Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807059491/sg2205sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807059491/sg2205Isup2.hkl |
CCDC reference: 672709
The sodium salt Na[1,3-(Me3C)2C5H3] (2.71 g, 0.0135 mol) and Cr2(OAc)4 (1.15 g, 3.39 mmol) were weighed into a Schlenk flask equipped with a magnetic stirrer under a flow of dinitrogen. THF (180 ml) was added and the slurry was stirred at room temperature for one hour, then heated to reflux and stirred at reflux overnight. The solvent was then removed under reduced pressure and the residue was extracted to pentane (100 ml). The volume of solvent was reduced and the solution was cooled to -80°C. Large red air-sensitive crystals formed in 77% yield. mp 183–184°C. 1H NMR (C6D6, 23°C): δ 0.2 (ν1/2 = 250 Hz, Me3C) (ring protons not observed). The molecule sublimes under dynamic vacuum. The synthesis of compound (I) has also been reported by a different route (Overby et al., 1998). For data collection, a red crystal was placed in Paratone N hydrocarbon oil and then mounted on a glass fiber.
Data collection: SMART (Siemens, 1995a); cell refinement: XPREP (Sheldrick, 1995); data reduction: SAINT (Siemens, 1995b); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997b); molecular graphics: XP in SHELXTL (Sheldrick, 1998); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997b).
[Cr(C13H21)2] | Dx = 1.133 Mg m−3 |
Mr = 406.60 | Melting point: not measured K |
Orthorhombic, Pccn | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ab 2ac | Cell parameters from 5151 reflections |
a = 11.7750 (6) Å | θ = 1.5–44.3° |
b = 12.4122 (6) Å | µ = 0.49 mm−1 |
c = 32.621 (2) Å | T = 134 K |
V = 4767.7 (4) Å3 | Block, red |
Z = 8 | 0.21 × 0.19 × 0.08 mm |
F(000) = 1776 |
Bruker SMART 1K CCD diffractometer | 4385 independent reflections |
Radiation source: fine-focus sealed tube | 2665 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.077 |
ω–scan | θmax = 26.3°, θmin = 1.3° |
Absorption correction: multi-scan (XPREP; Sheldrick, 1995) | h = −12→13 |
Tmin = 0.905, Tmax = 0.962 | k = −14→15 |
21800 measured reflections | l = −29→39 |
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)] = 0.044 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.114 | H-atom parameters constrained |
S = 1.02 | w = 1/[σ2(Fo2) + (0.0517P)2 + 1.131P] where P = (Fo2 + 2Fc2)/3 |
4385 reflections | (Δ/σ)max < 0.001 |
257 parameters | Δρmax = 0.29 e Å−3 |
0 restraints | Δρmin = −0.26 e Å−3 |
[Cr(C13H21)2] | V = 4767.7 (4) Å3 |
Mr = 406.60 | Z = 8 |
Orthorhombic, Pccn | Mo Kα radiation |
a = 11.7750 (6) Å | µ = 0.49 mm−1 |
b = 12.4122 (6) Å | T = 134 K |
c = 32.621 (2) Å | 0.21 × 0.19 × 0.08 mm |
Bruker SMART 1K CCD diffractometer | 4385 independent reflections |
