Bis[2-(1H-benzimidazol-2-yl-κN³)-4,6-dibromo­phenolato-κO]nickel(II)

The title compound, [Ni(C₁₃H₇Br₂N₂O)₂], an Ni^II complex of the Schiff base 2-(3,5-dibromo-2-hydroxy­phen­yl)benz­imid­azole, was synthesized by the reaction of 3,5-dibromo­salicylaldehyde and 1,2-phenyl­enediamine. The mol­ecule resides on a twofold rotation axis. The Ni^II atom exists in a distorted tetra­hedral geometry and is coordinated by one O and one N atom from each of two 2-(3,5-dibromo-2-hydroxy­phen­yl)benzimidazole ligands. The crystal structure is stabilized by N—H...Br and N—H...O hydrogen bonds, which link the mol­ecules into a chain along the b axis.

Key indicators

• Single-crystal X-ray study
• T = 292 K
• Mean [sigma](C-C) = 0.013 Å
• R factor = 0.065
• wR factor = 0.180
• Data-to-parameter ratio = 14.6

checkCIF/PLATON results

No syntax errors found



Alert level C
RINTA01_ALERT_3_C  The value of Rint is greater than 0.10
            Rint given   0.127
PLAT020_ALERT_3_C The value of Rint is greater than 0.10 .........       0.13
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.74
PLAT341_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ...         13
PLAT431_ALERT_2_C Short Inter HL..A Contact  Br2    ..  Br2     ..       3.53 Ang.
PLAT731_ALERT_1_C Bond    Calc     0.86(7), Rep     0.86(3) ......       2.33 su-Ra
              N2   -H2A     1.555   1.555
PLAT735_ALERT_1_C D-H     Calc     0.86(7), Rep     0.86(3) ......       2.33 su-Ra
              N2   -H2A     1.555   1.555
PLAT735_ALERT_1_C D-H     Calc     0.86(7), Rep     0.86(3) ......       2.33 su-Ra
              N2   -H2A     1.555   1.555

Alert level G
ABSTM02_ALERT_3_G  When printed, the submitted absorption T values will be
            replaced by the scaled T values. Since the ratio of scaled T's
            is identical to the ratio of reported T values, the scaling
            does not imply a change to the absorption corrections used in
            the study.
            Ratio of Tmax expected/reported      0.737
            Tmax scaled      0.247 Tmin scaled      0.168
PLAT794_ALERT_5_G Check Predicted Bond Valency for Ni1         (2)       1.82
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          1

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

   3 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
   5 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Comment

Crystal structure and properties of 1,2-N,N-disallicydene-phenylamineato nickel(II) has been reported (Wang et al., 2003). We report here the synthesis and crystal structure of bis[2-(3,5-dibromo-2-hydroxyphenyl) benzimidazole]nickel(II).

The asymmetric unit of the title compound consists of a half-molecule, with the Ni^II atom lying on a crystallographic twofold axis; the other half of the molecule is generated by the twofold axis (Fig. 1). The Ni^II atom exists in a distorted tetrahedral geometry (Table 1) and is coordinated by the O and one N atom each from two 3,5-dibromo-2-hydroxyphenyl benzimidazole ligands.

The crystal structure is stabilized by N—H···Br and N—H···O type hydrogen bonds which link the molecules into a chain along the b axis.

Related literature

For ligand synthesis, see: Elzbieta et al. (1964). For a related structure, see: Wang et al. (2003).

S2. Experimental

3,5-Dibromosalicylaldehyde was prepared according to the literature method (Elzbieta et al., 1964). To a solution of 1,2-phenylenediamine (1 g) in pyridine (30 ml), one mole equivalent of 3,5-dibromosalicylaldehyde in pyridine (30 ml) was added slowly under continuous stirring and refluxed for 1 h. Then Ni(Ac)₂ (10 mmol) in DMF (10 ml) was added and the solution were refluxed for 1 h. The hot solution was filtered and allowed to stand at room temperature undisturbed for about three weeks, resulting in yellow crystals.

S3. Refinement

The N-bound H atom was located in a difference map and refined with a N—H distance restraint of 0.86 (2) Å. C-bound H atoms were placed at calculated positions and refined using a riding model, with C—H = 0.93 Å and U_iso(H) = 1.2U_eq(C).

Computing details

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1997); software used to prepare material for publication: SHELXL97.

