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Acta Cryst. (2008). E64, m307    [ doi:10.1107/S1600536808000226 ]

Bis{[mu]-2,2'-[1,1'-(ethane-1,2-diyldinitrilo)diethylidyne]diphenolato-[kappa]5O,N,N',O':O}bis[chloridomanganese(III)\]

V. S. Thampidas, T. Radhakrishnan and R. D. Pike

Abstract top

The title compound, [Mn2(C18H18N2O2)2Cl2], was synthesized by the reaction between manganese(II) o-chlorobenzoate and the Schiff base generated in situ by the condensation of ethane-1,2-diamine and o-hydroxyacetophenone. The centrosymmetric dimer contains two Jahn-Teller-distorted manganese(III) ions, each in an octahedral geometry, connected through two phenoxy bridges from two ligands.

Comment top

Manganese coordination chemistry, in recent decades, has been in intense research focus in connection with developments in diverse fields as bioinorganic modeling (Triller et al., 2002), asymmetric catalysis (Larrow & Jacobsen, 2004), molecular magnetism (Christou, 2005) etc. Schiff base ligands with nitrogen and oxygen donor atoms seem to stabilize the various oxidation states of manganese better than any other ligand systems, as it is evident from the sheer number of publications in this area (Vites & Lynam, 1998). The penta-coordinate [Mn(salen)Cl] (H2salen = N,N'-bis(salicylidene)-1,2-diaminoethane) was one of the earliest crystallographically characterized manganese(III) Schiff base complexes (Pecoraro & Butler, 1986). This may be considered as a prototype molecule, that has led to the development of large number of manganese(III) complexes with a square planar MnN2O2 core, stabilized by a chiral-salen ligand and a chloride ion in the axial position (Zhang et al., 1990; Jacobsen et al., 1991). In our effort to synthesize dimeric manganese(III) complexes of a salen-like ligand, N,N'-bis(o-hydroxyacetophenonylidene)-1,2-diaminoethane with o-chlorobenzoate as an ancillary ligand, we unexpectedly obtained a dimeric manganese(III) complex stabilized by the Schiff base and two axial chloride ligands. Here we report the crystal structure of the new dichloride dimer (Fig. 1).

In the title compound, the centrosymmetric dimer is crystallographically half independent and consists of two MnIII atoms, linked by two phenolic O atoms of two ligands. Two Mn—N bonds and two Mn—O bonds complete the equatorial square plane geometry around the MnIII atom (Table 1). This leaves the two axial positions open for coordination to the Cl atoms, leading to the formation of a rare dichloride dimer. Jahn-Teller distortion elongates the Mn—Cl bond [Mn1—Cl1 = 2.4633 (6) Å] substantially, which is comparable to the Mn—Cl bond length of 2.461 (1)Å in the square pyramidal [Mn(salen)Cl] (Pecoraro & Butler, 1986). But the elongation is not as much as seen in the square pyramidal [Mn(5—Cl-salen)Cl] (Horwitz et al., 1995) and octahedral [Mn(salen)Cl(H2O)] (Panja et al., 2003), where Mn—Cl distances are 2.572 (1) Å and 2.621 (6) Å, respectively. Jahn-Teller effect is also apparent in the longer Mn—O bond [Mn1—O1 = 2.4720 (16) Å] of the Mn2(µ-O)2 diamond core of the dimer. This makes the Mn—O—Mn bridge of the complex considerably weaker than that in the diazide dimer [Mn2(L)2(N3)2] (H2L = N,N'-bis(o-hydroxyacetophenonylidene)-1,2-diaminoethane) (Saha et al., 2004), where the corresponding bond length is 2.375 (5) Å. The Mn···Mn separation in the title compound is 3.453 (2) Å, compared to 3.341 (2)Å in [Mn2(L)2(N3)2].

Related literature top

For related literature, see: Christou (2005); Horwitz et al. (1995); Jacobsen et al. (1991); Larrow & Jacobsen (2004); Panja et al. (2003); Pecoraro & Butler (1986); Saha et al. (2004); Triller et al. (2002); Vites & Lynam (1998); Zhang et al. (1990).