Absorption correction: multi-scan (XPREP; Sheldrick, 1995) | 2665 reflections with I > 2σ(I) |
Tmin = 0.905, Tmax = 0.962 | Rint = 0.077 |
21800 measured reflections |
R[F2 > 2σ(F2)] = 0.044 | 0 restraints |
wR(F2) = 0.114 | H-atom parameters constrained |
S = 1.02 | Δρmax = 0.29 e Å−3 |
4385 reflections | Δρmin = −0.26 e Å−3 |
257 parameters |
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 | ||
Cr1 | 0.2500 | 0.7500 | 0.044372 (18) | 0.01940 (17) | |
Cr2 | 0.2500 | 0.2500 | 0.181375 (18) | 0.01916 (17) | |
C1 | 0.3177 (2) | 0.5946 (2) | 0.02512 (9) | 0.0212 (7) | |
C2 | 0.3437 (2) | 0.6067 (2) | 0.06750 (8) | 0.0207 (7) | |
H2 | 0.3188 | 0.5594 | 0.0886 | 0.025* | |
C3 | 0.4122 (2) | 0.6995 (2) | 0.07379 (8) | 0.0222 (7) | |
C4 | 0.4290 (2) | 0.7466 (2) | 0.03457 (8) | 0.0234 (6) | |
H4 | 0.4712 | 0.8102 | 0.0292 | 0.028* | |
C5 | 0.3721 (2) | 0.6824 (2) | 0.00459 (9) | 0.0220 (7) | |
H5 | 0.3706 | 0.6957 | −0.0241 | 0.026* | |
C6 | 0.2885 (2) | 0.4079 (2) | 0.21043 (9) | 0.0228 (7) | |
C7 | 0.3923 (2) | 0.3517 (2) | 0.20460 (9) | 0.0230 (7) | |
H7 | 0.4439 | 0.3332 | 0.2259 | 0.028* | |
C8 | 0.4079 (2) | 0.3272 (2) | 0.16259 (9) | 0.0213 (7) | |
C9 | 0.3112 (2) | 0.3702 (2) | 0.14162 (9) | 0.0221 (7) | |
H9 | 0.2981 | 0.3669 | 0.1129 | 0.026* | |
C10 | 0.2378 (3) | 0.4189 (2) | 0.17099 (9) | 0.0252 (7) | |
H10 | 0.1673 | 0.4528 | 0.1653 | 0.030* | |
C11 | 0.2585 (3) | 0.4994 (2) | 0.00510 (8) | 0.0239 (6) | |
C12 | 0.1652 (3) | 0.4525 (2) | 0.03243 (9) | 0.0309 (8) | |
H12A | 0.1978 | 0.4315 | 0.0589 | 0.046* | |
H12B | 0.1320 | 0.3892 | 0.0191 | 0.046* | |
H12C | 0.1061 | 0.5069 | 0.0368 | 0.046* | |
C13 | 0.3488 (3) | 0.4123 (2) | −0.00243 (11) | 0.0428 (9) | |
H13A | 0.4074 | 0.4406 | −0.0208 | 0.064* | |
H13B | 0.3131 | 0.3491 | −0.0150 | 0.064* | |
H13C | 0.3834 | 0.3916 | 0.0237 | 0.064* | |
C14 | 0.2046 (3) | 0.5316 (3) | −0.03600 (9) | 0.0365 (8) | |
H14A | 0.1471 | 0.5873 | −0.0313 | 0.055* | |
H14B | 0.1688 | 0.4684 | −0.0485 | 0.055* | |
H14C | 0.2635 | 0.5596 | −0.0544 | 0.055* | |
C61 | 0.2435 (3) | 0.4578 (2) | 0.25000 (9) | 0.0271 (7) | |
C62 | 0.2590 (3) | 0.5806 (2) | 0.24669 (10) | 0.0371 (8) | |
H62A | 0.3396 | 0.5972 | 0.2426 | 0.056* | |
H62B | 0.2322 | 0.6149 | 0.2720 | 0.056* | |
H62C | 0.2151 | 0.6078 | 0.2234 | 0.056* | |
C63 | 0.3097 (3) | 0.4167 (3) | 0.28684 (9) | 0.0359 (8) | |
H63A | 0.3036 | 0.3381 | 0.2883 | 0.054* | |
H63B | 0.2784 | 0.4485 | 0.3119 | 0.054* | |
H63C | 0.3897 | 0.4372 | 0.2841 | 0.054* | |
C64 | 0.1172 (3) | 0.4333 (3) | 0.25587 (10) | 0.0394 (9) | |
H64A | 0.0746 | 0.4592 | 0.2320 | 0.059* | |
H64B | 0.0897 | 0.4697 | 0.2806 | 0.059* | |
H64C | 0.1065 | 0.3554 | 0.2587 | 0.059* | |
C31 | 0.4666 (2) | 0.7361 (2) | 0.11388 (9) | 0.0256 (7) | |
C32 | 0.4532 (3) | 0.8584 (2) | 0.11985 (10) | 0.0368 (8) | |
