Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807030899/bt2409sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807030899/bt2409Isup2.hkl |
CCDC reference: 657529
The title compound was crystallized from THF/pentane by the reaction of ErCl3, 1,3 diisopropylimidazolin-2-ylidene and freshly prepared K2COT and by subsequent extraction and filtration from toluene. Elemental analysis: C27H37ErN2 (556.85 g/mol), Calculated: C 58.23, H 6.69, N 5.03; Found C 58.01, H 6.10, N 5.45%.
Methyl hydrogen atoms were located in a difference synthesis; the methyl groups were idealized and refined as rigid groups allowed to rotate but not tip, with C—H 0.98 Å, H—C—H 109.5°. Atom H17 was freely refined [C17—H17 refined to 0.91 (2) Å]. Other hydrogen atoms were included using a riding model with C—H 0.95 (aromatic), 1.00 (methylidyne) Å; U(H) values were fixed at 1.2U(C) of the parent C atom.
The two difference peaks larger than 1 e Å-3 are not located near the Er atom, but instead lie 1.12 Å from H1 and 1.89 Å from H27A, respectively. Since the largest peak has x and z coordinates equal to those of Er, we tentatively ascribe these peaks to the effect of a small unidentified twinning component.
In the supplementary material, the extremely long list of torsion angles involving the Er atom has been omitted.
After the synthesis of uranocene [(COT)2U] (COT = cyclooctatetraenyl, (C8H8)2-) by Streitwieser & Müller-Westerhoff (1968), bis-cyclooctatetraene complexes of divalent lanthanides were reported by Hayes & Thomas (1969). Streitwieser isolated trivalent lanthanide complexes of the type [K(COT)2Ln] (Ln = Y, La, Ce, Pr, Nd, Sm, Gd, Tb) (Mares et al., 1970; Streitwieser et al., 1973; Hodgson et al., 1973) using the same methodology as for the preparation of uranocene. Later, [K(COT)2Ln] complexes of ytterbium (Boussie et al., 1991) and lutetium (Schumann et al., 1993) were reported. In 1991 Chen synthesized an erbium complex with a tetralayer sandwich structure in which the adjacent Er3+ and K+ ions are bridged by η8-cyclooctatetraenyl groups (Xia et al., 1991). Here we report the anionic mononuclear sandwich complex of bis(cyclooctatetraenyl)erbium(III) with the carbenium cation 1,3- diisopropylimidazolium (Fig. 1).
The compound crystallizes without imposed symmetry. The coordination polyhedron is formed by two planar eight-membered rings (r.m.s. deviation 0.016, 0.006 Å) in an almost parallel arrangement with an interplanar angle of 2.21 (9)°. The perpendicular distances of the Er atom from the C8 planes are 1.8809 (7) and 1.8476 (8) Å. The angle cent1—Er—cent2 (cent = centroid) is 178°. The rings are eclipsed, as shown by torsion angles, e.g. C1—Cg1—Cg2—C12 = -3°, where Cg are ring centres of gravity. The individual Er—C bond lengths range from 2.596 (2)–2.651 (2) Å, which is comparable with Er—C(η8) [2.569 (14)–2.660 (19) Å], Er—C(η5) [2.629 (15)–2.654 (13) Å] reported for (COT)Er(µ-COT)K(µ-COT)Er(µ-COT)K(THF)4 (Xia et al. 1991), and (µ5-C5H5)2Er(µ-CH3)2Li(tmeda) (tmeda = tetramethylethylenediamine) (Schumann et al. 1985) respectively. In the imidazolium ion, the N—C distances [1.330 (3) and 1.335 (2) Å] are slightly shorter than those of 1,3-di(1-adamantyl)imidazol-2-ylidene reported by Arduengo et al. (1991) [1.367 (2) and 1.373 (2) Å], indicating delocalization of the positive charge over the N1—C17—N2 unit.
