supplementary materials


HTML versionpdf versioncif file3d viewstructure factorssupplementary materialsCIF check reportsimilar papers Open access

ff2002 scheme

Acta Cryst. (2011). E67, m514    [ doi:10.1107/S1600536811011202 ]

Tetrakis[[mu]-N,N'-bis(4-bromophenyl)formamidinato-[kappa]2N:N']dimolybdenum(II) tetrahydrofuran solvate

L.-J. Han

Abstract top

The title complex, [Mo2(C13H9N2Br2)4]·C4H8O, contains a quadruply bonded Mo24+ unit equatorially coordinated by four N,N'-bis(4-bromophenyl)formamidinate ligands, forming a dimetal paddlewheel complex. The centroid of the Mo-Mo bond is located on a special position with 2/m symmetry. In the crystal, complex molecules are linked by Br...Br interactions [3.7049 (10) Å]. The disordered solvent molecule could not be satisfactorily modelled and was therefore eliminated from the final refinement.

Comment top

One of the main interests of crystal engineering is the study of intermolecular interactions and their utilization in supramolecular synthesis (Desiraju 1995; Desiraju 2001; Brammer 2004). These interactions range from strong forces, e.g., classical hydrogen bonds, to weaker ones, e.g., halogen···halogen interactions. The nature of the halogen···halogen interactions has been studied both through extensive crystallographic investigation and using ab initio calculations(Domercq et al.,2001; Espallargas et al., 2006). Here we report intermolecular Br···Br interactions in the crystal structure Mo2(C13H9N2Br2)4.THF.

The molecular structure of the title compound is shown in Fig.1. The molecule of Mo2(C13H9N2Br2)4 (I) occupies a special position on an inversion center, and the Mo—Mo distance is 2.1263 (13) Å, which is in the range of dimolybdenum quadruple bonds. Bromine atoms participate in short contacts (3.7049 (10) Å) linking the molecules of (I) into planes. This value is significantly shorter than van der Waals contact distance (3.90 Å) (Reddy et al., 1996; Fujiwara et al., 2006).

Related literature top

For the nature of halogen–halogen interactions, see: Domercq et al. (2001); Espallargas et al. (2006). For Br···Br interactions, see: Fujiwara et al. (2006); Reddy et al. (1996). For the use of intermolecular interactions in supramolecular synthesis, see: Brammer (2004); Desiraju (1995, 2001).

Experimental top

A mixture yellow Mo2(OOCCH3)4 (0.128 g, 0.300 mmol) and N,N'-bis(4-bromophenyl)formamidinate (0.425 g, 1.20 mmol) was suspended in 20 ml of THF. While stirring, 2.4 ml NaOCH2CH3 solution (0.5 M in ethanol) was added slowly. The colour turned first to red and then to dark red. The reaction was stirred for 5 h at room temperature, and then the volume of the solvent was reduced to about 3 ml under reduced pressure. The residue was washed with distilled water(3×10 ml) and ethanol (8 ml) and dried under vacuum. The yellow solid was dissolved in THF (15 ml) and the solution was layered with hexanes. Yellow block-shaped crystals formed after several days. Yield: 0.342 g (71%). 1HNMR(CDCl3, p.p.m.): 8.41(s, 4H, –NCHN–), 7.10(d, 16H, aromatic), 6.06(d, 16H, aromatic). Anal. Calcd. C52H36Mo2N8Br8: C, 38.94; H, 2.26; N, 6.99; Found: C, 38.78; H, 2.17; N, 7.08.

Refinement top

H atoms were positioned geometrically with C—H = 0.93, 0.97 and 0.96 Å, for aromatic, methylene, and methyl H atoms, respectively, and constrained to ride on their parent atoms, with Uiso(H) = xUeq(C), where x = 1.5 for methyl H and x = 1.2 for aromatic H atoms.

A search for solvent-accessible voids in the crystal structure using PLATON (Spek, 2009) showed a potential solvent volume of 829.4 Å3 and subsequent application of SQUEEZE procedures showed four relevant voids each with a solvent-accessible volume of 207 Å3 . The SQUEEZE procedure was used to eliminate the contribution of the electron density in the solvent region from the intensity data, and the solvent-free model was employed in the final refinement.

Computing details top

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 20098).

