Tetra­aqua­bis[4-(tetra­zol-1-yl)benzoato-κN⁴]nickel(II) dihydrate

In the title compound, [Ni(C₈H₅N₄O₂)₂(H₂O)₄]·2H₂O, the Ni^II ion lies on an inversion centre and is coordinated by two N atoms from two 4-(tetra­zol-1-yl)benzoate ligands and four O atoms from four water mol­ecules in a slightly distorted octa­hedral geometry. In addition, there are two uncoordinated water mol­ecules in the structure. The crystal structure is stabilized by inter­molecular O—H...O hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.031
• wR factor = 0.068
• Data-to-parameter ratio = 13.1

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.97
PLAT154_ALERT_1_C The su's on the Cell Angles are Equal  (x 10000)       3000 Deg.
PLAT180_ALERT_3_C Check Cell Rounding: # of Values Ending with 0 =          3
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.48
PLAT710_ALERT_4_C Delete 1-2-3 or 2-3-4 Linear Torsion Angle ... #          5
            N1  -NI1 -N1  -C1     11.00  0.00   2.656   1.555   1.555   1.555
PLAT710_ALERT_4_C Delete 1-2-3 or 2-3-4 Linear Torsion Angle ... #         10
            N1  -NI1 -N1  -N2      6.00  0.00   2.656   1.555   1.555   1.555
PLAT720_ALERT_4_C Number of Unusual/Non-Standard Label(s) ........          6

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
   8 ALERT level C = Check and explain
   2 ALERT level G = General alerts; check

   4 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
   4 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Metal-organic frameworks (MOFs) containing 1H-tetrazol and its derivatives have attracted great attentions of many research groups due to their intriguing structural diversity and potential applications in luminescence, magnetism and gas storage (Dinca, et al., 2006; Li, et al., 2007; Bronisz, 2007). However, there are rare reports of ligands based on tetrazol and carboxylate groups as building blocks for the construction of MOFs. So we synthesized several coordination compounds by such ligands. And here we report the structure of title compound (I).

The structure of (I) consists of discrete neutral unit [Ni(C₈H₅N₄O₂)₂(H₂O)₂] and two lattice water molecules (Fig. 1), atom Ni1 occupies an inversion centre and is coordinated by two N atoms from two 4-(tetrazol-1- yl)benzoate ligands and four O atoms from four water molecules in a distorted octahedral geometry. The Ni1—N1 distance of 2.0927 (15)Å is slightly lengthened, while the distances of Ni1—O1W and Ni1—O2W bonds (Table 1) is slightly shorten compared with the values observed in related complex (Zhang et al., 2007). The crystal stacking of (I) (Fig. 2) is stabilized by intermolecular O—H···O hydrogen bonds (Table 2) (Li, et al., 2006), which is similar to that in related reports (Zou, et al., 2005; Zhang, et al., 2007).

Related literature

For related literature, see: Zhang et al. (2007); Zou et al. (2005); Bronisz (2007); Dinca et al. (2006); Li et al. (2006, 2007).

S2. Experimental

A solution of NiCl₂.6H₂O (24 mg, 0.1 mmol) in water (5 ml) was added to a solution of 4-(tetrazol-1-yl) benzoic acid (38 mg, 0.2 mmol) and sodium hydroxide (8 mg, 0.2 mmol) in methanol (5 ml). The reaction mixture was stirred for 30 min and then filtered. Green crystals of (I) suitable for X-ray diffraction were obtained by slow evaporation after two weeks [yield: 40%].

S3. Refinement

H atoms bounded to C atoms were included in calculated positions and treated in the subsequent refinement as riding atoms, with C—H = 0.93 Å and U_iso(H) = 1.2U_eq(C). The H atoms of water was located in Fourier difference map and refined freely.

Computing details

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1998); data reduction: SAINT; program(s) used to solve structure: SHELXL97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1998); software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. The molecular structure of (I), with 40% probability displacement ellipsoids. [Symmetry code: (A) -x + 1, -y, -z + 1.]
	Fig. 2. A portion of the crystal stacking structure, showing the intermolecular O—H···O hydrogen bonds (dashed lines).

