Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807032801/bt2430sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807032801/bt2430Isup2.hkl |
CCDC reference: 657552
Key indicators
- Single-crystal X-ray study
- T = 120 K
- Mean (C-C) = 0.004 Å
- R factor = 0.037
- wR factor = 0.098
- Data-to-parameter ratio = 21.3
checkCIF/PLATON results
No syntax errors found
Alert level C PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X) Br1 - Mn1 .. 5.79 su
Alert level G PLAT794_ALERT_5_G Check Predicted Bond Valency for Mn1 (3) 2.73
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 1 ALERT level C = Check and explain 1 ALERT level G = General alerts; check 0 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 0 ALERT type 3 Indicator that the structure quality may be low 0 ALERT type 4 Improvement, methodology, query or suggestion 1 ALERT type 5 Informative message, check
For related literature, see: Allen (2002); Ferreira et al. (2004); Glerup et al. (1994); Goodson & Hodgson (1989); Goodson et al. (1990); Harmjanz (1997); Heuwing (2004); Kitajima et al. (1991); Mukhopadhyay et al. (2004); Pohl et al. (2000); Schneider (2000); Waden (1999); Wu et al. (2004).
The synthesis of the btmgp-ligand is described in the literature (Pohl et al., 2000). (II): the reaction of MnBr2 (215 mg, 1 mmol) in 10 ml ABS. MeCN with btmgp (297 mg, 1.1 mmol) leads to a suspension with a white precipitate. After 30 min at reflux the blear solution had been filtered. By cooling down slowly, colourless crystals of (II) were be obtained. (I): slow diffusion of air to the mother liquor of (II) leads after several weeks to few dark red crystals of (I) suitable for X-ray diffraction.
Hydrogen atoms located from difference Fourier maps were refined at idealized positions riding on the carbon atoms with isotropic displacement parameters Uiso(H) = 1.2U(Ceq) or 1.5U(CH3). All CH3 hydrogen atoms were allowed to rotate but not to tip.
Since evidence was found that an oxo-bridged manganese cluster participates significantly in the water oxidation process of photosystem II the research and synthesis of oxo-complexes, which contain manganese atoms in high oxidation states of +III or +IV, have become of considerable interest in bioinorganic chemistry (Mukhopadhyay et al., 2004). Recently, a heterocuban oxo-bridged manganese cluster was probably identify as the oxgen-evolving center (OEC) which catalyzes one of the most thermodynamically demanding reactions in biology: the photoinduced oxidation of water (Ferreira et al., 2004). As well the occurrence of manganese hydroxo- and oxo-complexes in the active centres of superoxiddismutases or katalases and the attempt to understand the catalytic processes in these metalloproteins create a need for small biological relevant modell complexes (Wu et al., 2004). In search of bifunctional ligands able to stabilize unusually high metal oxidation states, we have extended our studies to guanidyl-type systems with N-donor functions. The first derivative, the ligand bis(tetramethylguanidino)propylene (btmgp) and its complexes with copper, iron, nickel, lithium, palladium and cobalt have recently been investigated (Harmjanz, 1997; Waden, 1999; Pohl et al., 2000; Schneider, 2000; Heuwing, 2004).
We have now examined the reaction behaviour of the complex [MnBr2(btmgp)] (II) containing the ligand bis(tetra-methylguanidino)propylene (btmgp), towards molecular oxygen which leads to the title complex (I) with distorted square pyramidal coordination of the manganese atoms (Figure 1). There are many examples of bis(µ-oxo)-dimanganese complexes of Mn(III,IV) and Mn(IV,IV) species. However, dimanganese(III,III) species are rare, only a few examples are noted in literature and no compound with a MnIII2O2 core, a bidentate imin-donor ligand and two terminal co-ligands is found in the CSD (Allen, 2002) to date.
