Bis{2-[6-(1H-benzimidazol-2-yl-κN ³)-2-pyridyl-κN]benzimidazolato-κN}manganese(II)

Abstract

In the title compound, [Mn(C₁₉H₁₂N₅)₂], each Mn^II atom lies on a position of site symmetry 222 and has a distorted octa­hedral coordination geometry made up from six N atoms of two tridentate 2-[6-(1H-benzimidazol-2-yl)-2-pyrid­yl]benz­imidazolate ligands. The complex mol­ecules are linked into layers parallel to (001) by N—H⋯N hydrogen bonds, with the H atoms disordered over four symmetry-equivalent non-coordinated N atoms.

Related literature

For a previous report of this complex, see: Shi et al. (2003 ▶). For other comparable transition-metal complexes, see: Harvey et al. (2003 ▶); Wang et al. (1994 ▶); Yue et al. (2006 ▶); Zhang et al. (2007 ▶).

Experimental

Crystal data

• [Mn(C₁₉H₁₂N₅)₂]

• M _r = 675.61

• Tetragonal,

• a = 10.1225 (14) Å

• c = 15.865 (3) Å

• V = 1625.6 (5) ų

• Z = 2

• Mo Kα radiation

• μ = 0.45 mm⁻¹

• T = 298 K

• 0.45 × 0.44 × 0.31 mm

Data collection

• Bruker SMART 2K CCD diffractometer

• Absorption correction: none

• 6803 measured reflections

• 1599 independent reflections

• 1226 reflections with I > 2σ(I)

• R _int = 0.040

Refinement

• R[F ² > 2σ(F ²)] = 0.035

• wR(F ²) = 0.095

• S = 1.04

• 1599 reflections

• 113 parameters

• H-atom parameters constrained

• Δρ_max = 0.18 e Å⁻³

• Δρ_min = −0.21 e Å⁻³

• Absolute structure: Flack (1983 ▶), 701 Friedel pairs

• Flack parameter: 0.00 (1)

Data collection: SMART (Bruker, 2003 ▶); cell refinement: SAINT (Bruker, 2003 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N3—H1⋯N3i	0.91	1.89	2.736 (4)	154

Symmetry code: (i) .

supplementary crystallographic information

Comment

The 2,6-bis(1H-benzimidazol-2-yl)pyridine ligand is known to form complexes with various transition metal atoms (Harvey et al., 2003; Wang et al., 1994; Yue et al., 2006; Zhang et al., 2007). The title compound, containing Mn^II, has been reported previously (Shi et al., 2003), with closely comparable cell parameters but refined in space group Pn. Atomic coordinates were not reported and they are not available in the Cambridge Structural Database. However, diagrams of the structure in the paper of Shi et al. (2003) suggest it to be closely comparable to the current reported structure, and it is probable that the previous refinement in Pn is an instance of "missed symmetry".

Experimental

Manganese nitrate hexahydrate (0.144 g, 0.5 mmol) and 2,6-bis(1H-benzimidazol-2-yl)pyridine (0.1536 g, 1 mmol) were dissolved in ethanol (8 ml). The solution was placed in a 15 ml Teflon-lined stainless steel bomb and heated at 423 K for 96 h. The cooled mixture yielded red block-shaped crystals in about 41% yield. The crystals were washed with ethanol and dried in air.

Refinement

All H atoms were positioned geometrically (C—H = 0.93 Å, N—H = 0.91 Å) and refined as riding with U_iso(H) = 1.2 U_eq(C or N). The site occupancy of H1 was constrained to 0.5 so that it sums to a total of 2 H atoms disordered over the four symmetry-equivalent N3 atoms.

Figures

Fig. 1.

Molecular structure showing 30% probability displacement ellipsoids. H atoms are omitted. Symmetry codes: (A) -x + 2, -y, z; (B) -y + 1, -x + 1, -z; (C) y + 1, x - 1, -z.