Tetraaquabis[4-(tetrazol-1-yl)benzoato-κN⁴]nickel(II) dihydrate

Crystal data

[Ni(C8H5N4O2)2(H2O)4]·2H2O	Z = 1
Mr = 545.13	F(000) = 282
Triclinic, P1	Dx = 1.711 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.3830 (15) Å	Cell parameters from 5360 reflections
b = 7.5819 (15) Å	θ = 3.0–27.8°
c = 10.712 (2) Å	µ = 0.99 mm^−1
α = 96.90 (3)°	T = 293 K
β = 94.62 (3)°	Block, green
γ = 116.00 (3)°	0.3 × 0.3 × 0.3 mm
V = 529.0 (2) Å^3

Data collection

Bruker SMART 1000 CCD area-detector diffractometer	2419 independent reflections
Radiation source: fine-focus sealed tube	2221 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.022
ϕ and ω scan	θmax = 27.5°, θmin = 3.0°
Absorption correction: multi-scan (SADABS; Bruker, 1998)	h = −9→9
Tmin = 0.758, Tmax = 0.766	k = −9→9
5651 measured reflections	l = −13→13

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) = 0.068	H atoms treated by a mixture of independent and constrained refinement
S = 1.14	w = 1/[σ^2(Fo^2) + (0.0235P)^2 + 0.250P] where P = (Fo^2 + 2Fc^2)/3
2419 reflections	(Δ/σ)max < 0.001
184 parameters	Δρmax = 0.25 e Å^−3
0 restraints	Δρmin = −0.27 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
Ni1	0.5000	0.0000	0.5000	0.01921 (10)
O2W	0.7492 (2)	−0.0451 (3)	0.53264 (13)	0.0276 (3)
O3W	0.0848 (2)	0.2902 (2)	0.64256 (16)	0.0335 (3)
N1	0.5324 (2)	0.1275 (2)	0.68998 (14)	0.0241 (3)
O1W	0.6797 (2)	0.2685 (2)	0.45392 (14)	0.0298 (3)
O2	0.1970 (2)	0.3646 (2)	1.40415 (12)	0.0319 (3)
N4	0.4656 (2)	0.2020 (2)	0.87325 (13)	0.0222 (3)
O1	−0.0689 (2)	0.3363 (2)	1.27599 (13)	0.0389 (4)
N2	0.6909 (3)	0.1679 (3)	0.77918 (15)	0.0364 (4)
C1	0.3960 (3)	0.1505 (3)	0.75005 (16)	0.0270 (4)
H1A	0.2701	0.1334	0.7125	0.032*
N3	0.6530 (3)	0.2133 (3)	0.88977 (16)	0.0381 (4)
C8	0.1002 (3)	0.3386 (3)	1.29574 (17)	0.0259 (4)
C6	0.3882 (3)	0.3152 (3)	1.20129 (17)	0.0289 (4)
H6A	0.4567	0.3434	1.2835	0.035*
C4	0.1001 (3)	0.2715 (3)	1.06100 (18)	0.0287 (4)