H32A | 0.4852 | 0.8962 | 0.0961 | 0.055* | |
H32B | 0.4934 | 0.8806 | 0.1447 | 0.055* | |
H32C | 0.3724 | 0.8762 | 0.1225 | 0.055* | |
C33 | 0.4152 (3) | 0.6778 (3) | 0.15074 (9) | 0.0361 (8) | |
H33A | 0.3334 | 0.6919 | 0.1519 | 0.054* | |
H33B | 0.4511 | 0.7039 | 0.1760 | 0.054* | |
H33C | 0.4282 | 0.6001 | 0.1480 | 0.054* | |
C34 | 0.5942 (3) | 0.7094 (3) | 0.11186 (10) | 0.0371 (8) | |
H34A | 0.6040 | 0.6326 | 0.1059 | 0.056* | |
H34B | 0.6298 | 0.7266 | 0.1382 | 0.056* | |
H34C | 0.6299 | 0.7522 | 0.0901 | 0.056* | |
C81 | 0.5135 (2) | 0.2797 (2) | 0.14232 (9) | 0.0234 (7) | |
C82 | 0.5899 (3) | 0.3743 (3) | 0.12892 (10) | 0.0350 (8) | |
H82A | 0.6575 | 0.3461 | 0.1150 | 0.053* | |
H82B | 0.6130 | 0.4157 | 0.1531 | 0.053* | |
H82C | 0.5477 | 0.4211 | 0.1101 | 0.053* | |
C83 | 0.4825 (3) | 0.2132 (2) | 0.10470 (9) | 0.0340 (8) | |
H83A | 0.4345 | 0.1525 | 0.1130 | 0.051* | |
H83B | 0.5519 | 0.1859 | 0.0918 | 0.051* | |
H83C | 0.4411 | 0.2584 | 0.0851 | 0.051* | |
C84 | 0.5793 (2) | 0.2087 (3) | 0.17218 (9) | 0.0316 (8) | |
H84A | 0.5305 | 0.1497 | 0.1816 | 0.047* | |
H84B | 0.6035 | 0.2518 | 0.1958 | 0.047* | |
H84C | 0.6463 | 0.1789 | 0.1584 | 0.047* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cr1 | 0.0175 (3) | 0.0205 (3) | 0.0202 (4) | 0.0028 (3) | 0.000 | 0.000 |
Cr2 | 0.0189 (3) | 0.0191 (3) | 0.0195 (3) | −0.0008 (3) | 0.000 | 0.000 |
C1 | 0.0182 (16) | 0.0217 (15) | 0.0237 (17) | 0.0048 (13) | 0.0014 (13) | 0.0011 (13) |
C2 | 0.0205 (16) | 0.0207 (15) | 0.0208 (16) | 0.0032 (13) | 0.0000 (13) | 0.0015 (13) |
C3 | 0.0176 (15) | 0.0264 (16) | 0.0227 (17) | 0.0032 (13) | −0.0001 (13) | 0.0017 (14) |
C4 | 0.0186 (14) | 0.0208 (14) | 0.0308 (16) | 0.0001 (14) | 0.0038 (12) | −0.0007 (15) |
C5 | 0.0184 (15) | 0.0250 (16) | 0.0225 (17) | 0.0041 (13) | 0.0042 (13) | −0.0001 (13) |
C6 | 0.0226 (15) | 0.0218 (15) | 0.0241 (17) | −0.0014 (13) | 0.0007 (13) | 0.0006 (13) |
C7 | 0.0240 (16) | 0.0239 (15) | 0.0210 (17) | −0.0032 (13) | −0.0051 (13) | 0.0025 (13) |
C8 | 0.0215 (16) | 0.0200 (15) | 0.0225 (16) | −0.0054 (13) | −0.0012 (13) | 0.0012 (13) |
C9 | 0.0271 (17) | 0.0194 (15) | 0.0198 (17) | −0.0032 (13) | −0.0005 (13) | 0.0033 (13) |
C10 | 0.0241 (17) | 0.0192 (14) | 0.0322 (17) | 0.0015 (14) | −0.0014 (14) | 0.0025 (13) |
C11 | 0.0256 (16) | 0.0224 (14) | 0.0236 (15) | 0.0009 (14) | 0.0006 (15) | −0.0023 (12) |
C12 | 0.0351 (19) | 0.0294 (17) | 0.0281 (19) | −0.0065 (15) | −0.0056 (15) | 0.0023 (15) |
C13 | 0.039 (2) | 0.0292 (18) | 0.060 (2) | 0.0042 (16) | −0.0033 (18) | −0.0139 (18) |
C14 | 0.046 (2) | 0.038 (2) | 0.0246 (19) | −0.0098 (16) | −0.0054 (15) | −0.0028 (15) |
C31 | 0.0210 (15) | 0.0266 (17) | 0.0292 (17) | 0.0015 (14) | −0.0045 (13) | −0.0037 (14) |
