Di­aqua­bis­(imidazole-κN)­bis­(nitro­benzoato-κO)­nickel(II)

The title complex, [Ni(C₇H₄NO₄)₂(C₃H₄N₂)₂(H₂O)₂], assumes an octahedral coordination geometry with the Ni atom located on an inversion centre. The overlapped arrangement and the separation of 3.535 (14) Å suggest the existence of π–π stacking between parallel imidazole ligands. Both intramol­ecular and intermolecular hydrogen bonding occur between imidazole, coordinated water molecules and the carboxyl group.

Key indicators

• Single-crystal X-ray study
• T = 295 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.026
• wR factor = 0.068
• Data-to-parameter ratio = 15.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT220_ALERT_2_C Large Non-Solvent    O     Ueq(max)/Ueq(min) ...       3.00 Ratio
PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X)  Ni     -   O5       =       7.23 su
PLAT242_ALERT_2_C Check Low    U(eq) as Compared to Neighbors ....         N3
PLAT250_ALERT_2_C Large U3/U1 ratio for average U(i,j) tensor ....       2.28
PLAT411_ALERT_2_C Short Inter H...H Contact  H6     ..  H6       =       2.10 Ang.

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   5 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
   5 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
   0 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: PROCESS-AUTO (Rigaku, 1998); cell refinement: PROCESS-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2002); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999) and XP (Siemens, 1994).

(I)

Crystal data

[Ni(C7H4NO4)2(C3H4N2)2(H2O)2]	Z = 1
Mr = 563.13	F(000) = 290
Triclinic, P1	Dx = 1.677 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71069 Å
a = 5.644 (2) Å	Cell parameters from 2370 reflections
b = 8.0547 (18) Å	θ = 3.4–27.0°
c = 12.716 (2) Å	µ = 0.94 mm^−1
α = 75.032 (13)°	T = 295 K
β = 87.759 (13)°	Prism, green
γ = 87.079 (12)°	0.27 × 0.18 × 0.17 mm
V = 557.5 (3) Å^3

Data collection

Rigaku R-AXIS RAPID diffractometer	2527 independent reflections
Radiation source: fine-focus sealed tube	2413 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.013
Detector resolution: 10.00 pixels mm^-1	θmax = 27.4°, θmin = 1.7°
ω scans	h = −7→6
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	k = −10→10
Tmin = 0.770, Tmax = 0.855	l = −16→16
5338 measured reflections

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)] = 0.026	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.068	H-atom parameters constrained
S = 1.09	w = 1/[σ^2(Fo^2) + (0.0349P)^2 + 0.2032P] where P = (Fo^2 + 2Fc^2)/3
2527 reflections	(Δ/σ)max < 0.001
169 parameters	Δρmax = 0.32 e Å^−3
0 restraints	Δρmin = −0.23 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
Ni	0.5000	0.5000	0.5000	0.02191 (9)
O1	0.73056 (18)	0.47317 (14)	0.63329 (8)	0.0279 (2)
O2	0.4858 (2)	0.58200 (17)	0.74337 (10)	0.0402 (3)
O3	1.3652 (3)	0.0645 (3)	1.09207 (14)	0.0837 (6)
O4	1.1114 (3)	0.1642 (3)	1.19066 (12)	0.0750 (5)
O5	0.20755 (17)	0.58556 (13)	0.58155 (8)	0.0287 (2)
N1	0.5809 (2)	0.75288 (15)	0.43388 (10)	0.0267 (3)
N2	0.5536 (3)	1.02477 (18)	0.34423 (12)	0.0401 (3)
H2	0.4970	1.1199	0.3036	0.048*
C1	0.4485 (3)	0.8738 (2)	0.36957 (15)	0.0407 (4)
H1	0.3010	0.8565	0.3450	0.049*
C2	0.7641 (3)	1.0012 (2)	0.39372 (16)	0.0427 (4)
H2A	0.8754	1.0836	0.3909	0.051*
C3	0.7803 (3)	0.8332 (2)	0.44836 (15)	0.0410 (4)
H3	0.9083	0.7801	0.4898	0.049*
C4	0.6616 (3)	0.49178 (19)	0.72559 (12)	0.0266 (3)
C5	0.8035 (3)	0.39495 (19)	0.82313 (12)	0.0278 (3)
C6	0.7212 (3)	0.4040 (3)	0.92548 (14)	0.0448 (4)
H6	0.5813	0.4671	0.9321	0.054*
C7	0.8427 (3)	0.3210 (3)	1.01832 (14)	0.0479 (5)
H7	0.7869	0.3277	1.0870	0.058*
C8	1.0481 (3)	0.2285 (2)	1.00559 (13)	0.0351 (3)
C9	1.1339 (3)	0.2132 (2)	0.90548 (13)	0.0373 (4)
H9	1.2728	0.1486	0.8995	0.045*
C10	1.0082 (3)	0.2963 (2)	0.81374 (12)	0.0331 (3)
H10	1.0615	0.2858	0.7455	0.040*
N3	1.1850 (3)	0.1458 (2)	1.10295 (12)	0.0449 (4)
H5B	0.0889	0.5301	0.5952	0.050*
H5A	0.2709	0.5858	0.6428	0.050*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ni	0.02025 (13)	0.02231 (13)	0.02059 (13)	0.00161 (9)	−0.00375 (9)	−0.00085 (9)
O1	0.0259 (5)	0.0335 (5)	0.0223 (5)	0.0015 (4)	−0.0054 (4)	−0.0032 (4)
O2	0.0363 (6)	0.0519 (7)	0.0331 (6)	0.0178 (5)	−0.0105 (5)	−0.0143 (5)
O3	0.0650 (11)	0.1203 (16)	0.0499 (9)	0.0451 (11)	−0.0211 (8)	0.0007 (10)
O4	0.0802 (12)	0.1059 (14)	0.0306 (7)	0.0215 (10)	−0.0193 (7)	−0.0051 (8)
O5	0.0229 (5)	0.0321 (5)	0.0287 (5)	0.0023 (4)	−0.0033 (4)	−0.0039 (4)
N1	0.0265 (6)	0.0244 (6)	0.0267 (6)	0.0015 (5)	−0.0038 (5)	−0.0019 (5)
N2	0.0467 (8)	0.0257 (6)	0.0412 (8)	0.0039 (6)	−0.0096 (6)	0.0037 (6)
C1	0.0344 (8)	0.0322 (8)	0.0488 (10)	0.0021 (7)	−0.0137 (7)	0.0028 (7)
C2	0.0445 (9)	0.0311 (8)	0.0500 (10)	−0.0078 (7)	−0.0104 (8)	−0.0035 (7)
C3	0.0380 (9)	0.0315 (8)	0.0497 (10)	−0.0016 (7)	−0.0185 (8)	−0.0010 (7)
C4	0.0261 (7)	0.0273 (7)	0.0255 (7)	0.0002 (5)	−0.0067 (5)	−0.0043 (5)
C5	0.0274 (7)	0.0307 (7)	0.0234 (6)	0.0015 (6)	−0.0050 (5)	−0.0033 (5)
C6	0.0394 (9)	0.0661 (12)	0.0275 (8)	0.0205 (8)	−0.0072 (7)	−0.0128 (8)
C7	0.0468 (10)	0.0709 (13)	0.0232 (7)	0.0139 (9)	−0.0056 (7)	−0.0094 (8)
C8	0.0352 (8)	0.0378 (8)	0.0271 (7)	−0.0007 (6)	−0.0111 (6)	0.0023 (6)
C9	0.0331 (8)	0.0395 (9)	0.0333 (8)	0.0096 (7)	−0.0052 (6)	−0.0004 (7)
C10	0.0347 (8)	0.0367 (8)	0.0244 (7)	0.0064 (6)	−0.0023 (6)	−0.0025 (6)
N3	0.0448 (8)	0.0500 (9)	0.0322 (7)	−0.0012 (7)	−0.0134 (6)	0.0048 (6)