Experimental top

To a solution of Mn(o—Cl—C6H4CO2)2.2H2O (1.00 g, 2.49 mmol) and o-hydroxyacetophenone (0.68 g, 4.98 mmol) in methanol (40 ml), ethane-1,2-diamine (0.14 g, 2.49 mmol) was added. The solution was stirred for 20 min, filtered and left to evaporation in an open conical flask. Brown crystals were deposited in 2–3 days. These were collected by filtration, washed with methanol, and dried in air (yield 0.80 g, 80.6% based on Mn).

Refinement top

H atoms were positioned geometrically and refined as riding atoms, with C—H = 0.95 (CH) and 0.99Å (CH2) and Uiso(H) = 1.2Ueq(C), and with C—H = 0.98Å (CH3) and Uiso(H) = 1.5Ueq(C).

Computing details top

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PRPKAPPA (Ferguson, 1999).

Figures top
[Figure 1] Fig. 1. Molecular structure of the title compound. Displacement ellipsoids are drawn at the 50% probability level. [Symmetry code: (i) -x, 2 - y, -z.]
Bis{µ-2,2'-[1,1'-(ethane-1,2-diyldinitrilo)diethylidyne]diphenolato- κ5O,N,N',O':O}bis[chloridomanganese(III)] top
Crystal data top
[Mn2(C18H18N2O2)2Cl2]Z = 1
Mr = 769.47F000 = 396
Triclinic, P1Dx = 1.584 Mg m−3
Hall symbol: -P 1Cu Kα radiation
λ = 1.54178 Å
a = 7.8261 (3) ÅCell parameters from 2781 reflections
b = 9.8046 (3) Åθ = 9.8–71.6º
c = 11.2372 (4) ŵ = 8.29 mm−1
α = 97.207 (2)ºT = 100 (2) K
β = 94.701 (2)ºPrism, brown
γ = 108.081 (2)º0.28 × 0.14 × 0.14 mm
V = 806.49 (5) Å3
Data collection top
Bruker SMART APEXII CCD
diffractometer		2781 independent reflections
Radiation source: fine-focus sealed tube2733 reflections with I > 2σ(I)
Monochromator: graphiteRint = 0.033
T = 100(2) Kθmax = 67.0º
φ and ω scansθmin = 4.0º
Absorption correction: multi-scan
(SAINT-Plus; Bruker, 2004)		h = −9→9
Tmin = 0.205, Tmax = 0.390k = −11→11
12822 measured reflectionsl = −13→12
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.032H-atom parameters constrained
wR(F2) = 0.088  w = 1/[σ2(Fo2) + (0.0396P)2 + 1.0982P]
where P = (Fo2 + 2Fc2)/3
S = 1.10(Δ/σ)max = 0.001
2781 reflectionsΔρmax = 0.39 e Å−3
219 parametersΔρmin = −0.44 e Å−3
Primary atom site location: structure-invariant direct methodsExtinction correction: none
Crystal data top
[Mn2(C18H18N2O2)2Cl2]γ = 108.081 (2)º
Mr = 769.47V = 806.49 (5) Å3