C32 | 0.039 (2) | 0.0331 (19) | 0.039 (2) | 0.0012 (16) | −0.0122 (16) | −0.0095 (16) |
C33 | 0.040 (2) | 0.043 (2) | 0.0256 (19) | −0.0033 (16) | −0.0072 (16) | 0.0005 (16) |
C34 | 0.0281 (18) | 0.044 (2) | 0.039 (2) | 0.0013 (15) | −0.0122 (16) | −0.0042 (16) |
C61 | 0.0242 (16) | 0.0265 (16) | 0.0306 (17) | −0.0005 (16) | 0.0003 (16) | −0.0067 (13) |
C62 | 0.044 (2) | 0.0304 (17) | 0.0374 (19) | −0.0014 (18) | 0.0040 (17) | −0.0119 (15) |
C63 | 0.0387 (19) | 0.042 (2) | 0.0271 (19) | 0.0016 (17) | 0.0016 (16) | −0.0069 (16) |
C64 | 0.0309 (19) | 0.049 (2) | 0.038 (2) | −0.0016 (17) | 0.0084 (16) | −0.0178 (17) |
C81 | 0.0197 (15) | 0.0263 (17) | 0.0242 (17) | −0.0006 (12) | 0.0026 (13) | −0.0008 (13) |
C82 | 0.0292 (18) | 0.0374 (19) | 0.038 (2) | −0.0041 (15) | 0.0093 (16) | 0.0024 (16) |
C83 | 0.0324 (18) | 0.0415 (19) | 0.0280 (18) | 0.0009 (15) | 0.0050 (15) | −0.0053 (15) |
C84 | 0.0248 (17) | 0.0380 (18) | 0.0321 (19) | 0.0036 (15) | 0.0027 (15) | 0.0003 (15) |
Cr1—C1i | 2.180 (3) | C12—H12A | 0.9800 |
Cr1—C1 | 2.180 (3) | C12—H12B | 0.9800 |
Cr1—C2i | 2.225 (3) | C12—H12C | 0.9800 |
Cr1—C2 | 2.225 (3) | C13—H13A | 0.9800 |
Cr1—C3i | 2.228 (3) | C13—H13B | 0.9800 |
Cr1—C3 | 2.228 (3) | C13—H13C | 0.9800 |
Cr1—C4i | 2.133 (3) | C14—H14A | 0.9800 |
Cr1—C4 | 2.133 (3) | C14—H14B | 0.9800 |
Cr1—C5i | 2.111 (3) | C14—H14C | 0.9800 |
Cr1—C5 | 2.111 (3) | C61—C63 | 1.520 (4) |
Cr1—Cg1 | 1.807 | C61—C64 | 1.529 (4) |
Cr2—C6 | 2.224 (3) | C61—C62 | 1.539 (4) |
Cr2—C6ii | 2.224 (3) | C62—H62A | 0.9800 |
Cr2—C7 | 2.230 (3) | C62—H62B | 0.9800 |
Cr2—C7ii | 2.230 (3) | C62—H62C | 0.9800 |
Cr2—C8ii | 2.179 (3) | C63—H63A | 0.9800 |
Cr2—C8 | 2.179 (3) | C63—H63B | 0.9800 |
Cr2—C9ii | 2.104 (3) | C63—H63C | 0.9800 |
Cr2—C9 | 2.104 (3) | C64—H64A | 0.9800 |
Cr2—C10 | 2.128 (3) | C64—H64B | 0.9800 |
Cr2—C10ii | 2.128 (3) | C64—H64C | 0.9800 |
Cr2—Cg2 | 1.805 | C31—C33 | 1.529 (4) |
C1—C2 | 1.424 (4) | C31—C32 | 1.538 (4) |
C1—C5 | 1.430 (4) | C31—C34 | 1.540 (4) |
C1—C11 | 1.520 (4) | C32—H32A | 0.9800 |
C2—C3 | 1.422 (4) | C32—H32B | 0.9800 |
C2—H2 | 0.9500 | C32—H32C | 0.9800 |
C3—C4 | 1.420 (4) | C33—H33A | 0.9800 |
C3—C31 | 1.525 (4) | C33—H33B | 0.9800 |
C4—C5 | 1.429 (4) | C33—H33C | 0.9800 |
C4—H4 | 0.9500 | C34—H34A | 0.9800 |
C5—H5 | 0.9500 | C34—H34B | 0.9800 |
C6—C7 | 1.420 (4) | C34—H34C | 0.9800 |
C6—C10 | 1.425 (4) | C81—C83 | 1.524 (4) |
C6—C61 | 1.526 (4) | C81—C84 | 1.525 (4) |
C7—C8 | 1.416 (4) | C81—C82 | 1.541 (4) |
C7—H7 | 0.9500 | C82—H82A | 0.9800 |
C8—C9 | 1.432 (4) | C82—H82B | 0.9800 |
C8—C81 | 1.527 (4) | C82—H82C | 0.9800 |
C9—C10 | 1.424 (4) | C83—H83A | 0.9800 |
C9—H9 | 0.9500 | C83—H83B | 0.9800 |
C10—H10 | 0.9500 | C83—H83C | 0.9800 |
C11—C12 | 1.529 (4) | C84—H84A | 0.9800 |
C11—C14 | 1.536 (4) | C84—H84B | 0.9800 |