H4A	−0.0268	0.2696	1.0481	0.034*
C2	0.3748 (3)	0.2411 (3)	0.97907 (16)	0.0222 (4)
C5	0.1985 (3)	0.3081 (3)	1.18314 (16)	0.0232 (4)
C7	0.4783 (3)	0.2814 (3)	1.09967 (17)	0.0284 (4)
H7A	0.6064	0.2857	1.1123	0.034*
C3	0.1874 (3)	0.2377 (3)	0.95800 (17)	0.0294 (4)
H3A	0.1208	0.2129	0.8757	0.035*
H1WB	0.716 (4)	0.371 (4)	0.502 (3)	0.043 (7)*
H2WB	0.741 (4)	−0.138 (4)	0.559 (3)	0.056 (9)*
H1WA	0.762 (4)	0.288 (4)	0.408 (3)	0.059 (9)*
H3WB	0.069 (4)	0.372 (4)	0.675 (3)	0.044 (8)*
H2WA	0.847 (5)	0.048 (5)	0.574 (3)	0.059 (9)*
H3WA	0.118 (5)	0.321 (5)	0.572 (3)	0.074 (10)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ni1	0.02186 (18)	0.02399 (18)	0.01459 (16)	0.01276 (14)	0.00607 (12)	0.00174 (12)
O2W	0.0278 (8)	0.0313 (8)	0.0277 (7)	0.0172 (7)	0.0047 (6)	0.0034 (7)
O3W	0.0370 (8)	0.0400 (9)	0.0309 (8)	0.0228 (7)	0.0111 (7)	0.0070 (7)
N1	0.0278 (8)	0.0300 (8)	0.0179 (7)	0.0161 (7)	0.0066 (6)	0.0026 (6)
O1W	0.0365 (8)	0.0268 (8)	0.0257 (7)	0.0123 (7)	0.0152 (7)	0.0035 (6)
O2	0.0464 (9)	0.0384 (8)	0.0177 (7)	0.0247 (7)	0.0101 (6)	0.0039 (6)
N4	0.0230 (8)	0.0309 (8)	0.0158 (7)	0.0149 (7)	0.0065 (6)	0.0016 (6)
O1	0.0377 (8)	0.0605 (10)	0.0299 (8)	0.0311 (8)	0.0159 (6)	0.0067 (7)
N2	0.0298 (9)	0.0620 (12)	0.0201 (8)	0.0258 (9)	0.0048 (7)	−0.0031 (8)
C1	0.0283 (10)	0.0403 (11)	0.0168 (9)	0.0200 (9)	0.0050 (7)	0.0016 (8)
N3	0.0298 (9)	0.0673 (13)	0.0222 (8)	0.0288 (9)	0.0043 (7)	−0.0023 (8)
C8	0.0350 (11)	0.0245 (9)	0.0214 (9)	0.0151 (8)	0.0118 (8)	0.0036 (7)
C6	0.0326 (11)	0.0414 (11)	0.0163 (9)	0.0202 (9)	0.0055 (8)	0.0031 (8)
C4	0.0253 (10)	0.0427 (12)	0.0226 (9)	0.0197 (9)	0.0060 (8)	0.0029 (8)
C2	0.0272 (9)	0.0261 (9)	0.0158 (8)	0.0136 (8)	0.0086 (7)	0.0028 (7)
C5	0.0282 (10)	0.0258 (9)	0.0177 (8)	0.0135 (8)	0.0087 (7)	0.0031 (7)
C7	0.0265 (10)	0.0445 (12)	0.0198 (9)	0.0212 (9)	0.0054 (8)	0.0042 (8)
C3	0.0297 (10)	0.0463 (12)	0.0160 (9)	0.0213 (10)	0.0040 (7)	0.0025 (8)