The packing involves several short interionic ("charge-assisted") contacts, principally from the more acidic H atoms H17, H20 and H25 (but also from H22C). The C—H bond distances were normalized to 1.08Å to calculate the contact distances. The shortest is from H25 to the centroid of C1–8, with H···cent 2.27 Å, C—H···cent 178°. The other contacts are best described as involving individual bonds as acceptors: C17—H17···C4,C5 [H···C 2.55, 2.31 Å, angles 156, 165°]; C20—H20···C10,C11 [2.73, 2.62 Å, 143, 133°, operator 1/2 + x, 1/2 - y, 1/2 + z]; C22—H22C—C12,C13 [2.80, 2.73 Å, 138, 163°, same operator]. The net effect is to connect the residues to form a chain parallel to (101) (Fig. 2). Between chains, a short C22···C22 contact is observed [3.168 (4) Å, operator 1 - x,1 - y,1 - z].
For related literature, see: Arduengo et al. (1991); Boussie et al. (1991); Hayes & Thomas (1969); Hodgson et al. (1973); Schumann et al. (1985, 1993); Streitwieser & Müller-Westerhoff (1968); Xia et al. (1991).
Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1998); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP (Siemens, 1994); software used to prepare material for publication: SHELXL97.
(C11H21N2)[Er(C8H8)2] | F(000) = 1124 |
Mr = 556.85 | Dx = 1.542 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
a = 12.7879 (12) Å | Cell parameters from 7131 reflections |
b = 8.7333 (8) Å | θ = 2–30° |
c = 21.531 (2) Å | µ = 3.51 mm−1 |
β = 94.100 (3)° | T = 133 K |
V = 2398.5 (4) Å3 | Tablet, yellow |
Z = 4 | 0.33 × 0.25 × 0.14 mm |
Bruker SMART 1000 CCD diffractometer | 7325 independent reflections |
Radiation source: fine-focus sealed tube | 6213 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.031 |
Detector resolution: 8.192 pixels mm-1 | θmax = 30.5°, θmin = 1.8° |
ω and φ scans | h = −18→18 |
Absorption correction: multi-scan (SADABS; Bruker, 1998) | k = −12→12 |
Tmin = 0.390, Tmax = 0.639 | l = −30→30 |
46432 measured reflections |
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)] = 0.020 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.042 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.11 | w = 1/[σ2(Fo2) + (0.0093P)2 + 2.7708P] where P = (Fo2 + 2Fc2)/3 |
7325 reflections | (Δ/σ)max = 0.002 |
281 parameters | Δρmax = 1.24 e Å−3 |
0 restraints | Δρmin = −0.88 e Å−3 |
(C11H21N2)[Er(C8H8)2] | V = 2398.5 (4) Å3 |