There are only few examples of the dimanganese(III,III) species with tetradentate N-donor ligands and octahedrally coordinated manganese centres. The geometric centre of (I) lies on a crystallographic inversion centre and the resulting Mn2O2 core is thus strictly planar. The distance of the Mn atom to the N2O2 plane is 0.207 (1) Å and the nonbonding Mn–Mn distance is 2.7068 (9) Å. The Mn–O and Mn–N bond lengths (Table 1) are comparable with those from other characterized MnIII2O2 complexes that range from 1.787 (6) to 1.863 (8) and 2.084 (6) to 2.468 (10) Å, respectively (Goodson & Hodgson, 1989; Goodson et al., 1990; Kitajima et al., 1991; Glerup et al., 1994). Cell packing (Figure 2) exhibits C–H···Br intermolecular hydrogen bonds (see table) that link molecules to endless chains along [010].
For related literature, see: Allen (2002); Ferreira et al. (2004); Glerup et al. (1994); Goodson & Hodgson (1989); Goodson et al. (1990); Harmjanz (1997); Heuwing (2004); Kitajima et al. (1991); Mukhopadhyay et al. (2004); Pohl et al. (2000); Schneider (2000); Waden (1999); Wu et al. (2004).
Data collection: SMART (Bruker, 2002); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Bruker, 2002); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
[Mn2Br2O2(C13H30N6)2] | F(000) = 1744 |
Mr = 842.56 | Dx = 1.569 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2yc | Cell parameters from 4977 reflections |
a = 19.592 (4) Å | θ = 2.3–28.1° |
b = 9.2077 (17) Å | µ = 2.99 mm−1 |
c = 19.767 (4) Å | T = 120 K |
β = 90.03 (1)° | Block, red |
V = 3566.0 (11) Å3 | 0.43 × 0.40 × 0.38 mm |
Z = 4 |
Bruker SMART CCD area-detector diffractometer | 4242 independent reflections |
Radiation source: sealed tube | 3584 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.038 |
φ and ω scans | θmax = 27.9°, θmin = 2.1° |
Absorption correction: multi-scan (SADABS; Bruker, 2002) | h = −25→24 |
Tmin = 0.290, Tmax = 0.322 | k = −12→12 |
16870 measured reflections | l = −26→25 |
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)] = 0.037 | Hydrogen site location: difference Fourier map |
wR(F2) = 0.098 | H-atom parameters constrained |
S = 1.04 | w = 1/[σ2(Fo2) + (0.0555P)2 + 4.3912P] where P = (Fo2 + 2Fc2)/3 |
4242 reflections | (Δ/σ)max = 0.001 |