Triclinic, P1Z = 1
a = 7.8261 (3) ÅCu Kα
b = 9.8046 (3) ŵ = 8.29 mm−1
c = 11.2372 (4) ÅT = 100 (2) K
α = 97.207 (2)º0.28 × 0.14 × 0.14 mm
β = 94.701 (2)º
Data collection top
Bruker SMART APEXII CCD
diffractometer		2781 independent reflections
Absorption correction: multi-scan
(SAINT-Plus; Bruker, 2004)		2733 reflections with I > 2σ(I)
Tmin = 0.205, Tmax = 0.390Rint = 0.033
12822 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.032219 parameters
wR(F2) = 0.088H-atom parameters constrained
S = 1.10Δρmax = 0.39 e Å−3
2781 reflectionsΔρmin = −0.44 e Å−3
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Mn10.03321 (5)0.93493 (4)0.13283 (3)0.00849 (13)
Cl10.23277 (7)0.82169 (6)0.23406 (5)0.01447 (15)
O10.1568 (2)0.96398 (17)−0.00716 (14)0.0108 (3)
O20.1517 (2)1.12309 (17)0.21677 (14)0.0118 (3)
N1−0.1287 (3)0.7452 (2)0.04014 (18)0.0107 (4)
N2−0.1560 (3)0.9047 (2)0.24675 (17)0.0109 (4)
C180.1226 (3)1.1893 (3)0.3192 (2)0.0114 (5)
C12−0.1614 (3)0.9876 (3)0.3457 (2)0.0107 (5)
C50.1437 (3)0.6051 (3)−0.1622 (2)0.0137 (5)
H50.06870.5063−0.17700.016*
C7−0.0921 (3)0.6659 (2)−0.0498 (2)0.0112 (5)
C8−0.2364 (3)0.5291 (3)−0.1141 (2)0.0142 (5)
H8A−0.25280.4528−0.06340.021*
H8B−0.19930.4970−0.19100.021*
H8C−0.35090.5488−0.12970.021*
C20.3629 (3)0.8946 (3)−0.1229 (2)0.0119 (5)
H20.43790.9934−0.11090.014*
C10.2018 (3)0.8569 (2)−0.0705 (2)0.0102 (4)
C11−0.3108 (3)0.9334 (3)0.4225 (2)0.0160 (5)
H11A−0.42500.93750.38300.024*
H11B−0.28020.99460.50220.024*
H11C−0.32380.83280.43210.024*
C9−0.3112 (3)0.7098 (3)0.0770 (2)0.0135 (5)
H9A−0.37380.60360.05770.016*
H9B−0.38290.75880.03230.016*
C13−0.0262 (3)1.1327 (3)0.3837 (2)0.0123 (5)
C14−0.0442 (3)1.2227 (3)0.4882 (2)0.0158 (5)
H14−0.14391.18740.53150.019*
C60.0872 (3)0.7094 (3)−0.0912 (2)0.0106 (4)
C170.2500 (3)1.3270 (3)0.3664 (2)0.0141 (5)
H170.35421.36220.32700.017*
C10−0.2963 (3)0.7598 (3)0.2119 (2)0.0139 (5)
H10A−0.41460.76520.23310.017*
H10B−0.26370.68890.25690.017*
C30.4149 (3)0.7907 (3)−0.1920 (2)0.0138 (5)
H30.52470.8183−0.22690.017*
C160.2281 (3)1.4120 (3)0.4680 (2)0.0165 (5)
H160.31421.50540.49630.020*
C40.3054 (3)0.6445 (3)−0.2101 (2)0.0146 (5)
H40.34260.5726−0.25550.018*
C150.0780 (4)1.3594 (3)0.5286 (2)0.0184 (5)