Mr = 556.85 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 12.7879 (12) Å | µ = 3.51 mm−1 |
b = 8.7333 (8) Å | T = 133 K |
c = 21.531 (2) Å | 0.33 × 0.25 × 0.14 mm |
β = 94.100 (3)° |
Bruker SMART 1000 CCD diffractometer | 7325 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 1998) | 6213 reflections with I > 2σ(I) |
Tmin = 0.390, Tmax = 0.639 | Rint = 0.031 |
46432 measured reflections |
R[F2 > 2σ(F2)] = 0.020 | 0 restraints |
wR(F2) = 0.042 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.11 | Δρmax = 1.24 e Å−3 |
7325 reflections | Δρmin = −0.88 e Å−3 |
281 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 | ||
Er | 0.294863 (6) | 0.393357 (10) | 0.098885 (4) | 0.01441 (3) | |
N1 | 0.59507 (12) | 0.71121 (19) | 0.27630 (7) | 0.0149 (3) | |
N2 | 0.62422 (13) | 0.5389 (2) | 0.34830 (7) | 0.0163 (3) | |
C1 | 0.36080 (18) | 0.6787 (3) | 0.09668 (10) | 0.0250 (4) | |
H1 | 0.3470 | 0.7621 | 0.0690 | 0.030* | |
C2 | 0.29094 (17) | 0.6728 (3) | 0.14489 (10) | 0.0244 (4) | |
H2 | 0.2409 | 0.7533 | 0.1420 | 0.029* | |
C3 | 0.27823 (17) | 0.5760 (3) | 0.19602 (10) | 0.0237 (4) | |
H3 | 0.2237 | 0.6094 | 0.2205 | 0.028* | |
C4 | 0.32684 (17) | 0.4418 (3) | 0.21950 (9) | 0.0228 (4) | |
H4 | 0.2963 | 0.4046 | 0.2555 | 0.027* | |
C5 | 0.41019 (17) | 0.3494 (3) | 0.20220 (9) | 0.0223 (4) | |
H5 | 0.4204 | 0.2616 | 0.2279 | 0.027* | |
C6 | 0.48199 (16) | 0.3570 (3) | 0.15561 (10) | 0.0237 (4) | |
H6 | 0.5318 | 0.2761 | 0.1586 | 0.028* | |
C7 | 0.49692 (16) | 0.4567 (3) | 0.10561 (10) | 0.0244 (4) | |
H7 | 0.5553 | 0.4284 | 0.0832 | 0.029* | |
C8 | 0.44589 (17) | 0.5887 (3) | 0.08083 (9) | 0.0249 (5) | |
H8 | 0.4764 | 0.6256 | 0.0448 | 0.030* | |
C9 | 0.30900 (18) | 0.1185 (3) | 0.05205 (12) | 0.0314 (5) | |
H9 | 0.3603 | 0.0396 | 0.0535 | 0.038* | |
C10 | 0.31984 (18) | 0.2205 (3) | 0.00278 (11) | 0.0318 (6) | |
H10 | 0.3780 | 0.1962 | −0.0205 | 0.038* | |
C11 | 0.2650 (2) | 0.3504 (3) | −0.02038 (10) | 0.0315 (6) | |
H11 | 0.2944 | 0.3931 | −0.0558 | 0.038* | |
C12 | 0.1758 (2) | 0.4324 (3) | −0.00302 (11) | 0.0329 (6) | |
H12 | 0.1585 | 0.5166 | −0.0297 | 0.040* | |
C13 | 0.10714 (18) | 0.4170 (3) | 0.04490 (12) | 0.0330 (6) | |
H13 | 0.0544 | 0.4938 | 0.0431 | 0.040* | |
C14 | 0.09810 (17) | 0.3154 (3) | 0.09458 (11) | 0.0326 (6) | |
H14 | 0.0405 | 0.3393 | 0.1184 | 0.039* | |
C15 | 0.15398 (19) | 0.1868 (3) | 0.11750 (10) | 0.0314 (5) | |