199 parameters | Δρmax = 0.85 e Å−3 |
0 restraints | Δρmin = −0.43 e Å−3 |
[Mn2Br2O2(C13H30N6)2] | V = 3566.0 (11) Å3 |
Mr = 842.56 | Z = 4 |
Monoclinic, C2/c | Mo Kα radiation |
a = 19.592 (4) Å | µ = 2.99 mm−1 |
b = 9.2077 (17) Å | T = 120 K |
c = 19.767 (4) Å | 0.43 × 0.40 × 0.38 mm |
β = 90.03 (1)° |
Bruker SMART CCD area-detector diffractometer | 4242 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2002) | 3584 reflections with I > 2σ(I) |
Tmin = 0.290, Tmax = 0.322 | Rint = 0.038 |
16870 measured reflections |
R[F2 > 2σ(F2)] = 0.037 | 0 restraints |
wR(F2) = 0.098 | H-atom parameters constrained |
S = 1.04 | Δρmax = 0.85 e Å−3 |
4242 reflections | Δρmin = −0.43 e Å−3 |
199 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
Br1 | 0.144709 (14) | 0.50925 (3) | 0.428308 (14) | 0.02284 (10) | |
Mn1 | 0.181051 (19) | 0.74639 (4) | 0.503835 (19) | 0.01510 (11) | |
O1 | 0.24607 (9) | 0.82399 (19) | 0.44903 (9) | 0.0175 (4) | |
N1 | 0.11406 (11) | 0.6931 (2) | 0.58156 (11) | 0.0176 (4) | |
N2 | 0.17932 (12) | 0.7459 (2) | 0.67596 (11) | 0.0202 (5) | |
N3 | 0.11891 (13) | 0.5314 (2) | 0.67283 (12) | 0.0225 (5) | |
N4 | 0.10314 (11) | 0.8676 (2) | 0.45995 (11) | 0.0179 (4) | |
N5 | 0.15979 (11) | 1.0805 (2) | 0.43426 (11) | 0.0198 (5) | |
N6 | 0.08802 (13) | 0.9809 (2) | 0.35454 (12) | 0.0227 (5) | |
C1 | 0.13683 (13) | 0.6562 (3) | 0.64095 (13) | 0.0186 (5) | |
C2 | 0.18411 (16) | 0.8976 (3) | 0.65726 (14) | 0.0257 (6) | |
H2A | 0.1415 | 0.9282 | 0.6356 | 0.038* | |
H2B | 0.2221 | 0.9110 | 0.6257 | 0.038* | |
H2C | 0.1920 | 0.9563 | 0.6979 | 0.038* | |
C3 | 0.24051 (15) | 0.6906 (3) | 0.70875 (15) | 0.0287 (6) | |
H3A | 0.2340 | 0.5880 | 0.7202 | 0.043* | |
H3B | 0.2493 | 0.7461 | 0.7502 | 0.043* | |
H3C | 0.2795 | 0.7005 | 0.6780 | 0.043* | |
C4 | 0.11317 (19) | 0.5181 (3) | 0.74572 (15) | 0.0316 (7) | |
H4A | 0.1244 | 0.6113 | 0.7669 | 0.047* | |
H4B | 0.1449 | 0.4434 | 0.7619 | 0.047* | |
H4C | 0.0664 | 0.4906 | 0.7576 | 0.047* | |
C5 | 0.10379 (16) | 0.4014 (3) | 0.63481 (15) | 0.0277 (6) | |
H5A | 0.1090 | 0.4211 | 0.5864 | 0.042* | |
H5B | 0.0568 | 0.3709 | 0.6440 | 0.042* | |
H5C | 0.1353 | 0.3239 | 0.6482 | 0.042* | |
C6 | 0.04418 (13) | 0.6489 (3) | 0.56308 (14) | 0.0204 (5) | |
H6A | 0.0186 | 0.6224 | 0.6044 | 0.025* | |