C11—C13 | 1.536 (4) | C84—H84C | 0.9800 |
Cg1i—Cr1—Cg1 | 173.3 | C10—C6—C61 | 125.4 (3) |
Cg2ii—Cr2—Cg2 | 173.1 | C7—C6—Cr2 | 71.66 (16) |
C5i—Cr1—C5 | 104.13 (16) | C10—C6—Cr2 | 67.29 (15) |
C5i—Cr1—C4i | 39.34 (10) | C61—C6—Cr2 | 130.32 (19) |
C5—Cr1—C4i | 126.08 (11) | C8—C7—C6 | 110.3 (2) |
C5i—Cr1—C4 | 126.08 (11) | C8—C7—Cr2 | 69.33 (15) |
C5—Cr1—C4 | 39.34 (10) | C6—C7—Cr2 | 71.16 (16) |
C4i—Cr1—C4 | 162.75 (15) | C8—C7—H7 | 124.8 |
C5i—Cr1—C1i | 38.89 (10) | C6—C7—H7 | 124.8 |
C5—Cr1—C1i | 115.10 (11) | Cr2—C7—H7 | 126.3 |
C4i—Cr1—C1i | 65.00 (11) | C7—C8—C9 | 106.2 (2) |
C4—Cr1—C1i | 109.65 (11) | C7—C8—C81 | 127.4 (2) |
C5i—Cr1—C1 | 115.09 (11) | C9—C8—C81 | 125.8 (3) |
C5—Cr1—C1 | 38.89 (10) | C7—C8—Cr2 | 73.23 (16) |
C4i—Cr1—C1 | 109.65 (11) | C9—C8—Cr2 | 67.67 (15) |
C4—Cr1—C1 | 65.00 (11) | C81—C8—Cr2 | 130.35 (19) |
C1i—Cr1—C1 | 146.51 (15) | C10—C9—C8 | 108.6 (3) |
C5i—Cr1—C2i | 63.43 (10) | C10—C9—Cr2 | 71.23 (15) |
C5—Cr1—C2i | 149.79 (10) | C8—C9—Cr2 | 73.33 (15) |
C4i—Cr1—C2i | 62.92 (11) | C10—C9—H9 | 125.7 |
C4—Cr1—C2i | 123.85 (11) | C8—C9—H9 | 125.7 |
C1i—Cr1—C2i | 37.70 (10) | Cr2—C9—H9 | 121.4 |
C1—Cr1—C2i | 170.62 (10) | C9—C10—C6 | 108.3 (3) |
C5i—Cr1—C2 | 149.79 (10) | C9—C10—Cr2 | 69.44 (15) |
C5—Cr1—C2 | 63.43 (10) | C6—C10—Cr2 | 74.57 (16) |
C4i—Cr1—C2 | 123.85 (11) | C9—C10—H10 | 125.9 |
C4—Cr1—C2 | 62.92 (11) | C6—C10—H10 | 125.9 |
C1i—Cr1—C2 | 170.62 (10) | Cr2—C10—H10 | 121.8 |
C1—Cr1—C2 | 37.70 (10) | C1—C11—C12 | 112.0 (2) |
C2i—Cr1—C2 | 140.35 (14) | C1—C11—C14 | 111.3 (2) |
C5i—Cr1—C3i | 64.46 (11) | C12—C11—C14 | 108.1 (2) |
C5—Cr1—C3i | 163.88 (11) | C1—C11—C13 | 107.3 (2) |
C4i—Cr1—C3i | 37.93 (10) | C12—C11—C13 | 108.8 (2) |
C4—Cr1—C3i | 156.62 (11) | C14—C11—C13 | 109.2 (3) |
C1i—Cr1—C3i | 63.98 (10) | C11—C12—H12A | 109.5 |
C1—Cr1—C3i | 133.38 (10) | C11—C12—H12B | 109.5 |
C2i—Cr1—C3i | 37.24 (10) | H12A—C12—H12B | 109.5 |
C2—Cr1—C3i | 120.26 (10) | C11—C12—H12C | 109.5 |
C5i—Cr1—C3 | 163.88 (11) | H12A—C12—H12C | 109.5 |
C5—Cr1—C3 | 64.46 (11) | H12B—C12—H12C | 109.5 |
C4i—Cr1—C3 | 156.62 (11) | C11—C13—H13A | 109.5 |
C4—Cr1—C3 | 37.93 (10) | C11—C13—H13B | 109.5 |
C1i—Cr1—C3 | 133.38 (10) | H13A—C13—H13B | 109.5 |
C1—Cr1—C3 | 63.98 (10) | C11—C13—H13C | 109.5 |
C2i—Cr1—C3 | 120.26 (10) | H13A—C13—H13C | 109.5 |
C2—Cr1—C3 | 37.24 (10) | H13B—C13—H13C | 109.5 |
C3i—Cr1—C3 | 128.98 (14) | C11—C14—H14A | 109.5 |
C9ii—Cr2—C9 | 103.90 (16) | C11—C14—H14B | 109.5 |
C9ii—Cr2—C10 | 125.26 (11) | H14A—C14—H14B | 109.5 |
C9—Cr2—C10 | 39.32 (11) | C11—C14—H14C | 109.5 |
C9ii—Cr2—C10ii | 39.32 (11) | H14A—C14—H14C | 109.5 |
C9—Cr2—C10ii | 125.26 (11) | H14B—C14—H14C | 109.5 |
C10—Cr2—C10ii | 161.68 (16) | C63—C61—C6 | 110.8 (2) |
C9ii—Cr2—C8ii | 39.01 (10) | C63—C61—C64 | 109.4 (3) |
