metal-organic compounds
(η5-Cyclopentadienyl)(N,N-dimethyldithiocarbamato-κ2S,S′)[η4-tetrakis(trifluoromethyl)cyclobutadienyl]molybdenum(IV)
aSchool of Engineering and Physical Sciences, Heriot–Watt University, Edinburgh EH14 4AS, Scotland, and bDepartment of Chemistry, University of Glasgow, Glasgow G12 8QQ, Scotland
*Correspondence e-mail: ken@chem.gla.ac.uk
The title complex, [Mo(C8F12)(C5H5)(C3H6NS2)], contains both a η4-C4(CF3)4 cyclobutadienyl ligand with approximate C4v and a η5-C5H5 cyclopentadienyl ring. The centroids of the rings and the S atoms of a chelating dithiocarbamate ligand define the pseudo-tetrahedral coordination of the Mo atom. The Mo—C(cyclobutadienyl) bond lengths [2.189 (2)–2.211 (2) Å] are unusually short, probably reflecting strong electron withdrawal by the trifluoromethyl groups. The molecules straddle crystallographic mirror planes.
Comment
Complexes with η4-C4R4 cyclobutadienyl ligands are known for many transition metals. For example, nine structures containing the (η4-C4R4)Mo moiety occur in the Cambridge Structural Database (CSD; Version 5.25 of November 2003; Allen, 2002) (structural searches were carried out locally using the QUEST and CONQUEST search programs). In most of these compounds, R = Ph (CSD refcodes GICGUU10, LUJZOF, LUKBAU, LUJZUL, PABPMO, PCBMOC10 and TPCBMO), but an R = p-CH3C6H4 complex (GIQTIJ) and a C4Ph3Me species (COXVIU) have also been characterized (see supplementary data for a list of references). We now describe the structure of the title compound, CpCbMo(S2CNMe2), (I), where Cp = η5-C5H5 and Cb = η4-C4(CF3)4. Compound (I) is the first structural example of a η4-C4(CF3)4 complex of any transition metal.
Molecules of (I) have exact Cs symmetry; atoms Mo1, N1, C1, C3, C8–C11, F4 and F7 all lie on a crystallographic mirror plane in P21m (Fig. 1). The metal coordination is pseudo-tetrahedral, being defined by Cp—Mo—Cb and S—Mo—Si angles of 136.6 (2) and 70.0 (1)° (here Cp and Cb are the centroids of the C5 and C4 rings; symmetry code as in Table 1). The bonding in pseudo-tetrahedral CpCbMoL2 species such as (I) has been reviewed by Curnow et al. (1993), who argue that the Cb ligand is best considered as a dianionic C4R42- six-electron donor isoelectronic with Cp−, making (I) a d2 MoIV complex. The metal lone pair in such complexes occupies a stereochemically active dz2-like orbital, compressing the L—M—L angle. Thus, the Cl—Mo—Cl angle in Cp2MoCl2 (Prout et al., 1974) is 82°, only 12° less acute than the S—Mo—Si angle in (I).
The Mo—S distance in (I) (Table 1) differs by only 0.002 (1) Å from the comparable mean of 2.472 Å in the isoelectronic MoIV cation [Mo(η5-In)2(S2CNEt2)]+ (In is indenyl; Drew et al., 1998). The Mo—C(Cp) bond lengths are also unexceptional and the displacement of the Mo atom from the Cp plane [2.012 (1) Å] is close to the average of 2.008 (1) Å for all CpMo compounds in the CSD. However, (i) variations in Cp ring C—C distances and angles [1.338 (9)–1.391 (4) Å and 105.9 (4)–109.2 (2)°] and (ii) Ueq values of Cp ring C atoms nearly three times that of the Mo atom both suggest substantial libration, possibly even some disorder, of the ring about the Mo—Cp vector.
The Cb ligand deviates only slightly from C4v symmetry. Thus, the ring C—C bond lengths differ by only 0.013 (4) Å. Atoms C7, C9 and C11 are displaced by 0.340 (2), 0.562 (4) and 0.504 (3) Å, respectively, to the opposite side of the C4 ring plane from the Mo atom, probably to relieve intraligand repulsions. Rotation of the C7F3 group from its ideal position by ca 8° is shown by F1—C7—C6—C8 and F1—C7—C6—C10 torsion angles of 84.1 (3) and −67.6 (3)°, respectively. The near equality of the Ueq values for the Mo and the Cb ring C atoms is consistent with the high barrier to libration about the Mo—Cb vector suggested by spectroscopic evidence (Davidson, 1987).
In other (η4-C4R4)Mo complexes the ring C—C bond lengths usually show little variation and their average value of 1.462 (2) Å agrees well with the individual values in (I). In contrast, the ring C—C bond lengths in C4R4 molecules indicate fixed double and single bonds (Irmgartinger et al., 1988, and references therein).
The Mo—C(Cb) bond lengths in (I) vary slightly and are on average 0.08 Å shorter than the mean value of 2.284 (7) Å for other (η4-C4R4)Mo complexes (where R = Me, Ph, etc.). The displacement of the Mo atom from the Cb ring plane in (I) [1.944 (1) Å] is likewise less than the range of 1.995–2.074 Å found in other MoCb complexes.
Curnow et al. (1993) substantiate their view of Cb as a C4R42- dianionic ligand from extended Hückel molecular-orbital (EHMO) calculations, which show that in CpCbMoL2 species much more charge is transferred from Mo to Cb than to Cp. Electron-withdrawing CF3 substituents on the Cb C atoms might be expected to facilitate this transfer and thus to produce the very strong Mo—Cb π bonds found in (I).