H6B | 0.0460 | 0.5624 | 0.5334 | 0.025* | |
C7 | 0.00763 (13) | 0.7711 (3) | 0.52682 (14) | 0.0218 (5) | |
H7A | −0.0414 | 0.7461 | 0.5232 | 0.026* | |
H7B | 0.0113 | 0.8603 | 0.5546 | 0.026* | |
C8 | 0.03464 (13) | 0.8032 (3) | 0.45688 (14) | 0.0202 (5) | |
H8A | 0.0364 | 0.7122 | 0.4303 | 0.024* | |
H8B | 0.0033 | 0.8711 | 0.4336 | 0.024* | |
C9 | 0.11696 (13) | 0.9723 (3) | 0.41713 (14) | 0.0180 (5) | |
C10 | 0.17422 (15) | 1.1128 (3) | 0.50419 (14) | 0.0236 (6) | |
H10A | 0.1381 | 1.0723 | 0.5328 | 0.035* | |
H10B | 0.1763 | 1.2182 | 0.5105 | 0.035* | |
H10C | 0.2181 | 1.0696 | 0.5169 | 0.035* | |
C11 | 0.21030 (15) | 1.1363 (3) | 0.38758 (15) | 0.0261 (6) | |
H11A | 0.1973 | 1.1105 | 0.3412 | 0.039* | |
H11B | 0.2549 | 1.0938 | 0.3981 | 0.039* | |
H11C | 0.2128 | 1.2422 | 0.3918 | 0.039* | |
C12 | 0.07306 (16) | 0.8521 (3) | 0.31598 (15) | 0.0286 (6) | |
H12A | 0.0875 | 0.7662 | 0.3415 | 0.043* | |
H12B | 0.0977 | 0.8556 | 0.2729 | 0.043* | |
H12C | 0.0239 | 0.8469 | 0.3073 | 0.043* | |
C13 | 0.06961 (17) | 1.1172 (3) | 0.32315 (15) | 0.0292 (6) | |
H13A | 0.0822 | 1.1976 | 0.3531 | 0.044* | |
H13B | 0.0203 | 1.1193 | 0.3150 | 0.044* | |
H13C | 0.0938 | 1.1271 | 0.2800 | 0.044* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Br1 | 0.02406 (16) | 0.01950 (14) | 0.02495 (16) | −0.00028 (10) | 0.00025 (11) | −0.00428 (10) |
Mn1 | 0.01504 (19) | 0.01594 (19) | 0.01433 (19) | 0.00004 (14) | 0.00055 (14) | 0.00107 (14) |
O1 | 0.0163 (9) | 0.0198 (9) | 0.0163 (9) | 0.0007 (7) | 0.0000 (7) | 0.0034 (7) |
N1 | 0.0159 (11) | 0.0200 (10) | 0.0171 (10) | −0.0006 (8) | 0.0028 (8) | 0.0006 (8) |
N2 | 0.0225 (11) | 0.0224 (11) | 0.0157 (10) | −0.0013 (9) | 0.0004 (9) | −0.0004 (8) |
N3 | 0.0287 (13) | 0.0214 (11) | 0.0174 (11) | −0.0018 (10) | 0.0021 (9) | 0.0028 (9) |
N4 | 0.0151 (10) | 0.0185 (10) | 0.0201 (11) | 0.0002 (8) | −0.0001 (8) | 0.0013 (8) |
N5 | 0.0203 (11) | 0.0189 (11) | 0.0203 (11) | 0.0020 (9) | 0.0035 (9) | 0.0007 (9) |
N6 | 0.0278 (13) | 0.0217 (11) | 0.0187 (11) | 0.0025 (9) | −0.0007 (10) | 0.0020 (9) |
C1 | 0.0183 (13) | 0.0201 (12) | 0.0175 (12) | 0.0029 (10) | 0.0036 (10) | −0.0023 (10) |
C2 | 0.0319 (16) | 0.0221 (13) | 0.0230 (14) | −0.0041 (11) | 0.0011 (12) | −0.0019 (11) |