H150.06041.41770.59760.022*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Mn10.0089 (2)0.0085 (2)0.0068 (2)0.00102 (14)0.00293 (13)0.00013 (14)
Cl10.0154 (3)0.0175 (3)0.0120 (3)0.0072 (2)0.0016 (2)0.0030 (2)
O10.0127 (8)0.0106 (8)0.0091 (8)0.0036 (6)0.0037 (6)0.0006 (6)
O20.0130 (8)0.0121 (8)0.0087 (8)0.0018 (6)0.0039 (6)0.0004 (6)
N10.0095 (9)0.0113 (9)0.0110 (10)0.0017 (7)0.0032 (7)0.0036 (8)
N20.0104 (9)0.0115 (9)0.0110 (10)0.0028 (8)0.0027 (7)0.0031 (8)
C180.0136 (11)0.0143 (11)0.0085 (11)0.0074 (9)0.0005 (9)0.0026 (9)
C120.0108 (11)0.0160 (11)0.0078 (11)0.0072 (9)0.0015 (8)0.0042 (9)
C50.0182 (12)0.0103 (11)0.0109 (11)0.0027 (9)0.0004 (9)0.0008 (9)
C70.0159 (12)0.0108 (11)0.0068 (11)0.0040 (9)−0.0004 (9)0.0029 (9)
C80.0142 (12)0.0132 (11)0.0129 (12)0.0017 (9)0.0029 (9)0.0004 (9)
C20.0119 (11)0.0135 (11)0.0089 (11)0.0027 (9)−0.0011 (9)0.0021 (9)
C10.0121 (11)0.0128 (11)0.0061 (10)0.0052 (9)−0.0004 (8)0.0011 (9)
C110.0154 (12)0.0188 (12)0.0129 (12)0.0037 (10)0.0059 (9)0.0014 (10)
C90.0094 (11)0.0138 (11)0.0154 (12)0.0012 (9)0.0037 (9)0.0011 (9)
C130.0139 (12)0.0150 (11)0.0087 (11)0.0056 (9)0.0014 (9)0.0015 (9)
C140.0166 (12)0.0207 (12)0.0108 (12)0.0064 (10)0.0044 (9)0.0023 (10)
C60.0117 (11)0.0136 (11)0.0062 (10)0.0041 (9)−0.0009 (8)0.0015 (9)
C170.0143 (12)0.0150 (11)0.0121 (11)0.0029 (9)0.0028 (9)0.0029 (9)
C100.0119 (11)0.0134 (11)0.0148 (12)0.0005 (9)0.0057 (9)0.0039 (9)
C30.0117 (11)0.0199 (12)0.0096 (11)0.0049 (9)0.0027 (9)0.0009 (9)
C160.0194 (13)0.0137 (11)0.0135 (12)0.0028 (10)0.0005 (9)−0.0010 (10)
C40.0169 (12)0.0154 (12)0.0123 (12)0.0078 (10)0.0021 (9)−0.0021 (9)
C150.0242 (13)0.0196 (13)0.0117 (12)0.0089 (11)0.0035 (10)−0.0021 (10)
Geometric parameters (Å, °) top
Mn1—O21.8738 (16)C8—H8C0.9800
Mn1—O11.9191 (16)C2—C31.385 (3)
Mn1—N11.9964 (19)C2—C11.400 (3)
Mn1—N22.0129 (19)C2—H20.9500
Mn1—Cl12.4633 (6)C1—C61.423 (3)
Mn1—O1i2.4720 (16)C11—H11A0.9800
O1—C11.348 (3)C11—H11B0.9800
O1—Mn1i2.4720 (16)C11—H11C0.9800
O2—C181.321 (3)C9—C101.517 (3)
N1—C71.302 (3)C9—H9A0.9900
N1—C91.469 (3)C9—H9B0.9900
N2—C121.305 (3)C13—C141.422 (3)
N2—C101.483 (3)C14—C151.378 (4)
C18—C171.413 (3)C14—H140.9500
C18—C131.424 (3)C17—C161.382 (3)
C12—C131.471 (3)C17—H170.9500
C12—C111.513 (3)C10—H10A0.9900
C5—C41.379 (4)C10—H10B0.9900
C5—C61.418 (3)C3—C41.402 (3)