Figures

Fig. 1. The molecular structure of the title compound, showing labelling of the non-H atoms and 20% probability displacement ellipsoids. Atoms labelled with the suffixe a are generated by the symmetry operation (2 - x, 1/2 - y, z).

Bis[2-(1H-benzimidazol-2-yl-κN³)-4,6-dibromophenolato-κO]nickel(II)

Crystal data

[Ni(C13H7Br2N2O)2]	Dx = 2.045 Mg m^−3
Mr = 792.76	Mo Kα radiation, λ = 0.71073 Å
Tetragonal, I41/a	Cell parameters from 1302 reflections
Hall symbol: -I 4ad	θ = 2.4–16.7°
a = 12.4177 (14) Å	µ = 7.00 mm^−1
c = 33.389 (6) Å	T = 292 K
V = 5148.6 (12) Å^3	Block, yellow
Z = 8	0.30 × 0.20 × 0.20 mm
F(000) = 3056

Data collection

Bruker SMART CCD area-detector diffractometer	2510 independent reflections
Radiation source: fine-focus sealed tube	1324 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.127
φ and ω scans	θmax = 26.0°, θmin = 2.5°
Absorption correction: multi-scan (SADABS; Bruker, 2000)	h = −15→9
Tmin = 0.228, Tmax = 0.335	k = −15→14
13205 measured reflections	l = −41→41

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)] = 0.065	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.180	H atoms treated by a mixture of independent and constrained refinement
S = 0.95	w = 1/[σ^2(Fo^2) + (0.0739P)^2] where P = (Fo^2 + 2Fc^2)/3
2510 reflections	(Δ/σ)max = 0.001
172 parameters	Δρmax = 0.90 e Å^−3
1 restraint	Δρmin = −0.48 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	1.0000	0.2500	0.00587 (4)	0.0486 (4)
Br1	0.69106 (11)	0.20197 (9)	−0.08406 (3)	0.0957 (5)
Br2	0.54458 (11)	0.61501 (10)	−0.04228 (4)	0.1101 (6)
N1	0.9689 (5)	0.3813 (5)	0.03615 (18)	0.0519 (17)
C1	0.7060 (8)	0.3281 (7)	−0.0523 (2)	0.068 (3)
C2	0.6348 (8)	0.4068 (8)	−0.0575 (3)	0.069 (3)
H2	0.5784	0.3992	−0.0756	0.083*
C3	0.6467 (8)	0.5014 (8)	−0.0351 (3)	0.073 (3)
C4	0.7292 (8)	0.5120 (7)	−0.0096 (3)	0.066 (2)
H4	0.7366	0.5759	0.0046	0.080*
C5	0.8040 (7)	0.4306 (6)	−0.0038 (2)	0.054 (2)