C3 | 0.0268 (15) | 0.0368 (16) | 0.0225 (14) | 0.0046 (12) | −0.0032 (12) | −0.0050 (12) |
C4 | 0.0430 (19) | 0.0316 (16) | 0.0201 (14) | −0.0015 (13) | 0.0040 (13) | 0.0070 (12) |
C5 | 0.0302 (16) | 0.0219 (13) | 0.0311 (16) | −0.0022 (11) | −0.0009 (13) | −0.0001 (12) |
C6 | 0.0155 (12) | 0.0227 (13) | 0.0231 (13) | −0.0028 (10) | 0.0023 (10) | 0.0036 (10) |
C7 | 0.0153 (12) | 0.0235 (13) | 0.0265 (14) | 0.0004 (10) | 0.0000 (10) | 0.0023 (11) |
C8 | 0.0163 (12) | 0.0221 (13) | 0.0222 (13) | −0.0008 (10) | −0.0026 (10) | 0.0018 (10) |
C9 | 0.0144 (12) | 0.0194 (12) | 0.0202 (13) | 0.0050 (10) | −0.0003 (10) | −0.0011 (10) |
C10 | 0.0251 (14) | 0.0191 (13) | 0.0266 (14) | −0.0009 (11) | −0.0027 (11) | −0.0020 (11) |
C11 | 0.0260 (15) | 0.0211 (13) | 0.0313 (15) | −0.0038 (11) | 0.0087 (12) | −0.0013 (11) |
C12 | 0.0333 (16) | 0.0311 (15) | 0.0214 (14) | −0.0048 (12) | −0.0018 (12) | −0.0014 (12) |
C13 | 0.0375 (17) | 0.0315 (15) | 0.0187 (13) | 0.0051 (13) | 0.0008 (12) | 0.0081 (11) |
Br1—Mn1 | 2.7391 (6) | C3—H3C | 0.9800 |
Mn1—O1 | 1.8188 (18) | C4—H4A | 0.9800 |
Mn1—O1i | 1.8235 (18) | C4—H4B | 0.9800 |
Mn1—N1 | 2.080 (2) | C4—H4C | 0.9800 |
Mn1—N4 | 2.080 (2) | C5—H5A | 0.9800 |
Mn1—Mn1i | 2.7068 (9) | C5—H5B | 0.9800 |
O1—Mn1i | 1.8236 (18) | C5—H5C | 0.9800 |
N1—C1 | 1.301 (3) | C6—C7 | 1.514 (4) |
N1—C6 | 1.474 (3) | C6—H6A | 0.9900 |
N2—C1 | 1.362 (3) | C6—H6B | 0.9900 |
N2—C2 | 1.448 (3) | C7—C8 | 1.510 (4) |
N2—C3 | 1.455 (4) | C7—H7A | 0.9900 |
N3—C1 | 1.357 (3) | C7—H7B | 0.9900 |
N3—C5 | 1.444 (4) | C8—H8A | 0.9900 |
N3—C4 | 1.450 (4) | C8—H8B | 0.9900 |
N4—C9 | 1.311 (3) | C10—H10A | 0.9800 |
N4—C8 | 1.468 (3) | C10—H10B | 0.9800 |
N5—C9 | 1.346 (4) | C10—H10C | 0.9800 |
N5—C10 | 1.442 (3) | C11—H11A | 0.9800 |
N5—C11 | 1.447 (3) | C11—H11B | 0.9800 |
N6—C9 | 1.363 (3) | C11—H11C | 0.9800 |
N6—C12 | 1.440 (4) | C12—H12A | 0.9800 |
N6—C13 | 1.445 (4) | C12—H12B | 0.9800 |
C2—H2A | 0.9800 | C12—H12C | 0.9800 |
C2—H2B | 0.9800 | C13—H13A | 0.9800 |
C2—H2C | 0.9800 | C13—H13B | 0.9800 |
C3—H3A | 0.9800 | C13—H13C | 0.9800 |
C3—H3B | 0.9800 | ||
O1—Mn1—O1i | 84.00 (8) | N3—C5—H5B | 109.5 |
O1—Mn1—N1 | 167.18 (8) | H5A—C5—H5B | 109.5 |
O1i—Mn1—N1 | 91.89 (8) | N3—C5—H5C | 109.5 |
O1—Mn1—N4 | 93.15 (8) | H5A—C5—H5C | 109.5 |