H15 | 0.1263 | 0.1457 | 0.1537 | 0.038* | |
C16 | 0.2406 (2) | 0.1052 (3) | 0.09965 (11) | 0.0321 (5) | |
H16 | 0.2571 | 0.0202 | 0.1261 | 0.038* | |
C17 | 0.56693 (15) | 0.5738 (2) | 0.29595 (9) | 0.0163 (4) | |
H17 | 0.5164 (17) | 0.515 (3) | 0.2758 (10) | 0.015 (6)* | |
C18 | 0.69194 (15) | 0.6603 (2) | 0.36310 (9) | 0.0184 (4) | |
C19 | 0.67409 (15) | 0.7684 (2) | 0.31794 (9) | 0.0183 (4) | |
C20 | 0.61502 (16) | 0.3970 (2) | 0.38588 (9) | 0.0193 (4) | |
H20 | 0.6873 | 0.3609 | 0.3994 | 0.023* | |
C21 | 0.5605 (2) | 0.2722 (3) | 0.34720 (11) | 0.0332 (6) | |
H21A | 0.5639 | 0.1759 | 0.3706 | 0.040* | |
H21B | 0.5951 | 0.2593 | 0.3084 | 0.040* | |
H21C | 0.4869 | 0.3005 | 0.3375 | 0.040* | |
C22 | 0.55787 (19) | 0.4316 (3) | 0.44359 (10) | 0.0284 (5) | |
H22A | 0.4867 | 0.4670 | 0.4312 | 0.034* | |
H22B | 0.5956 | 0.5116 | 0.4680 | 0.034* | |
H22C | 0.5544 | 0.3386 | 0.4688 | 0.034* | |
C23 | 0.76721 (18) | 0.6623 (3) | 0.41938 (10) | 0.0271 (5) | |
H23A | 0.8244 | 0.7338 | 0.4127 | 0.033* | |
H23B | 0.7959 | 0.5594 | 0.4268 | 0.033* | |
H23C | 0.7307 | 0.6952 | 0.4556 | 0.033* | |
C24 | 0.72744 (18) | 0.9190 (3) | 0.31202 (11) | 0.0277 (5) | |
H24A | 0.7691 | 0.9422 | 0.3509 | 0.033* | |
H24B | 0.6747 | 0.9992 | 0.3037 | 0.033* | |
H24C | 0.7736 | 0.9145 | 0.2776 | 0.033* | |
C25 | 0.54317 (15) | 0.7822 (2) | 0.21896 (8) | 0.0172 (4) | |
H25 | 0.4951 | 0.7030 | 0.1992 | 0.021* | |
C26 | 0.47505 (18) | 0.9167 (3) | 0.23510 (10) | 0.0266 (5) | |
H26A | 0.4251 | 0.8836 | 0.2649 | 0.032* | |
H26B | 0.4366 | 0.9547 | 0.1972 | 0.032* | |
H26C | 0.5194 | 0.9986 | 0.2537 | 0.032* | |
C27 | 0.62160 (18) | 0.8210 (3) | 0.17196 (10) | 0.0269 (5) | |
H27A | 0.6652 | 0.9072 | 0.1874 | 0.032* | |
H27B | 0.5842 | 0.8491 | 0.1323 | 0.032* | |
H27C | 0.6663 | 0.7319 | 0.1658 | 0.032* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Er | 0.01515 (4) | 0.01363 (4) | 0.01403 (4) | −0.00244 (3) | −0.00180 (3) | −0.00117 (3) |
N1 | 0.0138 (7) | 0.0175 (9) | 0.0131 (7) | 0.0002 (6) | −0.0003 (6) | −0.0001 (6) |
N2 | 0.0180 (8) | 0.0165 (9) | 0.0144 (7) | 0.0017 (6) | 0.0010 (6) | 0.0011 (6) |
C1 | 0.0349 (12) | 0.0153 (11) | 0.0233 (10) | −0.0087 (9) | −0.0080 (8) | 0.0038 (8) |
C2 | 0.0253 (10) | 0.0131 (10) | 0.0338 (11) | 0.0011 (8) | −0.0051 (8) | −0.0051 (9) |
C3 | 0.0225 (10) | 0.0231 (12) | 0.0261 (10) | −0.0023 (8) | 0.0050 (8) | −0.0114 (8) |