Experimental
The preparation and spectroscopic characterization of (I) have been described by Davidson (1987).
Crystal data
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Data collection
Refinement
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The structure was solved by Patterson and Fourier methods. H atoms were located initially in difference maps. In the final SHELXL97 (Sheldrick, 1997) and they were then treated as riding on their parent C atoms [cyclopentadienyl C—H = 0.93 Å, methyl C—H = 0.96 Å and Uiso(H) = 1.3Ueq(C)]. A single parameter defining the orientation of the CH3 group about the N—C bond was refined freely.
the positions of the H atoms were determined by the HFIX instruction inData collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell CAD-4 EXPRESS; data reduction: GX (Mallinson & Muir, 1985); program(s) used to solve structure: GX; program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).
Supporting information
10.1107/S0108270105006086/gd1377sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S0108270105006086/gd1377Isup2.hkl
Supporting information file. DOI: 10.1107/S0108270105006086/gd1377sup3.pdf
Supporting information file. DOI: 10.1107/S0108270105006086/gd1377sup4.pdf
The preparation and spectroscopic characterization of (I) have been described by Davidson (1987).
The structure was solved by Patterson and Fourier methods. Hydrogen atoms were located initially in difference maps. In the final
the positions of hydrogen atoms were determined by the HFIX instruction in SHELXL97 (Sheldrick, 1997) and they then rode on their parent carbon atoms with C5H5 C—H = 0.93 Å, methyl C—H = 0.96 Å and Uiso(H) = 1.3Ueq(C). A single parameter defining the orientation of the CH3 group about the N—C bond was freely refined.Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1984); cell
CAD-4 EXPRESS; data reduction: GX (Mallinson & Muir, 1985); program(s) used to solve structure: GX; program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).Fig. 1. A view of the molecule of (I), showing 20% probability displacement ellipsoids. [Symmetry code: (i) x, 1/2 − y, z.] |
[Mo(C8F12)(C5H5)(C3H6NS2)] | F(000) = 592 |
Mr = 605.32 | Dx = 1.965 Mg m−3 |
Monoclinic, P21/m | Mo Kα radiation, λ = 0.71069 Å |
Hall symbol: -P 2yb | Cell parameters from 25 reflections |
a = 8.918 (1) Å | θ = 8.9–14.6° |
b = 12.185 (1) Å | µ = 0.96 mm−1 |
c = 9.809 (2) Å | T = 295 K |
β = 106.28 (1)° | Prism, yellow |
V = 1023.2 (3) Å3 | 0.54 × 0.45 × 0.28 mm |
Z = 2 |
Enraf–Nonius CAD-4 diffractometer | 2761 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.020 |
Graphite monochromator | θmax = 30.0°, θmin = 2.2° |
non–profiled ω scans | h = 0→12 |
Absorption correction: gaussian Shape of crystal defined by six pairs of parallel faces. | k = 0→17 |
Tmin = 0.730, Tmax = 0.800 | l = −13→13 |
5153 measured reflections | 2 standard reflections every 120 min |
3025 independent reflections | intensity decay: none |
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)] = 0.024 | H-atom parameters constrained |
wR(F2) = 0.069 | w = 1/[σ2(Fo2) + (0.018P)2 + 0.018P] where P = (Fo2 + 2Fc2)/3 |