O1i—Mn1—N4 | 167.96 (8) | H5B—C5—H5C | 109.5 |
N1—Mn1—N4 | 88.36 (9) | N1—C6—C7 | 110.6 (2) |
O1—Mn1—Br1 | 99.81 (6) | N1—C6—H6A | 109.5 |
O1i—Mn1—Br1 | 101.45 (6) | C7—C6—H6A | 109.5 |
N1—Mn1—Br1 | 92.90 (6) | N1—C6—H6B | 109.5 |
N4—Mn1—Br1 | 90.56 (6) | C7—C6—H6B | 109.5 |
Mn1—O1—Mn1i | 96.00 (8) | H6A—C6—H6B | 108.1 |
C1—N1—C6 | 118.0 (2) | C8—C7—C6 | 114.4 (2) |
C1—N1—Mn1 | 120.79 (18) | C8—C7—H7A | 108.7 |
C6—N1—Mn1 | 117.94 (17) | C6—C7—H7A | 108.7 |
C1—N2—C2 | 119.7 (2) | C8—C7—H7B | 108.7 |
C1—N2—C3 | 121.2 (2) | C6—C7—H7B | 108.7 |
C2—N2—C3 | 113.4 (2) | H7A—C7—H7B | 107.6 |
C1—N3—C5 | 120.9 (2) | N4—C8—C7 | 111.2 (2) |
C1—N3—C4 | 123.6 (2) | N4—C8—H8A | 109.4 |
C5—N3—C4 | 115.5 (2) | C7—C8—H8A | 109.4 |
C9—N4—C8 | 117.3 (2) | N4—C8—H8B | 109.4 |
C9—N4—Mn1 | 120.79 (18) | C7—C8—H8B | 109.4 |
C8—N4—Mn1 | 118.13 (16) | H8A—C8—H8B | 108.0 |
C9—N5—C10 | 121.0 (2) | N4—C9—N5 | 120.7 (2) |
C9—N5—C11 | 121.9 (2) | N4—C9—N6 | 122.9 (2) |
C10—N5—C11 | 113.9 (2) | N5—C9—N6 | 116.4 (2) |
C9—N6—C12 | 121.1 (2) | N5—C10—H10A | 109.5 |
C9—N6—C13 | 123.0 (2) | N5—C10—H10B | 109.5 |
C12—N6—C13 | 115.9 (2) | H10A—C10—H10B | 109.5 |
N1—C1—N3 | 123.5 (2) | N5—C10—H10C | 109.5 |
N1—C1—N2 | 120.6 (2) | H10A—C10—H10C | 109.5 |
N3—C1—N2 | 115.8 (2) | H10B—C10—H10C | 109.5 |
N2—C2—H2A | 109.5 | N5—C11—H11A | 109.5 |
N2—C2—H2B | 109.5 | N5—C11—H11B | 109.5 |
H2A—C2—H2B | 109.5 | H11A—C11—H11B | 109.5 |
N2—C2—H2C | 109.5 | N5—C11—H11C | 109.5 |
H2A—C2—H2C | 109.5 | H11A—C11—H11C | 109.5 |
H2B—C2—H2C | 109.5 | H11B—C11—H11C | 109.5 |
N2—C3—H3A | 109.5 | N6—C12—H12A | 109.5 |
N2—C3—H3B | 109.5 | N6—C12—H12B | 109.5 |
H3A—C3—H3B | 109.5 | H12A—C12—H12B | 109.5 |
N2—C3—H3C | 109.5 | N6—C12—H12C | 109.5 |
H3A—C3—H3C | 109.5 | H12A—C12—H12C | 109.5 |
H3B—C3—H3C | 109.5 | H12B—C12—H12C | 109.5 |
N3—C4—H4A | 109.5 | N6—C13—H13A | 109.5 |
N3—C4—H4B | 109.5 | N6—C13—H13B | 109.5 |
H4A—C4—H4B | 109.5 | H13A—C13—H13B | 109.5 |
N3—C4—H4C | 109.5 | N6—C13—H13C | 109.5 |
H4A—C4—H4C | 109.5 | H13A—C13—H13C | 109.5 |
H4B—C4—H4C | 109.5 | H13B—C13—H13C | 109.5 |
N3—C5—H5A | 109.5 | ||
O1i—Mn1—O1—Mn1i | 0.0 | C4—N3—C1—N1 | −147.6 (3) |
N1—Mn1—O1—Mn1i | 71.8 (4) | C5—N3—C1—N2 | −150.0 (3) |
N4—Mn1—O1—Mn1i | 168.26 (9) | C4—N3—C1—N2 | 30.3 (4) |
Br1—Mn1—O1—Mn1i | −100.62 (7) | C2—N2—C1—N1 | 17.6 (4) |