C4 | 0.0283 (11) | 0.0260 (11) | 0.0140 (9) | −0.0095 (8) | 0.0015 (8) | −0.0027 (8) |
C5 | 0.0267 (10) | 0.0204 (11) | 0.0185 (9) | −0.0046 (8) | −0.0074 (8) | 0.0030 (7) |
C6 | 0.0178 (9) | 0.0241 (12) | 0.0281 (11) | 0.0021 (7) | −0.0065 (8) | −0.0041 (8) |
C7 | 0.0169 (9) | 0.0325 (13) | 0.0241 (10) | −0.0056 (8) | 0.0029 (8) | −0.0085 (9) |
C8 | 0.0270 (10) | 0.0315 (13) | 0.0161 (9) | −0.0143 (9) | 0.0019 (8) | −0.0009 (8) |
C9 | 0.0290 (11) | 0.0196 (12) | 0.0436 (13) | 0.0023 (9) | −0.0105 (10) | −0.0143 (10) |
C10 | 0.0243 (11) | 0.0421 (15) | 0.0294 (12) | −0.0097 (10) | 0.0048 (9) | −0.0209 (10) |
C11 | 0.0416 (13) | 0.0385 (15) | 0.0141 (9) | −0.0209 (11) | 0.0003 (9) | −0.0033 (9) |
C12 | 0.0449 (14) | 0.0247 (13) | 0.0259 (11) | −0.0077 (10) | −0.0206 (10) | 0.0057 (9) |
C13 | 0.0233 (11) | 0.0341 (15) | 0.0390 (13) | 0.0075 (9) | −0.0171 (9) | −0.0121 (10) |
C14 | 0.0173 (10) | 0.0508 (16) | 0.0299 (12) | −0.0090 (10) | 0.0026 (8) | −0.0164 (11) |
C15 | 0.0319 (12) | 0.0390 (15) | 0.0230 (10) | −0.0221 (11) | −0.0002 (9) | 0.0021 (10) |
C16 | 0.0418 (13) | 0.0190 (11) | 0.0328 (12) | −0.0137 (10) | −0.0150 (10) | 0.0057 (10) |
C17 | 0.0163 (9) | 0.0172 (10) | 0.0153 (8) | 0.0006 (7) | 0.0011 (7) | −0.0003 (7) |
C18 | 0.0178 (9) | 0.0189 (10) | 0.0179 (9) | 0.0021 (7) | −0.0019 (7) | −0.0016 (7) |
C19 | 0.0161 (9) | 0.0192 (10) | 0.0192 (9) | −0.0006 (7) | −0.0024 (7) | −0.0025 (7) |
C20 | 0.0225 (9) | 0.0177 (10) | 0.0175 (8) | 0.0032 (8) | −0.0002 (7) | 0.0056 (8) |
C21 | 0.0511 (15) | 0.0224 (13) | 0.0252 (11) | −0.0061 (10) | −0.0046 (10) | 0.0058 (9) |
C22 | 0.0321 (12) | 0.0323 (14) | 0.0217 (10) | 0.0089 (9) | 0.0088 (9) | 0.0071 (9) |
C23 | 0.0295 (11) | 0.0265 (12) | 0.0234 (10) | −0.0016 (9) | −0.0114 (8) | −0.0001 (9) |
C24 | 0.0272 (11) | 0.0239 (13) | 0.0303 (11) | −0.0079 (9) | −0.0092 (9) | 0.0027 (9) |
C25 | 0.0189 (9) | 0.0192 (10) | 0.0129 (8) | −0.0014 (7) | −0.0029 (7) | 0.0010 (7) |
C26 | 0.0272 (11) | 0.0268 (13) | 0.0250 (10) | 0.0090 (9) | −0.0041 (8) | 0.0005 (9) |
C27 | 0.0308 (11) | 0.0316 (13) | 0.0186 (10) | −0.0040 (10) | 0.0043 (8) | 0.0035 (9) |
Er—C11 | 2.596 (2) | C10—C11 | 1.407 (4) |
Er—C13 | 2.599 (2) | C10—H10 | 0.9500 |
Er—C10 | 2.600 (2) | C11—C12 | 1.419 (4) |
Er—C15 | 2.600 (2) | C11—H11 | 0.9500 |
Er—C14 | 2.602 (2) | C12—C13 | 1.408 (4) |