C9—Cr2—C8ii | 115.49 (11) | C6—C61—C64 | 111.3 (2) |
C10—Cr2—C8ii | 109.31 (11) | C63—C61—C62 | 109.1 (2) |
C10ii—Cr2—C8ii | 65.15 (11) | C6—C61—C62 | 107.5 (2) |
C9ii—Cr2—C8 | 115.49 (11) | C64—C61—C62 | 108.7 (3) |
C9—Cr2—C8 | 39.01 (10) | C61—C62—H62A | 109.5 |
C10—Cr2—C8 | 65.15 (11) | C61—C62—H62B | 109.5 |
C10ii—Cr2—C8 | 109.31 (11) | H62A—C62—H62B | 109.5 |
C8ii—Cr2—C8 | 147.33 (15) | C61—C62—H62C | 109.5 |
C9ii—Cr2—C6 | 163.24 (11) | H62A—C62—H62C | 109.5 |
C9—Cr2—C6 | 64.40 (11) | H62B—C62—H62C | 109.5 |
C10—Cr2—C6 | 38.14 (10) | C61—C63—H63A | 109.5 |
C10ii—Cr2—C6 | 157.26 (11) | C61—C63—H63B | 109.5 |
C8ii—Cr2—C6 | 132.93 (10) | H63A—C63—H63B | 109.5 |
C8—Cr2—C6 | 63.81 (10) | C61—C63—H63C | 109.5 |
C9ii—Cr2—C6ii | 64.40 (11) | H63A—C63—H63C | 109.5 |
C9—Cr2—C6ii | 163.24 (11) | H63B—C63—H63C | 109.5 |
C10—Cr2—C6ii | 157.26 (11) | C61—C64—H64A | 109.5 |
C10ii—Cr2—C6ii | 38.14 (10) | C61—C64—H64B | 109.5 |
C8ii—Cr2—C6ii | 63.81 (10) | H64A—C64—H64B | 109.5 |
C8—Cr2—C6ii | 132.93 (10) | C61—C64—H64C | 109.5 |
C6—Cr2—C6ii | 129.54 (15) | H64A—C64—H64C | 109.5 |
C9ii—Cr2—C7 | 150.22 (11) | H64B—C64—H64C | 109.5 |
C9—Cr2—C7 | 63.31 (11) | C3—C31—C33 | 111.6 (2) |
C10—Cr2—C7 | 63.07 (11) | C3—C31—C32 | 111.1 (2) |
C10ii—Cr2—C7 | 124.13 (11) | C33—C31—C32 | 109.1 (2) |
C8ii—Cr2—C7 | 170.09 (10) | C3—C31—C34 | 108.0 (2) |
C8—Cr2—C7 | 37.44 (10) | C33—C31—C34 | 108.5 (2) |
C6—Cr2—C7 | 37.18 (10) | C32—C31—C34 | 108.5 (2) |
C6ii—Cr2—C7 | 120.48 (10) | C31—C32—H32A | 109.5 |
C9ii—Cr2—C7ii | 63.31 (11) | C31—C32—H32B | 109.5 |
C9—Cr2—C7ii | 150.22 (11) | H32A—C32—H32B | 109.5 |
C10—Cr2—C7ii | 124.13 (11) | C31—C32—H32C | 109.5 |
C10ii—Cr2—C7ii | 63.07 (11) | H32A—C32—H32C | 109.5 |
C8ii—Cr2—C7ii | 37.44 (10) | H32B—C32—H32C | 109.5 |
C8—Cr2—C7ii | 170.09 (10) | C31—C33—H33A | 109.5 |
C6—Cr2—C7ii | 120.48 (10) | C31—C33—H33B | 109.5 |
C6ii—Cr2—C7ii | 37.18 (10) | H33A—C33—H33B | 109.5 |
C7—Cr2—C7ii | 140.28 (15) | C31—C33—H33C | 109.5 |
C2—C1—C5 | 106.2 (2) | H33A—C33—H33C | 109.5 |
C2—C1—C11 | 126.7 (2) | H33B—C33—H33C | 109.5 |
C5—C1—C11 | 126.6 (3) | C31—C34—H34A | 109.5 |
C2—C1—Cr1 | 72.89 (15) | C31—C34—H34B | 109.5 |
C5—C1—Cr1 | 67.96 (15) | H34A—C34—H34B | 109.5 |
C11—C1—Cr1 | 130.08 (19) | C31—C34—H34C | 109.5 |
C3—C2—C1 | 110.3 (2) | H34A—C34—H34C | 109.5 |
C3—C2—Cr1 | 71.48 (16) | H34B—C34—H34C | 109.5 |
C1—C2—Cr1 | 69.41 (15) | C83—C81—C84 | 108.8 (2) |
C3—C2—H2 | 124.8 | C83—C81—C8 | 111.2 (2) |
C1—C2—H2 | 124.8 | C84—C81—C8 | 111.1 (2) |
Cr1—C2—H2 | 125.9 | C83—C81—C82 | 108.9 (2) |
C4—C3—C2 | 106.4 (2) | C84—C81—C82 | 109.0 (2) |
C4—C3—C31 | 126.3 (3) | C8—C81—C82 | 107.7 (2) |
C2—C3—C31 | 127.1 (3) | C81—C82—H82A | 109.5 |
C4—C3—Cr1 | 67.41 (15) | C81—C82—H82B | 109.5 |
C2—C3—Cr1 | 71.28 (15) | H82A—C82—H82B | 109.5 |