Figures top
[Figure 1] Fig. 1. Molecular structure of the title compound drawn with displacement ellipsoids at the 30% probability level. All hydrogen atoms have been omitted for clarity. Atoms with suffix A are generated by the symmetry operation(-x + 1/2, -y + 1/2, -z).
[Figure 2] Fig. 2. Part of a two-dimensional plane of the title compound. Br···Br interactions are drawn with blue dashed lines.
Tetrakis[µ-N,N'-bis(4-bromophenyl) formamidinato-κ2N:N']dimolybdenum(II) tetrahydrofuran solvate top
Crystal data top
[Mo2(C13H9N2Br2)4]·C4H8OF(000) = 3072
Mr = 1604.05Dx = 1.730 Mg m−3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 3824 reflections
a = 21.795 (4) Åθ = 2.6–27.4°
b = 10.077 (2) ŵ = 5.64 mm−1
c = 29.967 (6) ÅT = 293 K
β = 110.67 (3)°Block, yellow
V = 6158 (2) Å30.15 × 0.13 × 0.10 mm
Z = 4
Data collection top
BRUKER SMART 1000
diffractometer		5995 independent reflections
Radiation source: fine-focus sealed tube3563 reflections with I > 2σ(I)
graphiteRint = 0.119
ω–scanθmax = 26.0°, θmin = 3.4°
Absorption correction: multi-scan
(SADABS; Sheldrick, 2004)		h = −26→26
Tmin = 0.429, Tmax = 0.569k = −11→12
25098 measured reflectionsl = −36→36
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)] = 0.055H-atom parameters constrained
wR(F2) = 0.151 w = 1/[σ2(Fo2) + (0.0563P)2]
where P = (Fo2 + 2Fc2)/3
S = 1.01(Δ/σ)max < 0.001
5995 reflectionsΔρmax = 1.09 e Å−3
317 parametersΔρmin = −1.11 e Å−3
0 restraintsExtinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.00036 (7)
Crystal data top
[Mo2(C13H9N2Br2)4]·C4H8OV = 6158 (2) Å3
Mr = 1604.05Z = 4
Monoclinic, C2/cMo Kα radiation
a = 21.795 (4) ŵ = 5.64 mm−1
b = 10.077 (2) ÅT = 293 K
c = 29.967 (6) Å0.15 × 0.13 × 0.10 mm
β = 110.67 (3)°
Data collection top
BRUKER SMART 1000
diffractometer		5995 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2004)		3563 reflections with I > 2σ(I)
Tmin = 0.429, Tmax = 0.569Rint = 0.119
25098 measured reflectionsθmax = 26.0°
Refinement top
R[F2 > 2σ(F2)] = 0.055H-atom parameters constrained
wR(F2) = 0.151Δρmax = 1.09 e Å−3
S = 1.01Δρmin = −1.11 e Å−3
5995 reflectionsAbsolute structure: ?
317 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
Special details top