C5—H50.9500C3—H30.9500
C7—C61.467 (3)C16—C151.398 (4)
C7—C81.510 (3)C16—H160.9500
C8—H8A0.9800C4—H40.9500
C8—H8B0.9800C15—H150.9500
O2—Mn1—O195.14 (7)O1—C1—C2118.2 (2)
O2—Mn1—N1170.58 (8)O1—C1—C6122.4 (2)
O1—Mn1—N187.86 (7)C2—C1—C6119.3 (2)
O2—Mn1—N290.36 (7)C12—C11—H11A109.5
O1—Mn1—N2163.69 (8)C12—C11—H11B109.5
N1—Mn1—N284.44 (8)H11A—C11—H11B109.5
O2—Mn1—Cl195.48 (5)C12—C11—H11C109.5
O1—Mn1—Cl196.66 (5)H11A—C11—H11C109.5
N1—Mn1—Cl193.03 (6)H11B—C11—H11C109.5
N2—Mn1—Cl198.09 (6)N1—C9—C10109.25 (19)
O2—Mn1—O1i88.58 (6)N1—C9—H9A109.8
O1—Mn1—O1i77.02 (7)C10—C9—H9A109.8
N1—Mn1—O1i83.39 (7)N1—C9—H9B109.8
N2—Mn1—O1i87.80 (7)C10—C9—H9B109.8
Cl1—Mn1—O1i172.81 (4)H9A—C9—H9B108.3
C1—O1—Mn1121.87 (14)C14—C13—C18117.7 (2)
C1—O1—Mn1i112.89 (13)C14—C13—C12119.4 (2)
Mn1—O1—Mn1i102.98 (7)C18—C13—C12122.9 (2)
C18—O2—Mn1130.34 (15)C15—C14—C13122.2 (2)
C7—N1—C9121.6 (2)C15—C14—H14118.9
C7—N1—Mn1127.36 (16)C13—C14—H14118.9
C9—N1—Mn1110.67 (14)C5—C6—C1118.3 (2)
C12—N2—C10119.38 (19)C5—C6—C7119.8 (2)
C12—N2—Mn1129.33 (16)C1—C6—C7121.7 (2)
C10—N2—Mn1111.08 (14)C16—C17—C18122.1 (2)
O2—C18—C17116.5 (2)C16—C17—H17118.9
O2—C18—C13125.0 (2)C18—C17—H17118.9
C17—C18—C13118.5 (2)N2—C10—C9109.88 (18)
N2—C12—C13121.5 (2)N2—C10—H10A109.7
N2—C12—C11119.1 (2)C9—C10—H10A109.7
C13—C12—C11119.4 (2)N2—C10—H10B109.7
C4—C5—C6121.3 (2)C9—C10—H10B109.7
C4—C5—H5119.4H10A—C10—H10B108.2
C6—C5—H5119.4C2—C3—C4119.9 (2)
N1—C7—C6120.7 (2)C2—C3—H3120.1
N1—C7—C8119.9 (2)C4—C3—H3120.1
C6—C7—C8119.4 (2)C17—C16—C15119.4 (2)
C7—C8—H8A109.5C17—C16—H16120.3
C7—C8—H8B109.5C15—C16—H16120.3
H8A—C8—H8B109.5C5—C4—C3119.9 (2)
C7—C8—H8C109.5C5—C4—H4120.0
H8A—C8—H8C109.5C3—C4—H4120.0
H8B—C8—H8C109.5C14—C15—C16119.8 (2)
C3—C2—C1121.3 (2)C14—C15—H15120.1
C3—C2—H2119.4C16—C15—H15120.1
C1—C2—H2119.4
O2—Mn1—O1—C1144.83 (16)Mn1—N1—C7—C8−176.24 (16)
N1—Mn1—O1—C1−44.12 (17)Mn1—O1—C1—C2−145.77 (17)
N2—Mn1—O1—C1−105.9 (3)Mn1i—O1—C1—C290.9 (2)
Cl1—Mn1—O1—C148.69 (16)Mn1—O1—C1—C637.8 (3)
O1i—Mn1—O1—C1−127.83 (18)Mn1i—O1—C1—C6−85.5 (2)
O2—Mn1—O1—Mn1i−87.35 (7)C3—C2—C1—O1−178.2 (2)
N1—Mn1—O1—Mn1i83.71 (7)C3—C2—C1—C6−1.7 (3)
N2—Mn1—O1—Mn1i21.9 (3)C7—N1—C9—C10149.6 (2)
Cl1—Mn1—O1—Mn1i176.51 (4)Mn1—N1—C9—C10−36.7 (2)
O1i—Mn1—O1—Mn1i0.0O2—C18—C13—C14−175.6 (2)