S = 1.06 | (Δ/σ)max = 0.001 |
3025 reflections | Δρmax = 0.40 e Å−3 |
162 parameters | Δρmin = −0.35 e Å−3 |
0 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0188 (13) |
[Mo(C8F12)(C5H5)(C3H6NS2)] | V = 1023.2 (3) Å3 |
Mr = 605.32 | Z = 2 |
Monoclinic, P21/m | Mo Kα radiation |
a = 8.918 (1) Å | µ = 0.96 mm−1 |
b = 12.185 (1) Å | T = 295 K |
c = 9.809 (2) Å | 0.54 × 0.45 × 0.28 mm |
β = 106.28 (1)° |
Enraf–Nonius CAD-4 diffractometer | 2761 reflections with I > 2σ(I) |
Absorption correction: gaussian Shape of crystal defined by six pairs of parallel faces. | Rint = 0.020 |
Tmin = 0.730, Tmax = 0.800 | 2 standard reflections every 120 min |
5153 measured reflections | intensity decay: none |
3025 independent reflections |
R[F2 > 2σ(F2)] = 0.024 | 0 restraints |
wR(F2) = 0.069 | H-atom parameters constrained |
S = 1.06 | Δρmax = 0.40 e Å−3 |
3025 reflections | Δρmin = −0.35 e Å−3 |
162 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 | ||
Mo1 | 0.10164 (2) | 0.2500 | 0.13424 (2) | 0.03269 (7) | |
S1 | 0.25303 (6) | 0.36636 (4) | 0.01458 (6) | 0.05097 (12) | |
N1 | 0.4076 (3) | 0.2500 | −0.1351 (3) | 0.0618 (7) | |
F1 | 0.2789 (3) | 0.03042 (14) | 0.51023 (16) | 0.0987 (7) | |
F2 | 0.3169 (3) | −0.00554 (14) | 0.3107 (2) | 0.1026 (7) | |
F3 | 0.0885 (2) | −0.00517 (14) | 0.3329 (2) | 0.0955 (6) | |
F4 | 0.5589 (2) | 0.2500 | 0.4734 (3) | 0.0961 (9) | |
F5 | 0.53939 (18) | 0.3361 (2) | 0.2848 (2) | 0.1146 (8) | |
F6 | −0.0979 (2) | 0.16285 (17) | 0.4237 (2) | 0.0884 (5) | |
F7 | 0.0713 (3) | 0.2500 | 0.5844 (2) | 0.0995 (10) | |
C1 | 0.3180 (3) | 0.2500 | −0.0485 (3) | 0.0470 (6) | |
C2 | 0.4575 (3) | 0.1469 (3) | −0.1839 (3) | 0.0880 (10) | |
H2A | 0.5102 | 0.1616 | −0.2549 | 0.114* | |
H2B | 0.3679 | 0.1016 | −0.2237 | 0.114* | |
H2C | 0.5274 | 0.1096 | −0.1052 | 0.114* | |
C3 | −0.0826 (4) | 0.2500 | −0.0847 (4) | 0.0764 (12) | |
H3 | −0.0489 | 0.2500 | −0.1662 | 0.099* | |
C4 | −0.1129 (3) | 0.3411 (2) | −0.0112 (4) | 0.0870 (10) | |
H4 | −0.1050 | 0.4142 | −0.0358 | 0.113* | |
C5 | −0.1556 (3) | 0.3049 (4) | 0.1014 (4) | 0.1114 (17) | |
H5 | −0.1812 | 0.3491 | 0.1689 | 0.145* | |
C6 | 0.20957 (19) | 0.16477 (14) | 0.33535 (17) | 0.0378 (3) | |
C7 | 0.2248 (3) | 0.04708 (17) | 0.3723 (2) | 0.0549 (5) | |
C8 | 0.3148 (3) | 0.2500 | 0.3118 (3) | 0.0373 (4) | |
C9 | 0.4862 (3) | 0.2500 | 0.3359 (4) | 0.0563 (7) | |
C10 | 0.1078 (3) | 0.2500 | 0.3612 (3) | 0.0386 (4) | |
C11 | −0.0064 (4) | 0.2500 | 0.4467 (3) | 0.0582 (7) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Mo1 | 0.03410 (10) | 0.02957 (10) | 0.03542 (11) | 0.000 | 0.01143 (7) | 0.000 |
S1 | 0.0650 (3) | 0.0403 (2) | 0.0546 (3) | −0.0042 (2) | 0.0282 (2) | 0.00671 (19) |
N1 | 0.0491 (13) | 0.099 (2) | 0.0422 (12) | 0.000 | 0.0207 (10) | 0.000 |
F1 | 0.1639 (19) | 0.0582 (9) | 0.0547 (8) | 0.0013 (10) | −0.0014 (10) | 0.0188 (7) |
F2 | 0.1489 (18) | 0.0526 (9) | 0.1235 (16) | 0.0446 (10) | 0.0667 (15) | 0.0170 (9) |
F3 | 0.1058 (13) | 0.0514 (8) | 0.1157 (14) | −0.0289 (9) | 0.0087 (11) | 0.0163 (9) |
F4 | 0.0453 (10) | 0.169 (3) | 0.0649 (13) | 0.000 | −0.0003 (9) | 0.000 |
