992); software used to prepare material for publication: SHELXL97.

Bis(µ-pyridazine-3,6-carboxylato-κ⁴N,O:N',O')bis[diaquazinc(II)]

Crystal data

[Zn2(C6H2N2O4)2(H2O)4]	F(000) = 1072
Mr = 535.0	Dx = 2.061 Mg m^−3
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 25 reflections
a = 13.393 (3) Å	θ = 6–15°
b = 8.8039 (18) Å	µ = 2.86 mm^−1
c = 14.622 (3) Å	T = 293 K
V = 1724.2 (6) Å^3	Prismatic blocks, colourless
Z = 4	0.13 × 0.11 × 0.06 mm

Data collection

Kuma KM-4 four-circle diffractometer	1684 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.037
Graphite monochromator	θmax = 30.1°, θmin = 2.8°
profile data from ω/2θ scans	h = −1→18
Absorption correction: analytical (CrysAlis RED; Oxford Diffraction, 2000)	k = −1→12
Tmin = 0.687, Tmax = 0.836	l = −20→0
3043 measured reflections	3 standard reflections every 200 reflections
2535 independent reflections	intensity decay: 1.0%

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)] = 0.031	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.101	All H-atom parameters refined
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0667P)^2] where P = (Fo^2 + 2Fc^2)/3
2535 reflections	(Δ/σ)max < 0.001
160 parameters	Δρmax = 0.72 e Å^−3
0 restraints	Δρmin = −0.47 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	−0.10730 (2)	0.89412 (3)	0.568909 (17)	0.02040 (11)
N1	0.11458 (13)	1.0178 (2)	0.56881 (12)	0.0177 (4)
O1	−0.10837 (13)	0.8139 (2)	0.69930 (12)	0.0270 (4)
O4	0.36223 (16)	1.1413 (3)	0.58167 (15)	0.0368 (5)
N2	0.04241 (14)	0.9497 (2)	0.61516 (13)	0.0173 (3)
O3	0.25060 (13)	1.1575 (2)	0.46792 (13)	0.0285 (4)
C4	0.1445 (2)	0.9450 (3)	0.74853 (18)	0.0298 (5)
C8	0.27919 (18)	1.1216 (3)	0.54860 (18)	0.0237 (5)
C6	0.20155 (17)	1.0465 (3)	0.60844 (16)	0.0206 (4)
C3	0.05654 (17)	0.9116 (3)	0.70218 (16)	0.0207 (4)
C7	−0.03135 (18)	0.8302 (3)	0.74673 (16)	0.0227 (4)
C5	0.21954 (19)	1.0133 (3)	0.70041 (18)	0.0283 (5)
O2	−0.01872 (16)	0.7844 (3)	0.82600 (13)	0.0356 (5)
O6	−0.05148 (17)	0.6869 (3)	0.51541 (16)	0.0328 (4)
H5	0.277 (2)	1.043 (4)	0.724 (2)	0.027 (7)*
H4	0.151 (2)	0.925 (3)	0.816 (2)	0.026 (8)*
O5	−0.14545 (17)	1.1157 (2)	0.61885 (14)	0.0284 (4)
H51	−0.096 (4)	1.152 (5)	0.624 (3)	0.060 (15)*
H52	−0.185 (3)	1.156 (4)	0.589 (3)	0.035 (10)*
H61	−0.003 (3)	0.664 (4)	0.531 (2)	0.028 (9)*
H62	−0.054 (4)	0.690 (6)	0.465 (4)	0.075 (17)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Zn1	0.01681 (15)	0.02799 (16)	0.01639 (15)	−0.00343 (11)	−0.00077 (10)	0.00422 (10)
N1	0.0148 (8)	0.0230 (8)	0.0152 (8)	−0.0027 (7)	0.0008 (7)	0.0012 (7)
O1	0.0229 (8)	0.0352 (9)	0.0229 (8)	−0.0050 (8)	0.0006 (7)	0.0100 (7)
O4	0.0205 (9)	0.0537 (13)	0.0362 (11)	−0.0135 (9)	−0.0053 (8)	0.0048 (10)
N2	0.0165 (8)	0.0202 (8)	0.0151 (8)	−0.0005 (7)	0.0013 (7)	0.0024 (7)
O3	0.0207 (8)	0.0391 (10)	0.0258 (9)	−0.0090 (8)	0.0000 (7)	0.0074 (7)
C4	0.0305 (12)	0.0395 (13)	0.0194 (10)	−0.0066 (12)	−0.0076 (10)	0.0087 (11)
C8	0.0173 (10)	0.0293 (12)	0.0246 (11)	−0.0048 (9)	−0.0002 (8)	0.0010 (9)
C6	0.0176 (10)	0.0241 (10)	0.0201 (10)	−0.0010 (9)	−0.0008 (8)	0.0035 (9)
C3	0.0212 (10)	0.0238 (11)	0.0171 (10)	−0.0014 (8)	−0.0010 (8)	0.0044 (8)
C7	0.0244 (10)	0.0262 (11)	0.0174 (9)	−0.0022 (9)	0.0005 (8)	0.0064 (9)
C5	0.0228 (11)	0.0360 (14)	0.0260 (12)	−0.0068 (10)	−0.0087 (10)	0.0067 (11)
O2	0.0364 (10)	0.0499 (12)	0.0207 (8)	−0.0055 (9)	−0.0013 (7)	0.0166 (9)
O6	0.0307 (10)	0.0375 (11)	0.0301 (11)	0.0050 (9)	−0.0019 (9)	−0.0040 (9)
O5	0.0280 (10)	0.0300 (10)	0.0272 (9)	0.0058 (9)	−0.0030 (8)	0.0003 (8)