C6	0.7982 (7)	0.3334 (7)	−0.0261 (2)	0.054 (2)
C7	0.8901 (6)	0.4497 (6)	0.0259 (2)	0.0455 (18)
C8	1.0267 (6)	0.4270 (6)	0.0663 (2)	0.0498 (19)
C9	1.1152 (8)	0.3939 (7)	0.0879 (3)	0.073 (3)
H9	1.1459	0.3267	0.0833	0.087*
C10	1.1577 (9)	0.4622 (9)	0.1164 (3)	0.085 (3)
H10	1.2195	0.4418	0.1302	0.102*
C11	1.1105 (10)	0.5600 (9)	0.1249 (3)	0.094 (3)
H11	1.1388	0.6018	0.1454	0.112*
C12	1.0223 (9)	0.5978 (8)	0.1038 (3)	0.082 (3)
H12	0.9906	0.6641	0.1092	0.098*
C13	0.9851 (7)	0.5306 (7)	0.0744 (2)	0.057 (2)
O1	0.8626 (5)	0.2535 (4)	−0.02442 (16)	0.0602 (15)
N2	0.8956 (6)	0.5388 (6)	0.0481 (2)	0.0577 (18)
H2A	0.867 (8)	0.601 (5)	0.052 (3)	0.11 (4)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ni1	0.0612 (10)	0.0366 (8)	0.0480 (7)	0.0184 (7)	0.000	0.000
Br1	0.1218 (10)	0.0805 (8)	0.0850 (7)	0.0258 (7)	−0.0409 (7)	−0.0212 (6)
Br2	0.1109 (10)	0.0997 (9)	0.1197 (10)	0.0604 (8)	−0.0217 (7)	0.0026 (7)
N1	0.066 (4)	0.033 (3)	0.056 (4)	0.014 (3)	0.003 (3)	−0.001 (3)
C1	0.085 (7)	0.064 (6)	0.056 (5)	0.021 (5)	−0.005 (5)	−0.003 (4)
C2	0.073 (6)	0.073 (7)	0.061 (5)	0.020 (5)	−0.021 (4)	−0.004 (5)
C3	0.082 (7)	0.064 (6)	0.072 (6)	0.041 (5)	−0.003 (5)	0.012 (5)
C4	0.081 (7)	0.058 (6)	0.060 (5)	0.027 (5)	0.001 (5)	0.005 (4)
C5	0.067 (6)	0.051 (5)	0.042 (4)	0.013 (4)	0.000 (4)	−0.001 (4)
C6	0.066 (6)	0.051 (5)	0.046 (4)	0.013 (4)	0.001 (4)	0.009 (4)
C7	0.059 (5)	0.031 (4)	0.047 (4)	0.001 (4)	0.017 (4)	0.009 (3)
C8	0.045 (5)	0.055 (5)	0.049 (4)	0.006 (4)	0.003 (4)	0.010 (4)
C9	0.091 (7)	0.047 (5)	0.080 (6)	−0.004 (5)	−0.007 (5)	0.007 (5)
C10	0.098 (8)	0.098 (9)	0.060 (6)	−0.018 (7)	−0.020 (5)	0.004 (5)
C11	0.118 (10)	0.073 (8)	0.090 (7)	0.002 (7)	−0.015 (7)	−0.016 (6)
C12	0.099 (8)	0.057 (6)	0.090 (7)	0.001 (6)	−0.004 (6)	−0.021 (5)
C13	0.070 (6)	0.044 (5)	0.057 (5)	0.003 (4)	0.010 (4)	−0.001 (4)
O1	0.080 (4)	0.038 (3)	0.062 (3)	0.016 (3)	−0.009 (3)	−0.005 (3)
N2	0.067 (5)	0.041 (4)	0.065 (4)	0.015 (4)	0.006 (4)	−0.004 (3)