F5 | 0.0461 (7) | 0.1486 (19) | 0.1439 (18) | −0.0267 (10) | 0.0183 (9) | 0.0584 (15) |
F6 | 0.0833 (10) | 0.1020 (13) | 0.0993 (12) | −0.0288 (10) | 0.0573 (9) | 0.0048 (10) |
F7 | 0.0825 (15) | 0.179 (3) | 0.0455 (10) | 0.000 | 0.0312 (10) | 0.000 |
C1 | 0.0470 (13) | 0.0589 (15) | 0.0382 (11) | 0.000 | 0.0170 (10) | 0.000 |
C2 | 0.0700 (15) | 0.135 (3) | 0.0659 (15) | 0.0159 (17) | 0.0314 (13) | −0.0280 (17) |
C3 | 0.0514 (17) | 0.129 (4) | 0.0409 (14) | 0.000 | 0.0000 (12) | 0.000 |
C4 | 0.0507 (12) | 0.0576 (14) | 0.129 (3) | 0.0119 (11) | −0.0136 (15) | 0.0141 (16) |
C5 | 0.0393 (10) | 0.203 (5) | 0.0824 (18) | 0.0244 (16) | 0.0011 (11) | −0.052 (2) |
C6 | 0.0409 (7) | 0.0340 (7) | 0.0396 (7) | 0.0014 (6) | 0.0131 (6) | 0.0038 (6) |
C7 | 0.0747 (13) | 0.0376 (9) | 0.0505 (10) | 0.0039 (9) | 0.0143 (9) | 0.0077 (8) |
C8 | 0.0328 (10) | 0.0381 (11) | 0.0419 (11) | 0.000 | 0.0116 (8) | 0.000 |
C9 | 0.0357 (12) | 0.074 (2) | 0.0590 (16) | 0.000 | 0.0134 (11) | 0.000 |
C10 | 0.0394 (11) | 0.0415 (11) | 0.0385 (11) | 0.000 | 0.0168 (9) | 0.000 |
C11 | 0.0522 (15) | 0.079 (2) | 0.0519 (15) | 0.000 | 0.0283 (13) | 0.000 |
Mo1—C3 | 2.309 (3) | F7—C11 | 1.334 (4) |
Mo1—C4 | 2.324 (2) | C2—H2A | 0.9600 |
Mo1—C5 | 2.324 (2) | C2—H2B | 0.9600 |
Mo1—C6 | 2.198 (2) | C2—H2C | 0.9600 |
Mo1—C8 | 2.189 (2) | C3—C4 | 1.391 (4) |
Mo1—C10 | 2.211 (2) | C3—H3 | 0.9300 |
Mo1—S1 | 2.4697 (5) | C4—C5 | 1.340 (5) |
S1—C1 | 1.712 (2) | C4—H4 | 0.9300 |
N1—C1 | 1.320 (3) | C5—C5i | 1.338 (9) |
N1—C2 | 1.458 (3) | C5—H5 | 0.9300 |
F1—C7 | 1.319 (2) | C6—C10 | 1.448 (2) |
F2—C7 | 1.314 (3) | C6—C8 | 1.461 (2) |
F3—C7 | 1.330 (3) | C6—C7 | 1.476 (3) |
F4—C9 | 1.323 (4) | C8—C9 | 1.480 (3) |
F5—C9 | 1.308 (3) | C10—C11 | 1.490 (4) |
F6—C11 | 1.320 (2) | ||
C8—Mo1—C6 | 38.90 (6) | H2B—C2—H2C | 109.5 |
C6i—Mo1—C6 | 56.39 (9) | C4—C3—C4i | 105.9 (4) |
C8—Mo1—C10 | 55.12 (9) | C4—C3—Mo1 | 73.10 (17) |
C6—Mo1—C10 | 38.33 (6) | C4i—C3—Mo1 | 73.10 (17) |
C8—Mo1—C3 | 166.59 (11) | C4—C3—H3 | 127.0 |
C6—Mo1—C3 | 148.53 (6) | C4i—C3—H3 | 127.0 |
C10—Mo1—C3 | 138.29 (12) | Mo1—C3—H3 | 118.9 |
C8—Mo1—C5 | 135.55 (9) | C5—C4—C3 | 107.8 (3) |
C6i—Mo1—C5 | 98.94 (9) | C5—C4—Mo1 | 73.25 (17) |
C6—Mo1—C5 | 115.31 (11) | C3—C4—Mo1 | 71.95 (17) |
C10—Mo1—C5 | 83.37 (11) | C5—C4—H4 | 126.1 |
C3—Mo1—C5 | 56.89 (12) | C3—C4—H4 | 126.1 |
C5i—Mo1—C5 | 33.5 (2) | Mo1—C4—H4 | 120.5 |
C8—Mo1—C4i | 150.52 (8) | C5i—C5—C4 | 109.2 (2) |
C6i—Mo1—C4i | 148.74 (11) | C5i—C5—Mo1 | 73.26 (12) |
C6—Mo1—C4i | 113.78 (10) | C4—C5—Mo1 | 73.25 (15) |
C10—Mo1—C4i | 113.68 (12) | C5i—C5—H5 | 125.4 |
C3—Mo1—C4i | 34.95 (10) | C4—C5—H5 | 125.4 |
C5—Mo1—C4i | 56.04 (12) | Mo1—C5—H5 | 119.8 |
C8—Mo1—C4 | 150.52 (8) | C10—C6—C8 | 88.85 (13) |
C6i—Mo1—C4 | 113.78 (10) | C10—C6—C7 | 132.31 (17) |
C6—Mo1—C4 | 148.74 (11) | C8—C6—C7 | 135.27 (17) |
C10—Mo1—C4 | 113.68 (12) | C10—C6—Mo1 | 71.33 (11) |
C3—Mo1—C4 | 34.95 (10) | C8—C6—Mo1 | 70.20 (11) |
C5—Mo1—C4 | 33.50 (13) | C7—C6—Mo1 | 131.78 (13) |
C4i—Mo1—C4 | 57.10 (15) | F2—C7—F1 | 107.5 (2) |
C8—Mo1—S1i | 84.81 (5) | F2—C7—F3 | 105.7 (2) |
C6i—Mo1—S1i | 122.52 (5) | F1—C7—F3 | 105.4 (2) |
C6—Mo1—S1i | 89.72 (5) | F2—C7—C6 | 112.81 (19) |