Crystal data

[Mn(C19H12N5)2]	Dx = 1.380 Mg m−3
Mr = 675.61	Mo Kα radiation, λ = 0.71073 Å
Tetragonal, P4n2	Cell parameters from 6803 reflections
Hall symbol: P -4 -2n	θ = 2.4–26.0°
a = 10.1225 (14) Å	µ = 0.45 mm−1
c = 15.865 (3) Å	T = 298 K
V = 1625.6 (5) Å3	Block, red
Z = 2	0.45 × 0.44 × 0.31 mm
F(000) = 694

Data collection

Bruker SMART 2K CCD diffractometer	1226 reflections with I > 2<s(I)
Radiation source: fine-focus sealed tube	Rint = 0.040
graphite	θmax = 26.0°, θmin = 2.4°
φ and ω scans	h = −10→12
6803 measured reflections	k = −12→11
1599 independent reflections	l = −19→12

Refinement

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.035	H-atom parameters constrained
wR(F2) = 0.095	w = 1/[σ2(Fo2) + (0.0482P)2 + 0.3361P] where P = (Fo2 + 2Fc2)/3
S = 1.03	(Δ/σ)max < 0.001
1599 reflections	Δρmax = 0.18 e Å−3
113 parameters	Δρmin = −0.21 e Å−3
0 restraints	Absolute structure: Flack (1983), 701 Friedel pairs
Primary atom site location: structure-invariant direct methods	Flack parameter: 0.00 (1)

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	Occ. (<1)
Mn1	0.5000	0.0000	0.2500	0.0372 (2)
C1	0.3191 (3)	0.1985 (3)	0.12293 (17)	0.0379 (6)
C2	0.2023 (3)	0.1312 (3)	0.1090 (2)	0.0542 (9)
H2	0.1913	0.0448	0.1279	0.065*
C3	0.1031 (4)	0.1952 (4)	0.0668 (3)	0.0626 (10)
H3	0.0234	0.1520	0.0575	0.075*
C4	0.1195 (3)	0.3226 (4)	0.0376 (2)	0.0625 (10)
H4	0.0511	0.3624	0.0078	0.075*
C5	0.2336 (3)	0.3919 (3)	0.0513 (2)	0.0540 (9)
H5	0.2432	0.4782	0.0321	0.065*
C6	0.3348 (3)	0.3286 (3)	0.09494 (19)	0.0406 (7)
C7	0.5083 (3)	0.2688 (3)	0.16267 (18)	0.0366 (7)
C8	0.6350 (3)	0.2666 (3)	0.2067 (2)	0.0471 (8)
C9	0.7292 (4)	0.3650 (4)	0.2072 (3)	0.0915 (16)
H9	0.7147	0.4441	0.1789	0.110*
C10	0.8439 (3)	0.3439 (3)	0.2500	0.128 (3)
H10	0.9089	0.4089	0.2500	0.154*
N1	0.65540 (18)	0.15540 (18)	0.2500	0.0381 (7)
N2	0.4325 (2)	0.1611 (2)	0.16468 (16)	0.0388 (6)
N3	0.4560 (2)	0.3722 (2)	0.12179 (17)	0.0437 (6)
H1	0.5082	0.4448	0.1157	0.066*	0.50

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Mn1	0.0277 (3)	0.0277 (3)	0.0560 (5)	−0.0078 (3)	0.000	0.000
C1	0.0366 (16)	0.0338 (16)	0.0435 (15)	−0.0021 (11)	−0.0031 (14)	−0.0071 (14)
C2	0.0514 (19)	0.0429 (18)	0.068 (2)	−0.0116 (14)	−0.0116 (18)	−0.0014 (17)
C3	0.049 (2)	0.056 (2)	0.083 (3)	−0.0112 (17)	−0.016 (2)	−0.003 (2)
C4	0.0494 (19)	0.062 (2)	0.076 (3)	0.0047 (18)	−0.0231 (18)	0.0033 (19)
C5	0.053 (2)	0.0375 (17)	0.071 (2)	0.0038 (15)	−0.0036 (17)	0.0058 (18)
C6	0.0381 (16)	0.0316 (16)	0.0520 (18)	−0.0011 (12)	−0.0007 (14)	−0.0043 (14)
C7	0.0358 (15)	0.0240 (13)	0.0501 (18)	−0.0011 (11)	0.0004 (15)	0.0004 (12)
C8	0.0367 (16)	0.0352 (16)	0.069 (2)	−0.0057 (12)	−0.0053 (16)	0.0089 (15)
C9	0.066 (2)	0.051 (2)	0.158 (4)	−0.0324 (18)	−0.046 (3)	0.047 (2)
C10	0.078 (3)	0.078 (3)	0.229 (8)	−0.058 (3)	−0.083 (5)	0.083 (5)
N1	0.0292 (9)	0.0292 (9)	0.0559 (19)	−0.0071 (11)	0.0007 (15)	−0.0007 (15)
N2	0.0347 (13)	0.0285 (11)	0.0531 (15)	−0.0063 (10)	−0.0047 (11)	−0.0010 (11)
N3	0.0402 (13)	0.0285 (12)	0.0623 (16)	−0.0045 (10)	−0.0046 (13)	0.0033 (13)

