catena-Poly[[diaqua­dibromidoman­ganese(III)]-μ-pyridine-2-carboxyl­ato]

Abstract

The asymmetric unit of the title compound, [MnBr₂(C₆H₄NO₂)(H₂O)₂]_n, contains one monomeric unit of the neutral linear coordination polymer. The Mn³⁺ ions are bridged by anionic pyridine-2-carboxyl­ate (pic) ligands, thereby forming a chain-like structure along the c axis, and are six-coordinated in a distorted octa­hedral environment by two O atoms of the two different carboxyl­ate groups, two O atoms of two water mol­ecules and two Br atoms. The complex displays inter­molecular O—H⋯Br, O—H⋯N, O—H⋯O, C—H⋯O and C—H⋯Br hydrogen bonding. There may also be inter­molecular π–π inter­actions between adjacent pyridine rings, with a centroid–centroid distance of 3.993 (8) Å.

Related literature

For the synthesis and structure of [Mn(pic)₃], see: Figgis et al. (1978 ▶); Yamaguchi & Sawyer (1985 ▶); Li et al. (2000 ▶). For the synthesis and structure of [Mn(pic)₂(H₂O)₂], see: Okabe & Koizumi (1998 ▶); Barandika et al. (1999 ▶). For details of mono-, di- and polynuclear Mn(II, III, IV)–pic complexes, see: Huang et al. (2004 ▶). For the synthesis and structure of the anionic Mn(II)–pic polymer, {[MnBr₂(pic)(H₂O)]⁻}_n, see: Kim et al. (2009 ▶).

Experimental

Crystal data

• [MnBr₂(C₆H₄NO₂)(H₂O)₂]

• M _r = 372.89

• Monoclinic,

• a = 10.290 (3) Å

• b = 13.814 (4) Å

• c = 7.978 (3) Å

• β = 109.810 (6)°

• V = 1066.9 (6) ų

• Z = 4

• Mo Kα radiation

• μ = 8.71 mm⁻¹

• T = 223 K

• 0.25 × 0.23 × 0.10 mm

Data collection

• Bruker SMART 1000 CCD diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2000 ▶) T _min = 0.133, T _max = 0.418

• 6572 measured reflections

• 2168 independent reflections

• 1510 reflections with I > 2σ(I)

• R _int = 0.060

Refinement

• R[F ² > 2σ(F ²)] = 0.070

• wR(F ²) = 0.248

• S = 1.14

• 2168 reflections

• 127 parameters

• H-atom parameters constrained

• Δρ_max = 2.85 e Å⁻³

• Δρ_min = −1.46 e Å⁻³

Data collection: SMART (Bruker, 2000 ▶); cell refinement: SAINT (Bruker, 2000 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXL97.

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
O3—H3A⋯Br1i	0.83	2.58	3.340 (9)	154
O3—H3B⋯N1ii	1.10	2.41	3.466 (14)	162
O4—H4A⋯Br2iii	0.83	2.70	3.333 (9)	135
O4—H4A⋯O1iii	0.83	2.33	2.908 (14)	127
O4—H4B⋯Br1iv	1.02	2.31	3.210 (9)	147
C2—H2⋯O4v	0.94	2.59	3.319 (18)	134
C4—H4⋯Br2vi	0.94	2.80	3.534 (12)	135

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) ; (vi) .

supplementary crystallographic information

Comment

Coordination polymers are attracting great attention because of their potential applications such as in catalysis, magnetism, molecular recognition and other fields (Huang et al., 2004).

The asymmetric unit of the title compound, [MnBr₂(C₆H₄NO₂)(H₂O)₂]_n, contains one monomeric unit of the neutral linear coordination polymer (Fig. 1). Mn³⁺ ions are bridged by anionic pyridinecarboxylate (pic) ligands, thereby forming a one-dimensional zigzag chain-like structure along the c axis (Fig. 2). Mn³⁺ ions are six-coordinated in a distorted octahedral environment by two O atoms of the two different carboxylate groups, two O atoms of two water molecules and two Br atoms. Water molecules are trans with respect to each other, whereas Br atoms and O atoms of the carboxylate groups are cis with respect to each other, respectively. The complex displays intermolecular O—H···Br, O—H···N, O—H···O, C—H···O and C—H···Br hydrogen bonding (Table 1 and Fig. 2). There may also be intermolecular π-π interactions between adjacent pyridine rings, with a centroid-centroid distance of 3.993 (8) Å. The structure of the complex polymer is comparable with the structure of the anionic complex polymer, {[MnBr₂(pic)(H₂O)]^-}_n, in which the Mn²⁺ ions are linked to each other by pyridinecarboxylate bridges in a syn-anti mode (Kim et al., 2009).

Experimental

A solution of MnBr₂ × 4 H₂O (0.920 g, 3.208 mmol) and pyridine-2-carboxylic acid (0.200 g, 1.625 mmol) in H₂O (10 ml) was refluxed for 3 h. The solvent was removed in vacuum, the residue was dissolved in MeOH/H₂O (5 ml/5 ml) and filtered. After evaporation of the solvent, the residue was dried at 333 K, to give a pale pink powder (0.918 g). Crystals suitable for X-ray analysis were obtained by slow evaporation from a CH₃CN solution.