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 (Å2) top
xyzUiso*/Ueq
Mo10.28396 (3)0.20871 (5)0.031782 (19)0.0376 (2)
N10.2149 (3)0.1089 (5)−0.07230 (18)0.0397 (13)
N20.2911 (3)0.0167 (4)−0.00225 (18)0.0385 (13)
N30.3695 (3)0.2759 (5)0.01561 (19)0.0404 (13)
N40.2950 (3)0.3690 (5)−0.05383 (18)0.0405 (13)
Br10.05852 (5)0.01976 (10)−0.28619 (3)0.0768 (3)
Br20.49853 (4)−0.41859 (7)0.08672 (3)0.0659 (3)
Br30.64761 (5)0.06765 (10)0.13147 (4)0.0836 (3)
Br40.23690 (6)0.65632 (11)−0.24584 (3)0.0954 (4)
C10.2551 (4)0.0100 (6)−0.0494 (2)0.0425 (16)
H1A0.2583−0.0652−0.06640.051*
C20.3574 (4)0.3392 (6)−0.0260 (2)0.0438 (16)
H2A0.39190.3628−0.03570.053*
C110.1773 (3)0.0879 (6)−0.1214 (2)0.0380 (15)
C120.1655 (4)0.1926 (7)−0.1543 (2)0.0535 (19)
H12A0.18050.2772−0.14340.064*
C130.1316 (4)0.1730 (7)−0.2030 (3)0.061 (2)
H13A0.12600.2429−0.22430.073*
C140.1062 (4)0.0477 (8)−0.2194 (3)0.057 (2)
C150.1144 (4)−0.0577 (7)−0.1874 (3)0.058 (2)
H15A0.0977−0.1413−0.19830.070*
C160.1481 (4)−0.0353 (7)−0.1390 (3)0.0530 (19)
H16A0.1515−0.1041−0.11760.064*
C210.3353 (3)−0.0897 (5)0.0191 (2)0.0360 (14)
C220.3289 (4)−0.2199 (6)−0.0001 (2)0.0482 (18)
H22A0.2927−0.2411−0.02680.058*
C230.3763 (4)−0.3170 (6)0.0208 (3)0.0543 (19)
H23A0.3713−0.40210.00800.065*
C240.4313 (4)−0.2864 (6)0.0608 (3)0.0467 (17)
C250.4366 (3)−0.1634 (6)0.0815 (2)0.0451 (17)
H25A0.4722−0.14420.10890.054*
C260.3889 (4)−0.0670 (6)0.0615 (2)0.0472 (18)
H26A0.39250.01470.07670.057*
C310.4360 (3)0.2377 (6)0.0422 (2)0.0401 (15)
C320.4763 (4)0.1811 (6)0.0178 (2)0.0462 (17)
H32A0.46070.1762−0.01530.055*
C330.5399 (4)0.1330 (7)0.0446 (3)0.0512 (18)
H33A0.56620.09700.02910.061*
C340.5629 (4)0.1401 (7)0.0945 (3)0.0513 (18)
C350.5243 (4)0.1974 (6)0.1187 (3)0.0514 (19)
H35A0.54030.20400.15180.062*
C360.4613 (4)0.2443 (6)0.0918 (2)0.0490 (18)
H36A0.43570.28100.10770.059*
C410.2845 (3)0.4385 (6)−0.0982 (2)0.0406 (16)
C420.2423 (4)0.5467 (6)−0.1095 (2)0.0527 (19)
H42A0.22310.5759−0.08810.063*
C430.2285 (4)0.6121 (7)−0.1536 (3)0.064 (2)
H43A0.20040.6848−0.16120.077*
C440.2570 (4)0.5676 (7)−0.1857 (3)0.060 (2)
C450.2992 (4)0.4573 (7)−0.1745 (3)0.060 (2)
H45A0.31760.4271−0.19630.072*
C460.3135 (4)0.3926 (7)−0.1302 (2)0.0509 (18)
H46A0.34190.3204−0.12240.061*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Mo10.0420 (4)0.0429 (3)0.0298 (3)0.0039 (2)0.0151 (3)−0.0015 (2)
N10.042 (4)0.046 (3)0.034 (3)0.001 (2)0.016 (3)−0.004 (2)
N20.042 (4)0.039 (3)0.037 (3)0.003 (2)0.016 (3)−0.002 (2)
N30.035 (3)0.049 (3)0.039 (3)0.004 (2)0.015 (3)−0.001 (2)
N40.045 (4)0.046 (3)0.031 (3)0.006 (2)0.014 (3)0.006 (2)
Br10.0584 (6)0.1298 (8)0.0361 (5)−0.0046 (5)0.0089 (4)−0.0152 (4)
Br20.0648 (6)0.0618 (5)0.0715 (6)0.0196 (4)0.0245 (5)0.0237 (4)
Br30.0522 (6)0.1145 (8)0.0780 (7)0.0227 (5)0.0152 (5)0.0185 (5)
Br40.1135 (10)0.1272 (8)0.0507 (6)0.0062 (7)0.0352 (6)0.0316 (5)
C10.051 (5)0.040 (3)0.038 (4)−0.001 (3)0.017 (3)−0.011 (3)
C20.052 (5)0.045 (3)0.035 (4)0.005 (3)0.017 (4)0.000 (3)
C110.037 (4)0.052 (4)0.028 (3)0.000 (3)0.014 (3)−0.009 (3)
C120.060 (5)0.049 (4)0.044 (4)−0.008 (3)0.010 (4)0.000 (3)
C130.069 (6)0.065 (5)0.045 (4)−0.011 (4)0.017 (4)0.006 (4)
C140.042 (5)0.095 (6)0.033 (4)0.003 (4)0.011 (4)−0.005 (4)
C150.056 (6)0.057 (4)0.052 (5)0.002 (4)0.006 (4)−0.012 (4)
C160.051 (5)0.059 (4)0.044 (4)0.002 (3)0.011 (4)0.001 (3)
C210.035 (4)0.042 (3)0.033 (3)0.003 (3)0.015 (3)0.000 (3)
C220.046 (5)0.044 (4)0.048 (4)0.000 (3)0.008 (4)−0.003 (3)
C230.053 (5)0.045 (4)0.066 (5)0.002 (3)0.023 (4)−0.005 (4)
C240.049 (5)0.044 (4)0.050 (4)−0.003 (3)0.022 (4)0.010 (3)
C250.041 (5)0.046 (4)0.039 (4)−0.004 (3)0.003 (3)−0.001 (3)
C260.057 (5)0.038 (3)0.044 (4)−0.001 (3)0.015 (4)−0.004 (3)
C310.037 (4)0.049 (4)0.041 (4)0.001 (3)0.022 (3)−0.001 (3)
C320.045 (5)0.056 (4)0.038 (4)0.004 (3)0.014 (4)−0.002 (3)