Geometric parameters (Å, º)

Ni1—N1	1.957 (6)	C5—C7	1.480 (11)
Ni1—N1^i	1.957 (6)	C6—O1	1.276 (9)
Ni1—O1	1.984 (6)	C7—N2	1.333 (10)
Ni1—O1^i	1.984 (6)	C8—C9	1.378 (11)
Br1—C1	1.902 (9)	C8—C13	1.413 (11)
Br2—C3	1.913 (8)	C9—C10	1.379 (12)
N1—C7	1.340 (9)	C9—H9	0.93
N1—C8	1.359 (10)	C10—C11	1.378 (14)
C1—C2	1.329 (11)	C10—H10	0.93
C1—C6	1.442 (12)	C11—C12	1.385 (15)
C2—C3	1.400 (12)	C11—H11	0.93
C2—H2	0.93	C12—C13	1.367 (12)
C3—C4	1.338 (13)	C12—H12	0.93
C4—C5	1.385 (11)	C13—N2	1.421 (11)
C4—H4	0.93	N2—H2A	0.86 (3)
C5—C6	1.419 (11)
N1—Ni1—N1^i	117.8 (4)	C5—C6—C1	113.3 (7)
N1—Ni1—O1	94.4 (2)	N2—C7—N1	110.3 (7)
N1^i—Ni1—O1	116.8 (2)	N2—C7—C5	122.9 (7)
N1—Ni1—O1^i	116.8 (2)	N1—C7—C5	126.7 (7)
N1^i—Ni1—O1^i	94.4 (2)	N1—C8—C9	133.1 (8)
O1—Ni1—O1^i	118.7 (3)	N1—C8—C13	109.3 (7)
C7—N1—C8	108.0 (6)	C9—C8—C13	117.5 (8)
C7—N1—Ni1	122.7 (5)	C8—C9—C10	118.9 (9)
C8—N1—Ni1	128.8 (5)	C8—C9—H9	120.6
C2—C1—C6	125.0 (8)	C10—C9—H9	120.6
C2—C1—Br1	117.9 (7)	C11—C10—C9	121.4 (10)
C6—C1—Br1	117.0 (6)	C11—C10—H10	119.3
C1—C2—C3	118.5 (8)	C9—C10—H10	119.3
C1—C2—H2	120.8	C10—C11—C12	122.1 (10)
C3—C2—H2	120.8	C10—C11—H11	119.0
C4—C3—C2	120.2 (8)	C12—C11—H11	119.0
C4—C3—Br2	121.0 (7)	C13—C12—C11	115.1 (9)
C2—C3—Br2	118.8 (7)	C13—C12—H12	122.5
C3—C4—C5	122.0 (8)	C11—C12—H12	122.5
C3—C4—H4	119.0	C12—C13—C8	124.9 (9)
C5—C4—H4	119.0	C12—C13—N2	131.6 (9)
C4—C5—C6	120.9 (8)	C8—C13—N2	103.4 (7)
C4—C5—C7	117.5 (7)	C6—O1—Ni1	125.3 (5)
C6—C5—C7	121.6 (7)	C7—N2—C13	108.9 (7)
O1—C6—C5	127.4 (8)	C7—N2—H2A	145 (8)
O1—C6—C1	119.3 (7)	C13—N2—H2A	106 (8)
N1^i—Ni1—N1—C7	−137.8 (6)	C6—C5—C7—N2	−177.9 (7)
O1—Ni1—N1—C7	−14.4 (6)	C4—C5—C7—N1	179.3 (7)
O1^i—Ni1—N1—C7	110.9 (6)	C6—C5—C7—N1	−1.4 (11)
N1^i—Ni1—N1—C8	51.4 (6)	C7—N1—C8—C9	−179.7 (9)
O1—Ni1—N1—C8	174.9 (6)	Ni1—N1—C8—C9	−7.9 (13)
O1^i—Ni1—N1—C8	−59.8 (7)	C7—N1—C8—C13	−2.3 (8)
C6—C1—C2—C3	−2.4 (15)	Ni1—N1—C8—C13	169.5 (5)
Br1—C1—C2—C3	−178.2 (7)	N1—C8—C9—C10	178.0 (9)
C1—C2—C3—C4	1.1 (14)	C13—C8—C9—C10	0.8 (12)
C1—C2—C3—Br2	−179.9 (7)	C8—C9—C10—C11	3.0 (15)
C2—C3—C4—C5	−1.2 (14)	C9—C10—C11—C12	−3.9 (17)
Br2—C3—C4—C5	179.8 (6)	C10—C11—C12—C13	0.8 (16)
C3—C4—C5—C6	2.5 (13)	C11—C12—C13—C8	3.3 (15)
C3—C4—C5—C7	−178.2 (8)	C11—C12—C13—N2	177.0 (9)
C4—C5—C6—O1	178.4 (8)	N1—C8—C13—C12	178.1 (8)
C7—C5—C6—O1	−0.9 (13)	C9—C8—C13—C12	−4.1 (13)
C4—C5—C6—C1	−3.3 (11)	N1—C8—C13—N2	2.9 (8)
C7—C5—C6—C1	177.4 (7)	C9—C8—C13—N2	−179.3 (7)
C2—C1—C6—O1	−178.1 (9)	C5—C6—O1—Ni1	−7.4 (11)
Br1—C1—C6—O1	−2.3 (10)	C1—C6—O1—Ni1	174.4 (6)
C2—C1—C6—C5	3.4 (13)	N1—Ni1—O1—C6	12.9 (6)
Br1—C1—C6—C5	179.2 (6)	N1^i—Ni1—O1—C6	137.1 (6)
C8—N1—C7—N2	0.7 (8)	O1^i—Ni1—O1—C6	−111.0 (6)
Ni1—N1—C7—N2	−171.7 (5)	N1—C7—N2—C13	1.1 (8)
C8—N1—C7—C5	−176.1 (7)	C5—C7—N2—C13	178.1 (7)
Ni1—N1—C7—C5	11.5 (10)	C12—C13—N2—C7	−177.1 (9)
C4—C5—C7—N2	2.8 (11)	C8—C13—N2—C7	−2.4 (8)

Symmetry code: (i) −x+2, −y+1/2, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2A···Br1^ii	0.86 (3)	2.74 (7)	3.464 (7)	143 (9)
N2—H2A···O1^ii	0.86 (3)	2.11 (8)	2.811 (9)	138 (9)

Symmetry code: (ii) x, y+1/2, −z.