O1—Mn1—N1—C1 | −58.7 (5) | C3—N2—C1—N1 | −134.1 (3) |
O1i—Mn1—N1—C1 | 12.3 (2) | C2—N2—C1—N3 | −160.4 (2) |
N4—Mn1—N1—C1 | −155.7 (2) | C3—N2—C1—N3 | 48.0 (3) |
Br1—Mn1—N1—C1 | 113.8 (2) | C1—N1—C6—C7 | 138.4 (2) |
O1—Mn1—N1—C6 | 142.1 (3) | Mn1—N1—C6—C7 | −61.8 (3) |
O1i—Mn1—N1—C6 | −146.92 (18) | N1—C6—C7—C8 | 69.5 (3) |
N4—Mn1—N1—C6 | 45.12 (18) | C9—N4—C8—C7 | −140.8 (2) |
Br1—Mn1—N1—C6 | −45.36 (18) | Mn1—N4—C8—C7 | 60.9 (3) |
O1—Mn1—N4—C9 | −9.4 (2) | C6—C7—C8—N4 | −69.2 (3) |
O1i—Mn1—N4—C9 | 66.5 (5) | C8—N4—C9—N5 | 147.5 (2) |
N1—Mn1—N4—C9 | 157.9 (2) | Mn1—N4—C9—N5 | −54.7 (3) |
Br1—Mn1—N4—C9 | −109.2 (2) | C8—N4—C9—N6 | −30.5 (4) |
O1—Mn1—N4—C8 | 148.21 (19) | Mn1—N4—C9—N6 | 127.3 (2) |
O1i—Mn1—N4—C8 | −135.9 (4) | C10—N5—C9—N4 | −20.4 (4) |
N1—Mn1—N4—C8 | −44.54 (19) | C11—N5—C9—N4 | 138.2 (3) |
Br1—Mn1—N4—C8 | 48.34 (18) | C10—N5—C9—N6 | 157.8 (2) |
C6—N1—C1—N3 | 32.9 (4) | C11—N5—C9—N6 | −43.7 (4) |
Mn1—N1—C1—N3 | −126.3 (2) | C12—N6—C9—N4 | −35.3 (4) |
C6—N1—C1—N2 | −144.9 (2) | C13—N6—C9—N4 | 143.8 (3) |
Mn1—N1—C1—N2 | 55.9 (3) | C12—N6—C9—N5 | 146.6 (3) |
C5—N3—C1—N1 | 32.1 (4) | C13—N6—C9—N5 | −34.3 (4) |
Symmetry code: (i) −x+1/2, −y+3/2, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
C11—H11C···Br1ii | 0.98 | 2.89 | 3.754 (3) | 148 |
Symmetry code: (ii) x, y+1, z. |
Experimental details
Crystal data | |
Chemical formula | [Mn2Br2O2(C13H30N6)2] |
Mr | 842.56 |
Crystal system, space group | Monoclinic, C2/c |
Temperature (K) | 120 |
a, b, c (Å) | 19.592 (4), 9.2077 (17), 19.767 (4) |
β (°) | 90.03 (1) |
V (Å3) | 3566.0 (11) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 2.99 |
Crystal size (mm) | 0.43 × 0.40 × 0.38 |
Data collection | |
Diffractometer | Bruker SMART CCD area-detector |
Absorption correction | Multi-scan (SADABS; Bruker, 2002) |
Tmin, Tmax | 0.290, 0.322 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 16870, 4242, 3584 |
Rint | 0.038 |
(sin θ/λ)max (Å−1) | 0.658 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.037, 0.098, 1.04 |
No. of reflections | 4242 |
No. of parameters | 199 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.85, −0.43 |
Computer programs: SMART (Bruker, 2002), SAINT (Bruker, 2002), SAINT, SHELXTL (Bruker, 2002), SHELXTL.