C330.055 (5)0.057 (4)0.048 (4)−0.005 (3)0.026 (4)0.000 (3)
C340.040 (5)0.059 (4)0.060 (5)−0.002 (3)0.023 (4)0.002 (4)
C350.057 (5)0.051 (4)0.043 (4)0.001 (3)0.013 (4)0.000 (3)
C360.052 (5)0.050 (4)0.048 (4)0.004 (3)0.021 (4)−0.010 (3)
C410.040 (4)0.052 (4)0.033 (4)−0.004 (3)0.016 (3)0.005 (3)
C420.065 (6)0.058 (4)0.041 (4)0.006 (4)0.028 (4)0.002 (3)
C430.078 (7)0.056 (4)0.053 (5)0.006 (4)0.018 (5)0.008 (4)
C440.071 (6)0.064 (5)0.042 (4)−0.012 (4)0.015 (4)0.001 (4)
C450.072 (6)0.073 (5)0.049 (5)−0.008 (4)0.039 (5)−0.009 (4)
C460.054 (5)0.064 (4)0.041 (4)0.008 (4)0.025 (4)0.005 (3)
Geometric parameters (Å, °) top
Mo1—Mo1i2.1263 (13)C21—C261.410 (9)
Mo1—N32.192 (5)C21—C221.419 (8)
Mo1—N4i2.195 (5)C22—C231.400 (9)
Mo1—N1i2.198 (5)C22—H22A0.9300
Mo1—N22.218 (5)C23—C241.398 (10)
N1—C11.345 (8)C23—H23A0.9300
N1—C111.424 (7)C24—C251.372 (9)
N1—Mo1i2.198 (5)C25—C261.395 (9)
N2—C11.353 (8)C25—H25A0.9300
N2—C211.432 (7)C26—H26A0.9300
N3—C21.341 (8)C31—C361.393 (9)
N3—C311.439 (8)C31—C321.444 (9)
N4—C21.353 (8)C32—C331.419 (9)
N4—C411.448 (7)C32—H32A0.9300
N4—Mo1i2.195 (5)C33—C341.401 (9)
Br1—C141.924 (7)C33—H33A0.9300
Br2—C241.929 (7)C34—C351.413 (10)
Br3—C341.930 (7)C35—C361.406 (9)
Br4—C441.919 (7)C35—H35A0.9300
C1—H1A0.9300C36—H36A0.9300
C2—H2A0.9300C41—C421.389 (9)
C11—C121.404 (8)C41—C461.402 (8)
C11—C161.410 (9)C42—C431.411 (9)
C12—C131.398 (9)C42—H42A0.9300
C12—H12A0.9300C43—C441.390 (10)
C13—C141.396 (10)C43—H43A0.9300
C13—H13A0.9300C44—C451.405 (11)
C14—C151.399 (10)C45—C461.412 (9)
C15—C161.393 (9)C45—H45A0.9300
C15—H15A0.9300C46—H46A0.9300
C16—H16A0.9300
Mo1i—Mo1—N393.36 (14)C23—C22—H22A119.5
Mo1i—Mo1—N4i92.14 (14)C21—C22—H22A119.5
N3—Mo1—N4i174.47 (19)C24—C23—C22120.2 (6)
Mo1i—Mo1—N1i92.07 (14)C24—C23—H23A119.9
N3—Mo1—N1i91.09 (19)C22—C23—H23A119.9
N4i—Mo1—N1i89.39 (19)C25—C24—C23119.8 (6)
Mo1i—Mo1—N293.96 (14)C25—C24—Br2120.7 (5)
N3—Mo1—N287.97 (18)C23—C24—Br2119.5 (5)
N4i—Mo1—N290.97 (18)C24—C25—C26120.3 (6)
N1i—Mo1—N2173.9 (2)C24—C25—H25A119.9
C1—N1—C11116.9 (5)C26—C25—H25A119.9
C1—N1—Mo1i117.3 (4)C25—C26—C21121.9 (6)
C11—N1—Mo1i125.8 (4)C25—C26—H26A119.0
C1—N2—C21118.6 (5)C21—C26—H26A119.0
C1—N2—Mo1114.5 (4)C36—C31—N3121.4 (6)
C21—N2—Mo1126.4 (4)C36—C31—C32118.4 (6)
C2—N3—C31118.2 (6)N3—C31—C32120.0 (6)
C2—N3—Mo1116.6 (5)C33—C32—C31119.7 (6)
C31—N3—Mo1124.4 (4)C33—C32—H32A120.1
C2—N4—C41118.2 (6)C31—C32—H32A120.1
C2—N4—Mo1i117.3 (4)C34—C33—C32119.7 (7)
C41—N4—Mo1i124.2 (4)C34—C33—H33A120.1
N1—C1—N2122.0 (5)C32—C33—H33A120.1
N1—C1—H1A119.0C33—C34—C35121.0 (7)
N2—C1—H1A119.0C33—C34—Br3120.1 (6)
N3—C2—N4120.3 (6)C35—C34—Br3118.8 (6)
N3—C2—H2A119.9C36—C35—C34118.7 (7)
N4—C2—H2A119.9C36—C35—H35A120.6
C12—C11—C16116.8 (6)C34—C35—H35A120.6
C12—C11—N1120.7 (6)C31—C36—C35122.3 (7)
C16—C11—N1122.5 (6)C31—C36—H36A118.9
C13—C12—C11121.7 (6)C35—C36—H36A118.9
C13—C12—H12A119.2C42—C41—C46120.8 (6)
C11—C12—H12A119.2C42—C41—N4118.7 (6)
C14—C13—C12119.5 (7)C46—C41—N4120.3 (6)
C14—C13—H13A120.2C41—C42—C43119.9 (6)
C12—C13—H13A120.2C41—C42—H42A120.0
C13—C14—C15120.5 (7)C43—C42—H42A120.0
C13—C14—Br1120.0 (6)C44—C43—C42119.8 (7)
C15—C14—Br1119.5 (6)C44—C43—H43A120.1
C16—C15—C14118.8 (7)C42—C43—H43A120.1
C16—C15—H15A120.6C43—C44—C45120.4 (7)
C14—C15—H15A120.6C43—C44—Br4119.3 (6)
C15—C16—C11122.4 (7)C45—C44—Br4120.3 (6)
C15—C16—H16A118.8C44—C45—C46119.9 (7)
C11—C16—H16A118.8C44—C45—H45A120.1
C26—C21—C22116.5 (6)C46—C45—H45A120.1
C26—C21—N2119.6 (5)C41—C46—C45119.2 (6)
C22—C21—N2123.9 (6)C41—C46—H46A120.4
C23—C22—C21120.9 (7)C45—C46—H46A120.4
Symmetry codes: (i) −x+1/2, −y+1/2, −z.
Table 1
Selected geometric parameters (Å) top
Mo1—Mo1i2.1263 (13)Mo1—N1i2.198 (5)
Mo1—N32.192 (5)Mo1—N22.218 (5)
Mo1—N4i2.195 (5)
Symmetry codes: (i) −x+1/2, −y+1/2, −z.
Acknowledgements top