C31—C3—Cr1 | 130.19 (19) | C81—C82—H82C | 109.5 |
C3—C4—C5 | 108.8 (3) | H82A—C82—H82C | 109.5 |
C3—C4—Cr1 | 74.66 (16) | H82B—C82—H82C | 109.5 |
C5—C4—Cr1 | 69.49 (15) | C81—C83—H83A | 109.5 |
C3—C4—H4 | 125.6 | C81—C83—H83B | 109.5 |
C5—C4—H4 | 125.6 | H83A—C83—H83B | 109.5 |
Cr1—C4—H4 | 121.9 | C81—C83—H83C | 109.5 |
C4—C5—C1 | 108.3 (3) | H83A—C83—H83C | 109.5 |
C4—C5—Cr1 | 71.16 (15) | H83B—C83—H83C | 109.5 |
C1—C5—Cr1 | 73.16 (16) | C81—C84—H84A | 109.5 |
C4—C5—H5 | 125.8 | C81—C84—H84B | 109.5 |
C1—C5—H5 | 125.8 | H84A—C84—H84B | 109.5 |
Cr1—C5—H5 | 121.6 | C81—C84—H84C | 109.5 |
C7—C6—C10 | 106.6 (3) | H84A—C84—H84C | 109.5 |
C7—C6—C61 | 127.7 (3) | H84B—C84—H84C | 109.5 |
C1—C2—C3—C4 | 0.2 (3) | C7—C6—C61—C63 | −14.4 (4) |
C1—C2—C3—C31 | −174.6 (3) | C10—C6—C61—C63 | 172.3 (3) |
C2—C3—C4—C5 | −0.5 (3) | Cr2—C6—C61—C63 | 83.3 (3) |
C31—C3—C4—C5 | 174.3 (2) | C7—C6—C61—C64 | −136.4 (3) |
C3—C4—C5—C1 | 0.6 (3) | C10—C6—C61—C64 | 50.3 (4) |
C2—C1—C5—C4 | −0.5 (3) | C7—C6—C61—C62 | 104.7 (3) |
C6—C7—C8—C9 | 0.5 (3) | C10—C6—C61—C62 | −68.7 (4) |
C6—C7—C8—C81 | 172.1 (3) | C4—C3—C31—C33 | 171.3 (3) |
C7—C8—C9—C10 | −0.7 (3) | C2—C3—C31—C33 | −14.9 (4) |
C81—C8—C9—C10 | −172.6 (2) | C4—C3—C31—C32 | 49.4 (4) |
C8—C9—C10—C6 | 0.7 (3) | C2—C3—C31—C32 | −136.8 (3) |
C7—C6—C10—C9 | −0.4 (3) | C4—C3—C31—C34 | −69.5 (4) |
C61—C6—C10—C9 | 174.1 (2) | C2—C3—C31—C34 | 104.3 (3) |
C2—C1—C11—C12 | 36.7 (4) | C7—C8—C81—C83 | 150.6 (3) |
C5—C1—C11—C12 | −152.6 (3) | C9—C8—C81—C83 | −39.3 (4) |
C2—C1—C11—C14 | 157.9 (3) | C7—C8—C81—C84 | 29.2 (4) |
C5—C1—C11—C14 | −31.4 (4) | C9—C8—C81—C84 | −160.7 (3) |
C2—C1—C11—C13 | −82.7 (3) | C7—C8—C81—C82 | −90.1 (3) |
C5—C1—C11—C13 | 88.0 (3) | C9—C8—C81—C82 | 80.0 (3) |
Symmetry codes: (i) −x+1/2, −y+3/2, z; (ii) −x+1/2, −y+1/2, z. |
Experimental details
Crystal data | |
Chemical formula | [Cr(C13H21)2] |
Mr | 406.60 |
Crystal system, space group | Orthorhombic, Pccn |
Temperature (K) | 134 |
a, b, c (Å) | 11.7750 (6), 12.4122 (6), 32.621 (2) |
V (Å3) | 4767.7 (4) |
Z | 8 |
Radiation type | Mo Kα |
µ (mm−1) | 0.49 |
Crystal size (mm) | 0.21 × 0.19 × 0.08 |
Data collection | |
Diffractometer | Bruker SMART 1K CCD diffractometer |
Absorption correction | Multi-scan (XPREP; Sheldrick, 1995) |
Tmin, Tmax | 0.905, 0.962 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 21800, 4385, 2665 |
Rint | 0.077 |
(sin θ/λ)max (Å−1) | 0.623 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.044, 0.114, 1.02 |
No. of reflections | 4385 |
No. of parameters | 257 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.29, −0.26 |
Computer programs: SMART (Siemens, 1995a), XPREP (Sheldrick, 1995), SAINT (Siemens, 1995b), SHELXS97 (Sheldrick, 1997a), SHELXL97 (Sheldrick, 1997b), XP in SHELXTL (Sheldrick, 1998).