Br1—Mn1 | 2.7391 (6) | N1—C1 | 1.301 (3) |
Mn1—O1 | 1.8188 (18) | N2—C1 | 1.362 (3) |
Mn1—O1i | 1.8235 (18) | N3—C1 | 1.357 (3) |
Mn1—N1 | 2.080 (2) | N4—C9 | 1.311 (3) |
Mn1—N4 | 2.080 (2) | N5—C9 | 1.346 (4) |
Mn1—Mn1i | 2.7068 (9) | N6—C9 | 1.363 (3) |
O1—Mn1—O1i | 84.00 (8) | O1—Mn1—Br1 | 99.81 (6) |
O1—Mn1—N1 | 167.18 (8) | O1i—Mn1—Br1 | 101.45 (6) |
O1i—Mn1—N1 | 91.89 (8) | N1—Mn1—Br1 | 92.90 (6) |
O1—Mn1—N4 | 93.15 (8) | N4—Mn1—Br1 | 90.56 (6) |
O1i—Mn1—N4 | 167.96 (8) | Mn1—O1—Mn1i | 96.00 (8) |
N1—Mn1—N4 | 88.36 (9) |
Symmetry code: (i) −x+1/2, −y+3/2, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
C11—H11C···Br1ii | 0.98 | 2.89 | 3.754 (3) | 147.6 |
Symmetry code: (ii) x, y+1, z. |
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Since evidence was found that an oxo-bridged manganese cluster participates significantly in the water oxidation process of photosystem II the research and synthesis of oxo-complexes, which contain manganese atoms in high oxidation states of +III or +IV, have become of considerable interest in bioinorganic chemistry (Mukhopadhyay et al., 2004). Recently, a heterocuban oxo-bridged manganese cluster was probably identify as the oxgen-evolving center (OEC) which catalyzes one of the most thermodynamically demanding reactions in biology: the photoinduced oxidation of water (Ferreira et al., 2004). As well the occurrence of manganese hydroxo- and oxo-complexes in the active centres of superoxiddismutases or katalases and the attempt to understand the catalytic processes in these metalloproteins create a need for small biological relevant modell complexes (Wu et al., 2004). In search of bifunctional ligands able to stabilize unusually high metal oxidation states, we have extended our studies to guanidyl-type systems with N-donor functions. The first derivative, the ligand bis(tetramethylguanidino)propylene (btmgp) and its complexes with copper, iron, nickel, lithium, palladium and cobalt have recently been investigated (Harmjanz, 1997; Waden, 1999; Pohl et al., 2000; Schneider, 2000; Heuwing, 2004).
We have now examined the reaction behaviour of the complex [MnBr2(btmgp)] (II) containing the ligand bis(tetra-methylguanidino)propylene (btmgp), towards molecular oxygen which leads to the title complex (I) with distorted square pyramidal coordination of the manganese atoms (Figure 1). There are many examples of bis(µ-oxo)-dimanganese complexes of Mn(III,IV) and Mn(IV,IV) species. However, dimanganese(III,III) species are rare, only a few examples are noted in literature and no compound with a MnIII2O2 core, a bidentate imin-donor ligand and two terminal co-ligands is found in the CSD (Allen, 2002) to date.
There are only few examples of the dimanganese(III,III) species with tetradentate N-donor ligands and octahedrally coordinated manganese centres. The geometric centre of (I) lies on a crystallographic inversion centre and the resulting Mn2O2 core is thus strictly planar. The distance of the Mn atom to the N2O2 plane is 0.207 (1) Å and the nonbonding Mn–Mn distance is 2.7068 (9) Å. The Mn–O and Mn–N bond lengths (Table 1) are comparable with those from other characterized MnIII2O2 complexes that range from 1.787 (6) to 1.863 (8) and 2.084 (6) to 2.468 (10) Å, respectively (Goodson & Hodgson, 1989; Goodson et al., 1990; Kitajima et al., 1991; Glerup et al., 1994). Cell packing (Figure 2) exhibits C–H···Br intermolecular hydrogen bonds (see table) that link molecules to endless chains along [010].