C10—Mo1—S1i | 128.02 (4) | F1—C7—C6 | 112.54 (18) |
C3—Mo1—S1i | 84.21 (8) | F3—C7—C6 | 112.34 (19) |
C5i—Mo1—S1i | 114.75 (12) | C6—C8—C6i | 90.61 (18) |
C5—Mo1—S1i | 138.53 (8) | C6—C8—C9 | 130.94 (12) |
C4i—Mo1—S1i | 84.24 (9) | C6i—C8—C9 | 130.94 (12) |
C4—Mo1—S1i | 116.64 (11) | C6—C8—Mo1 | 70.89 (11) |
C8—Mo1—S1 | 84.81 (5) | C6i—C8—Mo1 | 70.89 (11) |
C6i—Mo1—S1 | 89.72 (5) | C9—C8—Mo1 | 139.03 (19) |
C6—Mo1—S1 | 122.52 (5) | C10—C8—Mo1 | 63.00 (9) |
C10—Mo1—S1 | 128.02 (4) | F5—C9—F5i | 106.7 (3) |
C3—Mo1—S1 | 84.21 (8) | F5—C9—F4 | 105.31 (19) |
C5i—Mo1—S1 | 138.53 (8) | F5i—C9—F4 | 105.31 (19) |
C5—Mo1—S1 | 114.75 (12) | F5—C9—C8 | 114.08 (17) |
C4i—Mo1—S1 | 116.64 (11) | F5i—C9—C8 | 114.08 (17) |
C4—Mo1—S1 | 84.24 (9) | F4—C9—C8 | 110.6 (2) |
S1i—Mo1—S1 | 70.07 (3) | C6i—C10—C6 | 91.67 (19) |
C1—S1—Mo1 | 88.95 (8) | C6i—C10—C11 | 131.28 (11) |
C1—N1—C2i | 120.46 (16) | C6—C10—C11 | 131.28 (11) |
C1—N1—C2 | 120.46 (16) | C6i—C10—Mo1 | 70.34 (11) |
C2i—N1—C2 | 119.1 (3) | C6—C10—Mo1 | 70.34 (11) |
N1—C1—S1 | 124.06 (7) | C11—C10—Mo1 | 137.6 (2) |
N1—C1—S1i | 124.06 (7) | C8—C10—Mo1 | 61.87 (9) |
S1—C1—S1i | 111.87 (15) | F6—C11—F6i | 107.2 (3) |
N1—C2—H2A | 109.5 | F6—C11—F7 | 107.07 (19) |
N1—C2—H2B | 109.5 | F6i—C11—F7 | 107.07 (19) |
H2A—C2—H2B | 109.5 | F6—C11—C10 | 113.04 (17) |
N1—C2—H2C | 109.5 | F6i—C11—C10 | 113.04 (17) |
H2A—C2—H2C | 109.5 | F7—C11—C10 | 109.1 (3) |
C8—Mo1—S1—C1 | 88.82 (10) | C7—C6—C8—Mo1 | 130.0 (2) |
C6i—Mo1—S1—C1 | 127.47 (10) | C6i—Mo1—C8—C6 | 97.58 (18) |
C6—Mo1—S1—C1 | 78.74 (11) | C10—Mo1—C8—C6 | 48.79 (9) |
C10—Mo1—S1—C1 | 125.71 (11) | C3—Mo1—C8—C6 | −131.21 (9) |
C3—Mo1—S1—C1 | −83.46 (11) | C5i—Mo1—C8—C6 | 24.5 (2) |
C5i—Mo1—S1—C1 | −102.7 (2) | C5—Mo1—C8—C6 | 73.07 (19) |
C5—Mo1—S1—C1 | −132.81 (13) | C4i—Mo1—C8—C6 | −27.4 (3) |
C4i—Mo1—S1—C1 | −70.00 (13) | C4—Mo1—C8—C6 | 125.0 (2) |
C4—Mo1—S1—C1 | −118.59 (13) | S1i—Mo1—C8—C6 | −96.01 (9) |
S1i—Mo1—S1—C1 | 2.47 (10) | S1—Mo1—C8—C6 | −166.41 (9) |
C2i—N1—C1—S1 | −0.2 (4) | C6—Mo1—C8—C6i | −97.58 (18) |
C2—N1—C1—S1 | −179.9 (2) | C10—Mo1—C8—C6i | −48.79 (9) |
C2i—N1—C1—S1i | 179.9 (2) | C3—Mo1—C8—C6i | 131.21 (9) |
C2—N1—C1—S1i | 0.2 (4) | C5i—Mo1—C8—C6i | −73.07 (19) |
Mo1—S1—C1—N1 | 176.5 (3) | C5—Mo1—C8—C6i | −24.5 (2) |
Mo1—S1—C1—S1i | −3.61 (14) | C4i—Mo1—C8—C6i | −125.0 (2) |
C8—Mo1—C3—C4 | −123.47 (19) | C4—Mo1—C8—C6i | 27.4 (3) |
C6i—Mo1—C3—C4 | −8.3 (3) | S1i—Mo1—C8—C6i | 166.41 (9) |
C6—Mo1—C3—C4 | 121.37 (18) | S1—Mo1—C8—C6i | 96.01 (9) |
C10—Mo1—C3—C4 | 56.53 (19) | C6i—Mo1—C8—C9 | −131.21 (9) |
C5i—Mo1—C3—C4 | 76.6 (3) | C6—Mo1—C8—C9 | 131.21 (9) |
C5—Mo1—C3—C4 | 36.4 (2) | C10—Mo1—C8—C9 | 180.0 |
C4i—Mo1—C3—C4 | 113.1 (4) | C3—Mo1—C8—C9 | 0.0 |
S1i—Mo1—C3—C4 | −158.7 (2) | C5i—Mo1—C8—C9 | 155.72 (18) |
S1—Mo1—C3—C4 | −88.22 (19) | C5—Mo1—C8—C9 | −155.72 (18) |
C8—Mo1—C3—C4i | 123.47 (19) | C4i—Mo1—C8—C9 | 103.8 (2) |
C6i—Mo1—C3—C4i | −121.37 (18) | C4—Mo1—C8—C9 | −103.8 (2) |
C6—Mo1—C3—C4i | 8.3 (3) | S1i—Mo1—C8—C9 | 35.202 (14) |
C10—Mo1—C3—C4i | −56.53 (19) | S1—Mo1—C8—C9 | −35.202 (14) |
C5i—Mo1—C3—C4i | −36.4 (2) | C6i—Mo1—C8—C10 | 48.79 (9) |
C5—Mo1—C3—C4i | −76.6 (3) | C6—Mo1—C8—C10 | −48.79 (9) |