Cr1—C1 | 2.180 (3) | Cr2—C6 | 2.224 (3) |
Cr1—C2 | 2.225 (3) | Cr2—C7 | 2.230 (3) |
Cr1—C3 | 2.228 (3) | Cr2—C8 | 2.179 (3) |
Cr1—C4 | 2.133 (3) | Cr2—C9 | 2.104 (3) |
Cr1—C5 | 2.111 (3) | Cr2—C10 | 2.128 (3) |
Cr1—Cg1 | 1.807 | Cr2—Cg2 | 1.805 |
Cg1i—Cr1—Cg1 | 173.3 | Cg2ii—Cr2—Cg2 | 173.1 |
Symmetry codes: (i) −x+1/2, −y+3/2, z; (ii) −x+1/2, −y+1/2, z. |
The properties of metallocenes vary widely depending on the substituents on the cyclopentadienyl ring. The bulky ligand [1,3-(Me3C)2C5H3]- has been found to have electronic properties similar to (Me5C5)- in ytterbocenes (Schultz et al., 2001), but quite different steric properties leading to different solid state packing arrangements in the base-free metallocenes (Schultz et al., 2000). The chromocene of this ligand, the title compound (I), was prepared as part of a study of first row metallocenes with bulky substituents.
The compound (I) crystallizes with two half-molecules in the asymmetric unit and the metals lying on special positions. The compound is isostructural with the iron and cobalt analogues, which are the only other base-free transition metal metallocenes with this ligand that have been structurally characterized (Boese et al., 1993), (Schneider et al., 1997). Table 1 gives selected bond distances and angles for (I); Cg1 and Cg2 are the calculated centroids of the rings C1 - C5 and C6 - C10, respectively. Figure 1 is an ORTEP diagram showing the atom labelling scheme.
Compound (I) is the first example of a bent chromocene, with centroid - metal - centroid angle 173°. The metallocenes [1,3-(Me3C)2C5H3]2Fe and [1,3-(Me3C)2C5H3]2Co are also unusual examples of bent metallocenes of those metals. This is presumably due to the steric bulk of the four tertiary butyl groups, which force the rings to bend back although there are no close metal - carbon distances indicating agostic metal - hydrogen interactions.
The twist angle of a metallocene is defined as the mean value of the five angles between a ring carbon atom on the upper ring and the closest one on the lower ring. The angles are measured between the planes defined by the two centroids and each ring carbon atom. Thus, it can vary from zero (perfectly eclipsed), in which the rings lie directly above one another, to 36° (completely staggered), in which the plane containing the lower carbon atom bisects the 72° angle between two carbon atoms of the upper ring. The cyclopentadienyl rings of the two unique molecules in (I) are close to being eclipsed (twist angle molecule 1: 14.4°; molecule 2: 13.2°) and are oriented so that the tertiary butyl groups lie on alternating positions on each ring, presumably to minimize steric repulsions.
It is informative to compare the structural parameters for (I) with those of the five other base-free chromium(II) metallocenes that have been structurally characterized (excluding ansa-bridged examples). In the structures of unsubstituted (C5H5)2Cr (Flower & Hitchcock, 1996), (1,2,3,4-Ph4C5H)2Cr (Castellani et al., 1987) and [1,2,4-(Me2CH)3C5H2]2Cr (Overby et al., 1998), the chromium metal lies on a crystallographic inversion centre and the cyclopentadienyl rings are therefore exactly parallel and perfectly staggered (twist angles 36°). In (Me5C5)2Cr (Blümel et al., 1996) and (MeC5H4)2Cr (Benetollo et al., 1994), the centroid-metal-centroid angles are 179/180° (two unique molecules) and 178°, respectively, and the twist angles are 17/7° and 3°. Thus, (I) is the only significantly bent chromocene, although the twist angles in (I) are not unusual. The metal - ring centroid distances in all of these structures lie between 1.78 and 1.81 Å, except for (1,2,3,4-Ph4C5H)2Cr (1.832 Å), which shows elongated metal - ring distances due to the extreme bulk of the ligand in that case.