Geometric parameters (Å, °)

Mn1—N1i	2.225 (3)	C5—C6	1.393 (4)
Mn1—N1	2.225 (3)	C5—H5	0.930
Mn1—N2ii	2.226 (2)	C6—N3	1.372 (4)
Mn1—N2i	2.226 (2)	C7—N2	1.333 (3)
Mn1—N2	2.226 (2)	C7—N3	1.341 (4)
Mn1—N2iii	2.226 (2)	C7—C8	1.461 (4)
C1—N2	1.378 (3)	C8—N1	1.334 (3)
C1—C2	1.382 (4)	C8—C9	1.379 (4)
C1—C6	1.399 (4)	C9—C10	1.362 (4)
C2—C3	1.370 (5)	C9—H9	0.930
C2—H2	0.930	C10—C9iii	1.362 (4)
C3—C4	1.380 (5)	C10—H10	0.930
C3—H3	0.930	N1—C8iii	1.334 (3)
C4—C5	1.369 (5)	N3—H1	0.910
C4—H4	0.930
N1i—Mn1—N1	180.00 (13)	C4—C5—C6	117.7 (3)
N1i—Mn1—N2ii	72.49 (5)	C4—C5—H5	121.2
N1—Mn1—N2ii	107.51 (5)	C6—C5—H5	121.2
N1i—Mn1—N2i	72.49 (5)	N3—C6—C5	131.7 (3)
N1—Mn1—N2i	107.51 (5)	N3—C6—C1	107.8 (3)
N2ii—Mn1—N2i	144.99 (11)	C5—C6—C1	120.5 (3)
N1i—Mn1—N2	107.51 (5)	N2—C7—N3	115.0 (2)
N1—Mn1—N2	72.49 (5)	N2—C7—C8	118.8 (2)
N2ii—Mn1—N2	85.43 (12)	N3—C7—C8	126.1 (2)
N2i—Mn1—N2	105.11 (12)	N1—C8—C9	120.0 (3)
N1i—Mn1—N2iii	107.51 (5)	N1—C8—C7	113.2 (2)
N1—Mn1—N2iii	72.49 (5)	C9—C8—C7	126.8 (3)
N2ii—Mn1—N2iii	105.11 (12)	C10—C9—C8	118.6 (4)
N2i—Mn1—N2iii	85.43 (12)	C10—C9—H9	120.7
N2—Mn1—N2iii	144.99 (11)	C8—C9—H9	120.7
N2—C1—C2	130.8 (3)	C9—C10—C9iii	121.0 (4)
N2—C1—C6	108.5 (2)	C9—C10—H10	119.5
C2—C1—C6	120.7 (3)	C9iii—C10—H10	119.5
C3—C2—C1	118.1 (3)	C8—N1—C8iii	121.7 (3)
C3—C2—H2	120.9	C8—N1—Mn1	119.15 (16)
C1—C2—H2	120.9	C8iii—N1—Mn1	119.15 (16)
C2—C3—C4	121.2 (3)	C7—N2—C1	104.0 (2)
C2—C3—H3	119.4	C7—N2—Mn1	115.90 (18)
C4—C3—H3	119.4	C1—N2—Mn1	138.51 (18)
C5—C4—C3	121.8 (3)	C7—N3—C6	104.6 (2)
C5—C4—H4	119.1	C7—N3—H1	116.9
C3—C4—H4	119.1	C6—N3—H1	138.2

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

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
N3—H1···N3iv	0.91	1.89	2.736 (4)	154

Symmetry codes: (iv) −x+1, −y+1, z.