Refinement

H atoms were positioned geometrically and allowed to ride on their respective parent atoms [C—H = 0.94 Å and U_iso(H) = 1.2U_eq(C)]. The H atoms of the water molecules were located from Fourier difference maps, but not refined [U_iso(H) = 1.5U_eq(O)].

Figures

Fig. 1.

The repeat unit of the title compound, with displacement ellipsoids drawn at the 50% probability level for non-H atoms.

Fig. 2.

View of the unit-cell contents and chain-like structure of the title compound. Hydrogen-bond interactions are drawn with dashed lines.

Crystal data

[MnBr2(C6H4NO2)(H2O)2]	F(000) = 712
Mr = 372.89	Dx = 2.321 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2889 reflections
a = 10.290 (3) Å	θ = 2.6–28.2°
b = 13.814 (4) Å	µ = 8.71 mm−1
c = 7.978 (3) Å	T = 223 K
β = 109.810 (6)°	Plate, colorless
V = 1066.9 (6) Å3	0.25 × 0.23 × 0.10 mm
Z = 4

Data collection

Bruker SMART 1000 CCD diffractometer	2168 independent reflections
Radiation source: fine-focus sealed tube	1510 reflections with I > 2σ(I)
graphite	Rint = 0.060
φ and ω scans	θmax = 26.4°, θmin = 2.1°
Absorption correction: multi-scan (SADABS; Bruker, 2000)	h = −12→11
Tmin = 0.133, Tmax = 0.418	k = −17→17
6572 measured reflections	l = −5→9

Refinement

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.070	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.248	H-atom parameters constrained
S = 1.14	w = 1/[σ2(Fo2) + (0.135P)2 + 7.437P] where P = (Fo2 + 2Fc2)/3
2168 reflections	(Δ/σ)max < 0.001
127 parameters	Δρmax = 2.85 e Å−3
0 restraints	Δρmin = −1.46 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
Mn1	1.11555 (19)	0.12215 (13)	0.3085 (2)	0.0262 (5)
Br1	1.27174 (14)	0.06169 (8)	0.63672 (16)	0.0287 (4)
Br2	1.29649 (14)	0.06032 (9)	0.17035 (17)	0.0322 (4)
O1	0.9974 (9)	0.1781 (7)	0.0294 (12)	0.037 (2)
O2	0.9538 (9)	0.1716 (6)	0.4164 (12)	0.033 (2)
O3	1.0017 (9)	−0.0140 (6)	0.2414 (12)	0.039 (2)
H3A	0.9255	−0.0079	0.2534	0.059*
H3B	1.0868	−0.0659	0.2907	0.059*
O4	1.1968 (11)	0.2673 (6)	0.3608 (12)	0.039 (2)
H4A	1.1943	0.2857	0.4586	0.058*
H4B	1.1898	0.3074	0.2510	0.058*
N1	0.7263 (11)	0.3399 (7)	0.0142 (14)	0.031 (2)
C1	0.6010 (14)	0.3448 (9)	0.0408 (19)	0.035 (3)
H1	0.5611	0.4054	0.0464	0.042*
C2	0.5345 (14)	0.2620 (11)	0.059 (2)	0.041 (4)
H2	0.4469	0.2652	0.0714	0.049*
C3	0.5976 (14)	0.1726 (12)	0.0593 (18)	0.042 (4)
H3	0.5538	0.1153	0.0750	0.050*
C4	0.7258 (12)	0.1683 (9)	0.0361 (16)	0.027 (3)
H4	0.7690	0.1083	0.0367	0.032*
C5	0.7886 (12)	0.2528 (8)	0.0123 (14)	0.025 (3)
C6	0.9277 (13)	0.2547 (9)	−0.0176 (15)	0.027 (3)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Mn1	0.0264 (10)	0.0225 (9)	0.0289 (10)	−0.0013 (7)	0.0085 (8)	0.0024 (7)
Br1	0.0340 (8)	0.0267 (7)	0.0244 (7)	0.0015 (5)	0.0085 (5)	0.0002 (4)
Br2	0.0366 (8)	0.0356 (8)	0.0276 (7)	0.0081 (5)	0.0149 (6)	0.0039 (5)
O1	0.027 (5)	0.048 (5)	0.036 (5)	0.013 (4)	0.012 (4)	0.016 (4)
O2	0.029 (5)	0.039 (5)	0.038 (5)	0.003 (4)	0.024 (4)	−0.005 (4)
O3	0.042 (6)	0.026 (5)	0.049 (6)	−0.015 (4)	0.015 (5)	0.003 (4)
O4	0.058 (7)	0.033 (5)	0.030 (5)	−0.007 (4)	0.020 (5)	0.000 (4)
N1	0.032 (6)	0.031 (6)	0.028 (6)	0.006 (5)	0.007 (5)	0.003 (4)
C1	0.028 (7)	0.035 (7)	0.053 (8)	0.010 (5)	0.030 (6)	−0.007 (6)
C2	0.015 (6)	0.061 (10)	0.049 (9)	0.005 (6)	0.014 (6)	0.002 (7)
C3	0.024 (7)	0.063 (9)	0.037 (8)	−0.020 (7)	0.008 (6)	−0.002 (7)
C4	0.025 (6)	0.022 (6)	0.033 (7)	−0.004 (5)	0.009 (5)	0.001 (5)
C5	0.020 (6)	0.044 (7)	0.004 (5)	−0.003 (5)	−0.003 (4)	0.001 (4)
C6	0.025 (6)	0.040 (7)	0.008 (5)	−0.003 (5)	−0.005 (4)	0.007 (5)