C4—Mo1—C3—C4i | −113.1 (4) | C3—Mo1—C8—C10 | 180.0 |
S1i—Mo1—C3—C4i | 88.22 (19) | C5i—Mo1—C8—C10 | −24.28 (18) |
S1—Mo1—C3—C4i | 158.7 (2) | C5—Mo1—C8—C10 | 24.28 (18) |
C4i—C3—C4—C5 | 1.3 (4) | C4i—Mo1—C8—C10 | −76.2 (2) |
Mo1—C3—C4—C5 | −65.0 (2) | C4—Mo1—C8—C10 | 76.2 (2) |
C4i—C3—C4—Mo1 | 66.3 (2) | S1i—Mo1—C8—C10 | −144.798 (14) |
C8—Mo1—C4—C5 | −87.4 (3) | S1—Mo1—C8—C10 | 144.798 (14) |
C6i—Mo1—C4—C5 | −69.0 (2) | C6—C8—C9—F5 | 171.3 (2) |
C6—Mo1—C4—C5 | −5.1 (3) | C6i—C8—C9—F5 | −48.3 (4) |
C10—Mo1—C4—C5 | −27.0 (2) | C10—C8—C9—F5 | −118.5 (2) |
C3—Mo1—C4—C5 | 115.7 (3) | Mo1—C8—C9—F5 | 61.5 (2) |
C5i—Mo1—C4—C5 | 36.4 (3) | C6—C8—C9—F5i | 48.3 (4) |
C4i—Mo1—C4—C5 | 76.8 (2) | C6i—C8—C9—F5i | −171.3 (2) |
S1i—Mo1—C4—C5 | 139.5 (2) | C10—C8—C9—F5i | 118.5 (2) |
S1—Mo1—C4—C5 | −156.2 (2) | Mo1—C8—C9—F5i | −61.5 (2) |
C8—Mo1—C4—C3 | 156.8 (2) | C6—C8—C9—F4 | −70.2 (2) |
C6i—Mo1—C4—C3 | 175.27 (18) | C6i—C8—C9—F4 | 70.2 (2) |
C6—Mo1—C4—C3 | −120.8 (2) | C10—C8—C9—F4 | 0.0 |
C10—Mo1—C4—C3 | −142.69 (18) | Mo1—C8—C9—F4 | 180.0 |
C5i—Mo1—C4—C3 | −79.3 (2) | C8—C6—C10—C6i | 1.05 (19) |
C5—Mo1—C4—C3 | −115.7 (3) | C7—C6—C10—C6i | 161.54 (15) |
C4i—Mo1—C4—C3 | −38.9 (2) | Mo1—C6—C10—C6i | −68.42 (12) |
S1i—Mo1—C4—C3 | 23.8 (2) | C8—C6—C10—C11 | −153.6 (3) |
S1—Mo1—C4—C3 | 88.13 (19) | C7—C6—C10—C11 | 6.9 (4) |
C3—C4—C5—C5i | −0.8 (2) | Mo1—C6—C10—C11 | 136.9 (3) |
Mo1—C4—C5—C5i | −64.9 (2) | C7—C6—C10—C8 | 160.5 (3) |
C3—C4—C5—Mo1 | 64.1 (2) | Mo1—C6—C10—C8 | −69.46 (11) |
C8—Mo1—C5—C5i | −107.85 (14) | C8—C6—C10—Mo1 | 69.46 (11) |
C6i—Mo1—C5—C5i | −123.1 (2) | C7—C6—C10—Mo1 | −130.0 (2) |
C6—Mo1—C5—C5i | −66.2 (2) | C6—C8—C10—C6i | −178.5 (3) |
C10—Mo1—C5—C5i | −88.0 (2) | C9—C8—C10—C6i | 90.73 (13) |
C3—Mo1—C5—C5i | 78.69 (10) | Mo1—C8—C10—C6i | −89.27 (13) |
C4i—Mo1—C5—C5i | 36.47 (13) | C6i—C8—C10—C6 | 178.5 (3) |
C4—Mo1—C5—C5i | 116.7 (2) | C9—C8—C10—C6 | −90.73 (13) |
S1i—Mo1—C5—C5i | 55.6 (3) | Mo1—C8—C10—C6 | 89.27 (13) |
S1—Mo1—C5—C5i | 143.0 (2) | C6—C8—C10—C11 | 90.73 (13) |
C8—Mo1—C5—C4 | 135.42 (17) | C6i—C8—C10—C11 | −90.73 (13) |
C6i—Mo1—C5—C4 | 120.1 (2) | C9—C8—C10—C11 | 0.000 (2) |
C6—Mo1—C5—C4 | 177.07 (19) | Mo1—C8—C10—C11 | 180.000 (2) |
C10—Mo1—C5—C4 | 155.3 (2) | C6—C8—C10—Mo1 | −89.27 (13) |
C3—Mo1—C5—C4 | −38.04 (18) | C6i—C8—C10—Mo1 | 89.27 (13) |
C5i—Mo1—C5—C4 | −116.7 (2) | C9—C8—C10—Mo1 | 180.0 |
C4i—Mo1—C5—C4 | −80.3 (3) | C8—Mo1—C10—C6i | 49.62 (9) |
S1i—Mo1—C5—C4 | −61.1 (3) | C6—Mo1—C10—C6i | 99.23 (19) |
S1—Mo1—C5—C4 | 26.3 (2) | C3—Mo1—C10—C6i | −130.38 (9) |
C8—Mo1—C6—C10 | 95.69 (14) | C5i—Mo1—C10—C6i | −147.24 (15) |
C6i—Mo1—C6—C10 | 47.32 (11) | C5—Mo1—C10—C6i | −113.53 (15) |
C3—Mo1—C6—C10 | −103.8 (2) | C4i—Mo1—C10—C6i | −161.84 (12) |
C5i—Mo1—C6—C10 | −67.21 (16) | C4—Mo1—C10—C6i | −98.93 (13) |
C5—Mo1—C6—C10 | −36.49 (15) | S1i—Mo1—C10—C6i | 96.40 (8) |
C4i—Mo1—C6—C10 | −98.65 (14) | S1—Mo1—C10—C6i | 2.84 (12) |
C4—Mo1—C6—C10 | −33.4 (2) | C8—Mo1—C10—C6 | −49.62 (9) |
S1i—Mo1—C6—C10 | 177.77 (10) | C6i—Mo1—C10—C6 | −99.23 (19) |
S1—Mo1—C6—C10 | 111.80 (9) | C3—Mo1—C10—C6 | 130.38 (9) |
C6i—Mo1—C6—C8 | −48.37 (10) | C5i—Mo1—C10—C6 | 113.53 (15) |