This work was supported by the National Natural Scientific Foundation of China (No.20741004/B010303).

references
References top

Brammer, L. (2004). Chem. Soc. Rev. 33, 476–489.

Bruker. (2001). SAINT-Plus. Bruker AXS Inc., Madison, Wisconsin, USA.

Bruker. (2004). APEX2. Bruker AXS Inc., Madison, Wisconsin, USA.

Desiraju, G. R. (1995). Angew. Chem. Int. Ed. Engl. 34, 2311–2327.

Desiraju, G. R. (2001). Nature, 412, 397–400.

Domercq, B., Devic, T., Fourmigué, M., Auban-Senzier, P. & Canadell, E. (2001). J. Mater. Chem. 11, 1570–1575.

Espallargas, G. M., Brammer, L. & Sherwood, P. (2006). Angew. Chem. Int. Ed. 45, 435–440.

Fujiwara, H., Hayashi, T., Sugimoto, T., Nakazumi, H., Noguchi, S., Li, L., Yokogawa, K., Yasuzuka, S., Murata, K. & Mori, T. (2006). Inorg. Chem. 45, 5712–5714.

Reddy, D. S., Craig, D. C. & Desiraju, G. R. (1996). J. Am. Chem. Soc. 118, 4090–4093.

Sheldrick, G. M. (2004). SADABS. University of Göttingen, Germany.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Spek, A. L. (2009). Acta Cryst. D65, 148–155.