Er—C12 | 2.602 (2) | C12—H12 | 0.9500 |
Er—C5 | 2.6080 (19) | C13—C14 | 1.401 (4) |
Er—C16 | 2.611 (2) | C13—H13 | 0.9500 |
Er—C9 | 2.615 (2) | C14—C15 | 1.402 (4) |
Er—C8 | 2.627 (2) | C14—H14 | 0.9500 |
Er—C6 | 2.627 (2) | C15—C16 | 1.395 (4) |
Er—C1 | 2.633 (2) | C15—H15 | 0.9500 |
Er—C4 | 2.634 (2) | C16—H16 | 0.9500 |
Er—C2 | 2.636 (2) | C17—H17 | 0.91 (2) |
Er—C7 | 2.636 (2) | C18—C19 | 1.363 (3) |
Er—C3 | 2.651 (2) | C18—C23 | 1.493 (3) |
N1—C17 | 1.330 (3) | C19—C24 | 1.491 (3) |
N1—C19 | 1.395 (2) | C20—C21 | 1.512 (3) |
N1—C25 | 1.494 (2) | C20—C22 | 1.516 (3) |
N2—C17 | 1.335 (2) | C20—H20 | 1.0000 |
N2—C18 | 1.391 (3) | C21—H21A | 0.9800 |
N2—C20 | 1.489 (3) | C21—H21B | 0.9800 |
C1—C8 | 1.404 (3) | C21—H21C | 0.9800 |
C1—C2 | 1.418 (3) | C22—H22A | 0.9800 |
C1—H1 | 0.9500 | C22—H22B | 0.9800 |
C2—C3 | 1.407 (3) | C22—H22C | 0.9800 |
C2—H2 | 0.9500 | C23—H23A | 0.9800 |
C3—C4 | 1.404 (3) | C23—H23B | 0.9800 |
C3—H3 | 0.9500 | C23—H23C | 0.9800 |
C4—C5 | 1.408 (3) | C24—H24A | 0.9800 |
C4—H4 | 0.9500 | C24—H24B | 0.9800 |
C5—C6 | 1.409 (3) | C24—H24C | 0.9800 |
C5—H5 | 0.9500 | C25—C27 | 1.513 (3) |
C6—C7 | 1.409 (3) | C25—C26 | 1.517 (3) |
C6—H6 | 0.9500 | C25—H25 | 1.0000 |
C7—C8 | 1.411 (3) | C26—H26A | 0.9800 |
C7—H7 | 0.9500 | C26—H26B | 0.9800 |
C8—H8 | 0.9500 | C26—H26C | 0.9800 |
C9—C16 | 1.399 (4) | C27—H27A | 0.9800 |
C9—C10 | 1.399 (4) | C27—H27B | 0.9800 |
C9—H9 | 0.9500 | C27—H27C | 0.9800 |
C11—Er—C13 | 60.21 (8) | C2—C3—Er | 73.97 (12) |
C11—Er—C10 | 31.42 (8) | C4—C3—H3 | 112.4 |
C13—Er—C10 | 81.51 (8) | C2—C3—H3 | 112.4 |
C11—Er—C15 | 89.87 (7) | Er—C3—H3 | 136.6 |
C13—Er—C15 | 59.75 (8) | C3—C4—C5 | 135.0 (2) |
C10—Er—C15 | 81.13 (8) | C3—C4—Er | 75.25 (12) |
C11—Er—C14 | 81.57 (7) | C5—C4—Er | 73.40 (11) |
C13—Er—C14 | 31.25 (8) | C3—C4—H4 | 112.5 |
C10—Er—C14 | 89.61 (7) | C5—C4—H4 | 112.5 |
C15—Er—C14 | 31.26 (9) | Er—C4—H4 | 134.9 |
C11—Er—C12 | 31.69 (9) | C4—C5—C6 | 134.9 (2) |
C13—Er—C12 | 31.40 (8) | C4—C5—Er | 75.45 (11) |
C10—Er—C12 | 60.18 (8) | C6—C5—Er | 75.13 (11) |
C15—Er—C12 | 81.41 (8) | C4—C5—H5 | 112.6 |
C14—Er—C12 | 59.87 (8) | C6—C5—H5 | 112.6 |
C11—Er—C5 | 148.95 (8) | Er—C5—H5 | 131.5 |
C13—Er—C5 | 147.24 (8) | C7—C6—C5 | 134.7 (2) |
C10—Er—C5 | 119.96 (8) | C7—C6—Er | 74.84 (12) |
C15—Er—C5 | 97.02 (7) | C5—C6—Er | 73.64 (11) |
C14—Er—C5 | 118.58 (7) | C7—C6—H6 | 112.6 |