O1—Mn1—O2—C18172.36 (19)C17—C18—C13—C144.1 (3)
N2—Mn1—O2—C187.7 (2)O2—C18—C13—C123.3 (4)
Cl1—Mn1—O2—C18−90.43 (19)C17—C18—C13—C12−177.0 (2)
O1i—Mn1—O2—C1895.52 (19)N2—C12—C13—C14176.1 (2)
O1—Mn1—N1—C725.1 (2)C11—C12—C13—C14−3.6 (3)
N2—Mn1—N1—C7−169.3 (2)N2—C12—C13—C18−2.9 (3)
Cl1—Mn1—N1—C7−71.4 (2)C11—C12—C13—C18177.4 (2)
O1i—Mn1—N1—C7102.3 (2)C18—C13—C14—C15−1.2 (4)
O1—Mn1—N1—C9−148.16 (15)C12—C13—C14—C15179.8 (2)
N2—Mn1—N1—C917.44 (15)C4—C5—C6—C10.1 (3)
Cl1—Mn1—N1—C9115.28 (14)C4—C5—C6—C7175.1 (2)
O1i—Mn1—N1—C9−70.98 (15)O1—C1—C6—C5178.0 (2)
O2—Mn1—N2—C12−7.3 (2)C2—C1—C6—C51.6 (3)
O1—Mn1—N2—C12−117.2 (3)O1—C1—C6—C73.1 (3)
N1—Mn1—N2—C12−179.4 (2)C2—C1—C6—C7−173.3 (2)
Cl1—Mn1—N2—C1288.3 (2)N1—C7—C6—C5161.2 (2)
O1i—Mn1—N2—C12−95.9 (2)C8—C7—C6—C5−20.0 (3)
O2—Mn1—N2—C10178.04 (15)N1—C7—C6—C1−24.0 (3)
O1—Mn1—N2—C1068.1 (3)C8—C7—C6—C1154.8 (2)
N1—Mn1—N2—C105.90 (15)O2—C18—C17—C16175.2 (2)
Cl1—Mn1—N2—C10−86.38 (15)C13—C18—C17—C16−4.5 (4)
O1i—Mn1—N2—C1089.48 (15)C12—N2—C10—C9157.5 (2)
Mn1—O2—C18—C17172.84 (15)Mn1—N2—C10—C9−27.3 (2)
Mn1—O2—C18—C13−7.4 (3)N1—C9—C10—N241.7 (3)
C10—N2—C12—C13−179.6 (2)C1—C2—C3—C4−0.1 (4)
Mn1—N2—C12—C136.2 (3)C18—C17—C16—C151.8 (4)
C10—N2—C12—C110.2 (3)C6—C5—C4—C3−1.9 (4)
Mn1—N2—C12—C11−174.11 (16)C2—C3—C4—C51.9 (4)
C9—N1—C7—C6175.2 (2)C13—C14—C15—C16−1.5 (4)
Mn1—N1—C7—C62.5 (3)C17—C16—C15—C141.2 (4)
C9—N1—C7—C8−3.6 (3)
Symmetry codes: (i) −x, −y+2, −z.
Table 1
Selected geometric parameters (Å, °) top
Mn1—O21.8738 (16)Mn1—N22.0129 (19)
Mn1—O11.9191 (16)Mn1—Cl12.4633 (6)
Mn1—N11.9964 (19)Mn1—O1i2.4720 (16)
O2—Mn1—O195.14 (7)N1—Mn1—Cl193.03 (6)
O2—Mn1—N1170.58 (8)N2—Mn1—Cl198.09 (6)
O1—Mn1—N187.86 (7)O2—Mn1—O1i88.58 (6)
O2—Mn1—N290.36 (7)O1—Mn1—O1i77.02 (7)
O1—Mn1—N2163.69 (8)N1—Mn1—O1i83.39 (7)
N1—Mn1—N284.44 (8)N2—Mn1—O1i87.80 (7)
O2—Mn1—Cl195.48 (5)Cl1—Mn1—O1i172.81 (4)
O1—Mn1—Cl196.66 (5)Mn1—O1—Mn1i102.98 (7)
Symmetry codes: (i) −x, −y+2, −z.
Acknowledgements top

The authors acknowledge the authorities of SN College, Varkala, Kerala, India for access to the college facilities for this research. The authors also acknowledge the NSF (grant No. CHE-0443345) and the College of William and Mary for the purchase of the X-ray equipment.

references
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