Geometric parameters (Å, °)

Mn1—O4	2.158 (9)	N1—C5	1.365 (15)
Mn1—O3	2.184 (8)	N1—C1	1.378 (16)
Mn1—O2	2.224 (8)	C1—C2	1.366 (19)
Mn1—O1	2.281 (9)	C1—H1	0.94
Mn1—Br2	2.608 (2)	C2—C3	1.40 (2)
Mn1—Br1	2.699 (2)	C2—H2	0.94
O1—C6	1.261 (14)	C3—C4	1.394 (18)
O2—C6i	1.217 (14)	C3—H3	0.94
O3—H3A	0.83	C4—C5	1.378 (16)
O3—H3B	1.10	C4—H4	0.94
O4—H4A	0.83	C5—C6	1.529 (18)
O4—H4B	1.02	C6—O2ii	1.217 (14)
O4—Mn1—O3	171.1 (4)	Mn1—O4—H4B	115
O4—Mn1—O2	86.1 (4)	H4A—O4—H4B	129
O3—Mn1—O2	87.1 (3)	C5—N1—C1	120.9 (11)
O4—Mn1—O1	85.2 (4)	C2—C1—N1	120.3 (12)
O3—Mn1—O1	89.3 (3)	C2—C1—H1	119.9
O2—Mn1—O1	93.0 (3)	N1—C1—H1	119.9
O4—Mn1—Br2	95.8 (3)	C1—C2—C3	119.5 (12)
O3—Mn1—Br2	90.8 (3)	C1—C2—H2	120.3
O2—Mn1—Br2	177.4 (3)	C3—C2—H2	120.3
O1—Mn1—Br2	85.3 (2)	C4—C3—C2	119.9 (13)
O4—Mn1—Br1	92.1 (3)	C4—C3—H3	120.1
O3—Mn1—Br1	93.7 (2)	C2—C3—H3	120.1
O2—Mn1—Br1	89.9 (2)	C5—C4—C3	119.5 (12)
O1—Mn1—Br1	175.9 (2)	C5—C4—H4	120.3
Br2—Mn1—Br1	91.89 (7)	C3—C4—H4	120.3
C6—O1—Mn1	129.5 (8)	N1—C5—C4	120.0 (12)
C6i—O2—Mn1	136.7 (9)	N1—C5—C6	117.1 (10)
Mn1—O3—H3A	110	C4—C5—C6	122.9 (11)
Mn1—O3—H3B	100	O2ii—C6—O1	130.0 (13)
H3A—O3—H3B	134	O2ii—C6—C5	115.9 (11)
Mn1—O4—H4A	109	O1—C6—C5	114.1 (10)
O4—Mn1—O1—C6	−47.0 (11)	C2—C3—C4—C5	−0.3 (19)
O3—Mn1—O1—C6	125.9 (11)	C1—N1—C5—C4	0.4 (17)
O2—Mn1—O1—C6	38.8 (11)	C1—N1—C5—C6	−179.8 (10)
Br2—Mn1—O1—C6	−143.2 (11)	C3—C4—C5—N1	1.0 (18)
O4—Mn1—O2—C6i	−3.1 (12)	C3—C4—C5—C6	−178.8 (10)
O3—Mn1—O2—C6i	−177.3 (12)	Mn1—O1—C6—O2ii	107.2 (14)
O1—Mn1—O2—C6i	−88.1 (12)	Mn1—O1—C6—C5	−73.5 (12)
Br1—Mn1—O2—C6i	89.0 (12)	N1—C5—C6—O2ii	−19.0 (15)
C5—N1—C1—C2	−2(2)	C4—C5—C6—O2ii	160.8 (12)
N1—C1—C2—C3	3(2)	N1—C5—C6—O1	161.6 (10)
C1—C2—C3—C4	−2(2)	C4—C5—C6—O1	−18.6 (15)

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

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3A···Br1iii	0.83	2.58	3.340 (9)	154
O3—H3B···N1iv	1.10	2.41	3.466 (14)	162
O4—H4A···Br2i	0.83	2.70	3.333 (9)	135
O4—H4A···O1i	0.83	2.33	2.908 (14)	127
O4—H4B···Br1ii	1.02	2.31	3.210 (9)	147
C2—H2···O4v	0.94	2.59	3.319 (18)	134
C4—H4···Br2vi	0.94	2.80	3.534 (12)	135

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