C10—Mo1—C6—C8 | −95.69 (14) | C5—Mo1—C10—C6 | 147.24 (15) |
C3—Mo1—C6—C8 | 160.47 (19) | C4i—Mo1—C10—C6 | 98.93 (13) |
C5i—Mo1—C6—C8 | −162.90 (15) | C4—Mo1—C10—C6 | 161.84 (12) |
C5—Mo1—C6—C8 | −132.17 (14) | S1i—Mo1—C10—C6 | −2.84 (12) |
C4i—Mo1—C6—C8 | 165.66 (13) | S1—Mo1—C10—C6 | −96.40 (8) |
C4—Mo1—C6—C8 | −129.06 (18) | C8—Mo1—C10—C11 | 180.0 |
S1i—Mo1—C6—C8 | 82.08 (9) | C6i—Mo1—C10—C11 | 130.38 (9) |
S1—Mo1—C6—C8 | 16.11 (11) | C6—Mo1—C10—C11 | −130.38 (9) |
C8—Mo1—C6—C7 | −133.7 (2) | C3—Mo1—C10—C11 | 0.0 |
C6i—Mo1—C6—C7 | 177.93 (17) | C5i—Mo1—C10—C11 | −16.85 (12) |
C10—Mo1—C6—C7 | 130.6 (2) | C5—Mo1—C10—C11 | 16.85 (12) |
C3—Mo1—C6—C7 | 26.8 (3) | C4i—Mo1—C10—C11 | −31.46 (8) |
C5i—Mo1—C6—C7 | 63.4 (2) | C4—Mo1—C10—C11 | 31.46 (8) |
C5—Mo1—C6—C7 | 94.1 (2) | S1i—Mo1—C10—C11 | −133.22 (4) |
C4i—Mo1—C6—C7 | 32.0 (2) | S1—Mo1—C10—C11 | 133.22 (4) |
C4—Mo1—C6—C7 | 97.2 (2) | C6i—Mo1—C10—C8 | −49.62 (9) |
S1i—Mo1—C6—C7 | −51.62 (19) | C6—Mo1—C10—C8 | 49.62 (9) |
S1—Mo1—C6—C7 | −117.59 (18) | C3—Mo1—C10—C8 | 180.0 |
C10—C6—C7—F2 | 170.6 (2) | C5i—Mo1—C10—C8 | 163.15 (12) |
C8—C6—C7—F2 | −37.7 (3) | C5—Mo1—C10—C8 | −163.15 (12) |
Mo1—C6—C7—F2 | 67.1 (3) | C4i—Mo1—C10—C8 | 148.54 (8) |
C10—C6—C7—F1 | −67.6 (3) | C4—Mo1—C10—C8 | −148.54 (8) |
C8—C6—C7—F1 | 84.1 (3) | S1i—Mo1—C10—C8 | 46.78 (4) |
Mo1—C6—C7—F1 | −171.05 (16) | S1—Mo1—C10—C8 | −46.78 (4) |
C10—C6—C7—F3 | 51.2 (3) | C6i—C10—C11—F6 | 168.3 (2) |
C8—C6—C7—F3 | −157.1 (2) | C6—C10—C11—F6 | −46.4 (4) |
Mo1—C6—C7—F3 | −52.2 (3) | C8—C10—C11—F6 | −119.0 (2) |
C10—C6—C8—C6i | −1.0 (2) | Mo1—C10—C11—F6 | 61.0 (2) |
C7—C6—C8—C6i | −160.50 (16) | C6i—C10—C11—F6i | 46.4 (4) |
Mo1—C6—C8—C6i | 69.50 (12) | C6—C10—C11—F6i | −168.3 (2) |
C10—C6—C8—C9 | 150.2 (3) | C8—C10—C11—F6i | 119.0 (2) |
C7—C6—C8—C9 | −9.2 (4) | Mo1—C10—C11—F6i | −61.0 (2) |
Mo1—C6—C8—C9 | −139.2 (3) | C6i—C10—C11—F7 | −72.6 (2) |
C7—C6—C8—C10 | −159.5 (3) | C6—C10—C11—F7 | 72.6 (2) |
Mo1—C6—C8—C10 | 70.54 (12) | C8—C10—C11—F7 | 0.000 (2) |
C10—C6—C8—Mo1 | −70.54 (12) | Mo1—C10—C11—F7 | 180.0 |
Symmetry code: (i) x, −y+1/2, z. |
Experimental details
Crystal data | |
Chemical formula | [Mo(C8F12)(C5H5)(C3H6NS2)] |
Mr | 605.32 |
Crystal system, space group | Monoclinic, P21/m |
Temperature (K) | 295 |
a, b, c (Å) | 8.918 (1), 12.185 (1), 9.809 (2) |
β (°) | 106.28 (1) |
V (Å3) | 1023.2 (3) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.96 |
Crystal size (mm) | 0.54 × 0.45 × 0.28 |
Data collection | |
Diffractometer | Enraf–Nonius CAD-4 diffractometer |
Absorption correction | Gaussian Shape of crystal defined by six pairs of parallel faces. |
Tmin, Tmax | 0.730, 0.800 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5153, 3025, 2761 |
Rint | 0.020 |
(sin θ/λ)max (Å−1) | 0.704 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.024, 0.069, 1.06 |
No. of reflections | 3025 |
No. of parameters | 162 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.40, −0.35 |
Computer programs: CAD-4 EXPRESS (Enraf–Nonius, 1984), CAD-4 EXPRESS, GX (Mallinson & Muir, 1985), GX, SHELXL97 (Sheldrick, 1997), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).