Geometric parameters (Å, º)

Ni1—O2W^i	2.0252 (15)	N4—N3	1.344 (2)
Ni1—O2W	2.0252 (15)	N4—C2	1.428 (2)
Ni1—O1W	2.0315 (16)	O1—C8	1.241 (2)
Ni1—O1W^i	2.0315 (16)	N2—N3	1.281 (2)
Ni1—N1^i	2.0927 (15)	C1—H1A	0.9300
Ni1—N1	2.0927 (15)	C8—C5	1.502 (2)
O2W—H2WB	0.77 (3)	C6—C5	1.375 (3)
O2W—H2WA	0.80 (3)	C6—C7	1.376 (3)
O3W—H3WB	0.74 (3)	C6—H6A	0.9300
O3W—H3WA	0.84 (3)	C4—C3	1.375 (3)
N1—C1	1.299 (2)	C4—C5	1.378 (3)
N1—N2	1.346 (2)	C4—H4A	0.9300
O1W—H1WB	0.80 (3)	C2—C3	1.371 (3)
O1W—H1WA	0.79 (3)	C2—C7	1.374 (3)
O2—C8	1.259 (2)	C7—H7A	0.9300
N4—C1	1.323 (2)	C3—H3A	0.9300
O2W^i—Ni1—O2W	180.00 (8)	N3—N4—C2	121.12 (15)
O2W^i—Ni1—O1W	90.81 (7)	N3—N2—N1	110.27 (15)
O2W—Ni1—O1W	89.19 (7)	N1—C1—N4	108.89 (17)
O2W^i—Ni1—O1W^i	89.19 (7)	N1—C1—H1A	125.6
O2W—Ni1—O1W^i	90.81 (7)	N4—C1—H1A	125.6
O1W—Ni1—O1W^i	180.0	N2—N3—N4	106.69 (16)
O2W^i—Ni1—N1^i	92.56 (7)	O1—C8—O2	124.76 (17)
O2W—Ni1—N1^i	87.44 (7)	O1—C8—C5	118.33 (17)
O1W—Ni1—N1^i	88.07 (7)	O2—C8—C5	116.91 (17)
O1W^i—Ni1—N1^i	91.93 (7)	C5—C6—C7	120.97 (18)
O2W^i—Ni1—N1	87.44 (7)	C5—C6—H6A	119.5
O2W—Ni1—N1	92.56 (7)	C7—C6—H6A	119.5
O1W—Ni1—N1	91.93 (7)	C3—C4—C5	120.80 (18)
O1W^i—Ni1—N1	88.07 (7)	C3—C4—H4A	119.6
N1^i—Ni1—N1	180.0	C5—C4—H4A	119.6
Ni1—O2W—H2WB	120 (2)	C3—C2—C7	121.79 (17)
Ni1—O2W—H2WA	115 (2)	C3—C2—N4	119.42 (16)
H2WB—O2W—H2WA	106 (3)	C7—C2—N4	118.79 (16)
H3WB—O3W—H3WA	106 (3)	C6—C5—C4	119.21 (17)
C1—N1—N2	106.30 (15)	C6—C5—C8	119.98 (17)
C1—N1—Ni1	128.19 (13)	C4—C5—C8	120.81 (17)
N2—N1—Ni1	124.50 (12)	C2—C7—C6	118.51 (18)
Ni1—O1W—H1WB	122.5 (18)	C2—C7—H7A	120.7
Ni1—O1W—H1WA	125 (2)	C6—C7—H7A	120.7
H1WB—O1W—H1WA	106 (3)	C2—C3—C4	118.70 (17)
C1—N4—N3	107.85 (15)	C2—C3—H3A	120.6
C1—N4—C2	131.03 (16)	C4—C3—H3A	120.6
O2W^i—Ni1—N1—C1	19.06 (17)	C1—N4—C2—C3	−3.8 (3)
O2W—Ni1—N1—C1	−160.94 (17)	N3—N4—C2—C3	176.84 (18)
O1W—Ni1—N1—C1	109.78 (17)	C1—N4—C2—C7	176.2 (2)
O1W^i—Ni1—N1—C1	−70.22 (17)	N3—N4—C2—C7	−3.1 (3)
N1^i—Ni1—N1—C1	−106 (100)	C7—C6—C5—C4	−1.7 (3)
O2W^i—Ni1—N1—N2	−174.01 (16)	C7—C6—C5—C8	177.90 (18)
O2W—Ni1—N1—N2	5.99 (16)	C3—C4—C5—C6	1.5 (3)
O1W—Ni1—N1—N2	−83.29 (16)	C3—C4—C5—C8	−178.04 (18)
O1W^i—Ni1—N1—N2	96.71 (16)	O1—C8—C5—C6	178.18 (18)
N1^i—Ni1—N1—N2	61 (100)	O2—C8—C5—C6	−1.9 (3)
C1—N1—N2—N3	0.2 (2)	O1—C8—C5—C4	−2.3 (3)
Ni1—N1—N2—N3	−169.14 (14)	O2—C8—C5—C4	177.66 (18)
N2—N1—C1—N4	−0.5 (2)	C3—C2—C7—C6	1.2 (3)
Ni1—N1—C1—N4	168.30 (12)	N4—C2—C7—C6	−178.79 (17)
N3—N4—C1—N1	0.6 (2)	C5—C6—C7—C2	0.3 (3)
C2—N4—C1—N1	−178.81 (17)	C7—C2—C3—C4	−1.4 (3)
N1—N2—N3—N4	0.2 (2)	N4—C2—C3—C4	178.65 (18)
C1—N4—N3—N2	−0.5 (2)	C5—C4—C3—C2	0.0 (3)
C2—N4—N3—N2	179.00 (17)

Symmetry code: (i) −x+1, −y, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1WA···O1^ii	0.79 (3)	1.92 (3)	2.704 (2)	171 (3)
O1W—H1WB···O2^iii	0.80 (3)	1.93 (3)	2.724 (2)	172 (3)
O2W—H2WB···O2^iv	0.77 (3)	2.04 (3)	2.771 (2)	160 (3)
O2W—H2WA···O3W^v	0.80 (3)	1.91 (3)	2.697 (3)	168 (3)
O3W—H3WB···O1^vi	0.74 (3)	2.21 (3)	2.917 (2)	162 (3)
O3W—H3WA···O2^vii	0.84 (3)	1.96 (3)	2.793 (2)	173 (3)

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