C12—Er—C5 | 178.40 (7) | C5—C6—H6 | 112.6 |
C11—Er—C16 | 81.18 (8) | Er—C6—H6 | 134.9 |
C13—Er—C16 | 80.92 (8) | C6—C7—C8 | 135.3 (2) |
C10—Er—C16 | 59.54 (8) | C6—C7—Er | 74.11 (12) |
C15—Er—C16 | 31.04 (8) | C8—C7—Er | 74.08 (12) |
C14—Er—C16 | 59.42 (9) | C6—C7—H7 | 112.4 |
C12—Er—C16 | 89.53 (7) | C8—C7—H7 | 112.4 |
C5—Er—C16 | 89.27 (7) | Er—C7—H7 | 136.1 |
C11—Er—C9 | 59.69 (8) | C1—C8—C7 | 135.3 (2) |
C13—Er—C9 | 89.29 (7) | C1—C8—Er | 74.75 (12) |
C10—Er—C9 | 31.13 (8) | C7—C8—Er | 74.83 (12) |
C15—Er—C9 | 59.37 (8) | C1—C8—H8 | 112.3 |
C14—Er—C9 | 80.76 (8) | C7—C8—H8 | 112.3 |
C12—Er—C9 | 81.23 (8) | Er—C8—H8 | 133.7 |
C5—Er—C9 | 98.25 (7) | C16—C9—C10 | 135.2 (2) |
C16—Er—C9 | 31.06 (8) | C16—C9—Er | 74.33 (14) |
C11—Er—C8 | 90.30 (7) | C10—C9—Er | 73.84 (14) |
C13—Er—C8 | 123.19 (8) | C16—C9—H9 | 112.4 |
C10—Er—C8 | 97.24 (7) | C10—C9—H9 | 112.4 |
C15—Er—C8 | 176.50 (8) | Er—C9—H9 | 136.0 |
C14—Er—C8 | 152.13 (8) | C9—C10—C11 | 135.1 (2) |
C12—Er—C8 | 100.51 (7) | C9—C10—Er | 75.03 (13) |
C5—Er—C8 | 81.08 (7) | C11—C10—Er | 74.16 (13) |
C16—Er—C8 | 145.65 (8) | C9—C10—H10 | 112.5 |
C9—Er—C8 | 117.87 (8) | C11—C10—H10 | 112.5 |
C11—Er—C6 | 120.48 (8) | Er—C10—H10 | 134.1 |
C13—Er—C6 | 177.29 (8) | C10—C11—C12 | 134.7 (2) |
C10—Er—C6 | 98.05 (7) | C10—C11—Er | 74.43 (12) |
C15—Er—C6 | 117.55 (8) | C12—C11—Er | 74.38 (12) |
C14—Er—C6 | 146.24 (8) | C10—C11—H11 | 112.6 |
C12—Er—C6 | 150.07 (8) | C12—C11—H11 | 112.6 |
C5—Er—C6 | 31.23 (7) | Er—C11—H11 | 134.3 |
C16—Er—C6 | 96.55 (7) | C13—C12—C11 | 134.4 (2) |
C9—Er—C6 | 88.99 (7) | C13—C12—Er | 74.19 (12) |
C8—Er—C6 | 59.50 (7) | C11—C12—Er | 73.93 (12) |
C11—Er—C1 | 98.26 (7) | C13—C12—H12 | 112.8 |
C13—Er—C1 | 101.73 (8) | C11—C12—H12 | 112.8 |
C10—Er—C1 | 118.54 (8) | Er—C12—H12 | 135.2 |
C15—Er—C1 | 152.33 (8) | C14—C13—C12 | 135.2 (2) |
C14—Er—C1 | 123.86 (8) | C14—C13—Er | 74.47 (12) |
C12—Er—C1 | 91.70 (7) | C12—C13—Er | 74.40 (13) |
C5—Er—C1 | 89.56 (6) | C14—C13—H13 | 112.4 |
C16—Er—C1 | 176.61 (8) | C12—C13—H13 | 112.4 |
C9—Er—C1 | 146.21 (8) | Er—C13—H13 | 134.8 |
C8—Er—C1 | 30.97 (7) | C13—C14—C15 | 135.1 (2) |
C6—Er—C1 | 80.83 (7) | C13—C14—Er | 74.28 (13) |
C11—Er—C4 | 178.95 (7) | C15—C14—Er | 74.31 (12) |
C13—Er—C4 | 120.09 (8) | C13—C14—H14 | 112.4 |
C10—Er—C4 | 149.18 (8) | C15—C14—H14 | 112.4 |
C15—Er—C4 | 91.13 (7) | Er—C14—H14 | 135.1 |