Geometric parameters (Å, º)

Zn1—O1	2.0332 (18)	O3—Zn1^i	2.0445 (18)
Zn1—O3^i	2.0445 (18)	C4—C5	1.366 (4)
Zn1—O6	2.121 (2)	C4—C3	1.391 (3)
Zn1—O5	2.145 (2)	C4—H4	1.01 (3)
Zn1—N1^i	2.1600 (18)	C8—C6	1.511 (3)
Zn1—N2	2.1720 (19)	C6—C5	1.397 (3)
N1—N2	1.324 (3)	C3—C7	1.524 (3)
N1—C6	1.325 (3)	C7—O2	1.239 (3)
N1—Zn1^i	2.1600 (18)	C5—H5	0.89 (3)
O1—C7	1.251 (3)	O6—H61	0.71 (4)
O4—C8	1.225 (3)	O6—H62	0.74 (5)
N2—C3	1.330 (3)	O5—H51	0.74 (5)
O3—C8	1.280 (3)	O5—H52	0.77 (4)
O1—Zn1—O3^i	99.39 (7)	C5—C4—H4	121.2 (19)
O1—Zn1—O6	92.84 (9)	C3—C4—H4	121.0 (19)
O3^i—Zn1—O6	92.43 (9)	O4—C8—O3	126.9 (2)
O1—Zn1—O5	89.71 (8)	O4—C8—C6	117.3 (2)
O3^i—Zn1—O5	93.92 (9)	O3—C8—C6	115.8 (2)
O6—Zn1—O5	172.68 (9)	N1—C6—C5	122.2 (2)
O1—Zn1—N1^i	176.92 (7)	N1—C6—C8	115.78 (19)
O3^i—Zn1—N1^i	77.99 (7)	C5—C6—C8	122.0 (2)
O6—Zn1—N1^i	88.90 (9)	N2—C3—C4	122.2 (2)
O5—Zn1—N1^i	88.87 (8)	N2—C3—C7	114.7 (2)
O1—Zn1—N2	78.04 (7)	C4—C3—C7	123.1 (2)
O3^i—Zn1—N2	177.10 (7)	O2—C7—O1	126.4 (2)
O6—Zn1—N2	89.04 (8)	O2—C7—C3	116.6 (2)
O5—Zn1—N2	84.78 (8)	O1—C7—C3	117.0 (2)
N1^i—Zn1—N2	104.54 (7)	C4—C5—C6	117.5 (2)
N2—N1—C6	120.27 (18)	C4—C5—H5	125 (2)
N2—N1—Zn1^i	127.36 (14)	C6—C5—H5	118 (2)
C6—N1—Zn1^i	112.27 (14)	Zn1—O6—H61	116 (3)
C7—O1—Zn1	118.30 (15)	Zn1—O6—H62	109 (4)
N1—N2—C3	120.03 (19)	H61—O6—H62	113 (5)
N1—N2—Zn1	128.06 (14)	Zn1—O5—H51	102 (3)
C3—N2—Zn1	111.87 (15)	Zn1—O5—H52	113 (3)
C8—O3—Zn1^i	117.94 (16)	H51—O5—H52	118 (4)
C5—C4—C3	117.7 (2)

Symmetry code: (i) −x, −y+2, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O5—H51···O2^ii	0.74 (5)	2.06 (5)	2.773 (3)	162 (5)
O5—H52···O3^iii	0.77 (4)	2.04 (4)	2.745 (3)	153 (4)
O6—H61···O4^iv	0.71 (4)	2.04 (4)	2.743 (3)	170 (4)
O6—H62···O2^v	0.74 (5)	2.10 (5)	2.816 (3)	163 (6)

Symmetry codes: (ii) −x, y+1/2, −z+3/2; (iii) x−1/2, −y+5/2, −z+1; (iv) −x+1/2, y−1/2, z; (v) x, −y+3/2, z−1/2.