Geometric parameters (Å, º)

Ni—N1	2.0602 (13)	C2—C3	1.352 (2)
Ni—O5	2.0961 (11)	C2—H2A	0.9300
Ni—O1	2.1371 (10)	C3—H3	0.9300
O1—C4	1.2651 (18)	C4—C5	1.5173 (19)
O2—C4	1.2480 (19)	C5—C6	1.383 (2)
O3—N3	1.204 (2)	C5—C10	1.387 (2)
O4—N3	1.217 (2)	C6—C7	1.385 (2)
O5—H5B	0.812	C6—H6	0.9300
O5—H5A	0.871	C7—C8	1.373 (3)
N1—C1	1.3187 (19)	C7—H7	0.9300
N1—C3	1.368 (2)	C8—C9	1.377 (2)
N2—C1	1.338 (2)	C8—N3	1.4731 (19)
N2—C2	1.348 (2)	C9—C10	1.388 (2)
N2—H2	0.8600	C9—H9	0.9300
C1—H1	0.9300	C10—H10	0.9300
N1—Ni—O5	88.78 (5)	O2—C4—C5	117.20 (13)
N1—Ni—O1	92.80 (5)	O1—C4—C5	117.22 (13)
O5—Ni—O1	93.68 (4)	C6—C5—C10	119.15 (14)
C4—O1—Ni	123.66 (9)	C6—C5—C4	118.04 (14)
Ni—O5—H5B	120.52	C10—C5—C4	122.79 (13)
Ni—O5—H5A	100.58	C5—C6—C7	121.42 (16)
H5B—O5—H5A	108.23	C5—C6—H6	119.3
C1—N1—C3	104.83 (13)	C7—C6—H6	119.3
C1—N1—Ni	127.24 (11)	C8—C7—C6	117.76 (16)
C3—N1—Ni	127.92 (10)	C8—C7—H7	121.1
C1—N2—C2	107.83 (14)	C6—C7—H7	121.1
C1—N2—H2	126.1	C7—C8—C9	122.76 (14)
C2—N2—H2	126.1	C7—C8—N3	118.47 (15)
N1—C1—N2	111.27 (15)	C9—C8—N3	118.76 (15)
N1—C1—H1	124.4	C8—C9—C10	118.44 (15)
N2—C1—H1	124.4	C8—C9—H9	120.8
N2—C2—C3	105.94 (15)	C10—C9—H9	120.8
N2—C2—H2A	127.0	C5—C10—C9	120.42 (15)
C3—C2—H2A	127.0	C5—C10—H10	119.8
C2—C3—N1	110.13 (15)	C9—C10—H10	119.8
C2—C3—H3	124.9	O3—N3—O4	123.06 (16)
N1—C3—H3	124.9	O3—N3—C8	118.64 (16)
O2—C4—O1	125.58 (13)	O4—N3—C8	118.30 (16)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2···O2^i	0.86	2.33	3.074 (2)	146
O5—H5A···O2	0.87	1.79	2.6304 (18)	162
O5—H5B···O1^ii	0.81	2.11	2.8813 (17)	159
C3—H3···O5^iii	0.93	2.37	3.278 (2)	166

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