Mo1—C3 | 2.309 (3) | Mo1—S1 | 2.4697 (5) |
Mo1—C4 | 2.324 (2) | C6—C10 | 1.448 (2) |
Mo1—C5 | 2.324 (2) | C6—C8 | 1.461 (2) |
Mo1—C6 | 2.198 (2) | C6—C7 | 1.476 (3) |
Mo1—C8 | 2.189 (2) | C8—C9 | 1.480 (3) |
Mo1—C10 | 2.211 (2) | C10—C11 | 1.490 (4) |
C10—C6—C8 | 88.85 (13) | C6—C8—C6i | 90.61 (18) |
C10—C6—C8—C6i | −1.0 (2) |
Symmetry code: (i) x, −y+1/2, z. |
Acknowledgements
The authors thank the EPSRC and Glasgow and Heriot–Watt Universities for support.
References
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Complexes with η4-C4R4 cyclobutadienyl ligands are known for many transition metals. For example, nine structures containing the η4-C4R4–Mo moiety occur in the Cambridge Structural Database (CSD; Version 5.25 of November 2003; Allen, 2002) (structural searches were carried out locally using the QUEST and CONQUEST search programs). In most of these, R = Ph (CSD refcodes GICGUU10, LUJZOF, LUKBAU, LUJZUL, PABPMO, PCBMOC10 and TPCBMO), but an R = p-CH3C6H4 complex (GIQTIJ) and a C4Ph3Me species (COXVIU) have also been characterized (see supplementary data for a list of references). We now describe the structure of the title compound, CpCbMo(S2CNMe2), (I), where Cp = η5-C5H5, Cb = η4-C4R4 and R is the strongly electron-withdrawing CF3 group. Compound (I) is the first structural example of a η4-C4(CF3)4 complex of any transition metal.
Molecules of (1) have exact Cs symmetry; atoms Mo1, N1, C1, C3, C8–C11, F4 and F7 all lie on a crystallographic mirror plane in space group P21m, selected for the reference molecule as that at y = 1/4 (Fig. 1). The metal coordination is pseudo-tetrahedral, being defined by Cp—Mo—Cb and S—Mo—Si angles of 136.6 (2) and 70.0 (1)° (here Cp and Cb are the centroids of the C5 and C4 rings). The bonding in pseudo-tetrahedral CpCbMoL2 species such as (I) has been reviewed by Curnow et al. (1993), who argue that the Cb ligand is best considered as a dianionic C4R42− six-electron donor isoelectronic with Cp−, making (I) a d2 MoIV complex. The metal lone pair in such complexes occupies a stereochemically active dz2-like orbital, compressing the L—M—L angle. Thus, the Cl—Mo—Cl angle in Cp2MoCl2 (Prout et al., 1974) is 82°, only 12° less acute than the S—Mo—Si angle in (I).
The Mo—S distance in (I) (Table 1) differs by only 0.002 (1) Å from the comparable mean of 2.472 Å in the isoelectronic MoIV cation [(η5-In)2Mo(S2CNEt2]+ (In is indenyl; Drew et al., 1998). The Mo—C(Cp) bond lengths are also unexceptional and the displacement of Mo from the Cp plane [2.012 (1) Å] is close to the average of 2.008 (1) Å for all CpMo compounds in the CSD. However, variations in Cp ring C—C distances and angles [1.338 (9)–1.391 (4) Å and 105.9 (4)–109.2 (2)°], and Ueq values of Cp ring C atoms nearly three times that of the Mo atom, suggest substantial libration, possibly even some disorder, of the ring about the Mo—Cp vector.
The Cb ligand deviates only slightly from C4v symmetry. Thus, the ring C—C bond lengths differ by only 0.013 (4) Å. Atoms C7, C9 and C11 are displaced, by 0.340 (2), 0.562 (4) and 0.504 (3) Å, respectively, to the opposite side of the C4 ring plane from the Mo atom, probably to relieve intraligand repulsions. Rotation of the C7F3 group from its ideal position by ca 8° is shown by F1—C7—C6—C8 and F1—C7—C6—C10 torsion angles of 84.1 (3) and −67.6 (3)°. The near equality of the Ueq values for the Mo and the Cb ring C atoms is consistent with the high barrier to libration about the Mo—Cb vector suggested by spectroscopic evidence (Davidson, 1987).
In other (η4-C4R4)Mo complexes, the ring C—C bond lengths usually show little variation and their average value of 1.462 (2) Å agrees well with the individual values in (I). In contrast, the ring C—C bond lengths in C4R4 molecules indicate fixed double and single bonds (Irmgartinger et al., 1988, and references therein).
The Mo—C(Cb) bond lengths in (I) vary slightly and are on average 0.08 Å shorter than the mean value of 2.284 (7) Å for other (η4-C4R4)Mo complexes (where R = Me, Ph etc.). The displacement of the Mo atom from the Cb ring plane in (I) [1.944 (1) Å] is likewise less than the values of 1.995–2.074 Å found in other Mo—Cb complexes.
Curnow et al. (1993) substantiate their view of Cb as a C4R42− dianionic ligand from extended Hückel molecular-orbital (EHMO) calculations, which show that in CpCbMoL2 species much more charge is transferred from Mo to Cb than to Cp. Electron-withdrawing CF3 substituents on the Cb C atoms might be expected to facilitate this transfer and thus to produce the very strong Mo—Cb π-bonds found in (I).