C14—Er—C4 | 99.13 (7) | C16—C15—C14 | 135.1 (2) |
C12—Er—C4 | 148.26 (8) | C16—C15—Er | 74.91 (13) |
C5—Er—C4 | 31.15 (7) | C14—C15—Er | 74.43 (13) |
C16—Er—C4 | 99.85 (7) | C16—C15—H15 | 112.5 |
C9—Er—C4 | 121.16 (8) | C14—C15—H15 | 112.5 |
C8—Er—C4 | 88.72 (6) | Er—C15—H15 | 133.8 |
C6—Er—C4 | 59.27 (7) | C15—C16—C9 | 135.2 (2) |
C1—Er—C4 | 80.70 (7) | C15—C16—Er | 74.05 (14) |
C11—Er—C2 | 120.00 (8) | C9—C16—Er | 74.61 (14) |
C13—Er—C2 | 93.02 (7) | C15—C16—H16 | 112.4 |
C10—Er—C2 | 147.53 (8) | C9—C16—H16 | 112.4 |
C15—Er—C2 | 123.52 (8) | Er—C16—H16 | 135.1 |
C14—Er—C2 | 102.20 (8) | N1—C17—N2 | 109.26 (17) |
C12—Er—C2 | 99.78 (7) | N1—C17—H17 | 124.0 (14) |
C5—Er—C2 | 80.82 (7) | N2—C17—H17 | 126.8 (14) |
C16—Er—C2 | 151.40 (8) | C19—C18—N2 | 107.14 (16) |
C9—Er—C2 | 177.00 (7) | C19—C18—C23 | 129.5 (2) |
C8—Er—C2 | 59.21 (7) | N2—C18—C23 | 123.35 (18) |
C6—Er—C2 | 88.77 (7) | C18—C19—N1 | 106.68 (18) |
C1—Er—C2 | 31.23 (7) | C18—C19—C24 | 128.14 (18) |
C4—Er—C2 | 59.11 (7) | N1—C19—C24 | 125.18 (18) |
C11—Er—C7 | 99.16 (7) | N2—C20—C21 | 110.60 (16) |
C13—Er—C7 | 151.40 (8) | N2—C20—C22 | 109.92 (17) |
C10—Er—C7 | 89.42 (7) | C21—C20—C22 | 111.38 (19) |
C15—Er—C7 | 145.51 (8) | N2—C20—H20 | 108.3 |
C14—Er—C7 | 176.77 (8) | C21—C20—H20 | 108.3 |
C12—Er—C7 | 122.08 (8) | C22—C20—H20 | 108.3 |
C5—Er—C7 | 59.45 (7) | C20—C21—H21A | 109.5 |
C16—Er—C7 | 117.51 (8) | C20—C21—H21B | 109.5 |
C9—Er—C7 | 96.86 (7) | H21A—C21—H21B | 109.5 |
C8—Er—C7 | 31.09 (7) | C20—C21—H21C | 109.5 |
C6—Er—C7 | 31.04 (7) | H21A—C21—H21C | 109.5 |
C1—Er—C7 | 59.23 (7) | H21B—C21—H21C | 109.5 |
C4—Er—C7 | 80.19 (7) | C20—C22—H22A | 109.5 |
C2—Er—C7 | 80.20 (7) | C20—C22—H22B | 109.5 |
C11—Er—C3 | 148.53 (8) | H22A—C22—H22B | 109.5 |
C13—Er—C3 | 100.45 (7) | C20—C22—H22C | 109.5 |
C10—Er—C3 | 177.23 (7) | H22A—C22—H22C | 109.5 |
C15—Er—C3 | 101.54 (7) | H22B—C22—H22C | 109.5 |
C14—Er—C3 | 93.07 (7) | C18—C23—H23A | 109.5 |
C12—Er—C3 | 120.75 (8) | C18—C23—H23B | 109.5 |
C5—Er—C3 | 59.19 (7) | H23A—C23—H23B | 109.5 |
C16—Er—C3 | 122.59 (8) | C18—C23—H23C | 109.5 |
C9—Er—C3 | 150.25 (8) | H23A—C23—H23C | 109.5 |
C8—Er—C3 | 80.06 (7) | H23B—C23—H23C | 109.5 |
C6—Er—C3 | 80.08 (7) | C19—C24—H24A | 109.5 |
C1—Er—C3 | 59.24 (7) | C19—C24—H24B | 109.5 |
C4—Er—C3 | 30.80 (7) | H24A—C24—H24B | 109.5 |
C2—Er—C3 | 30.87 (7) | C19—C24—H24C | 109.5 |
C7—Er—C3 | 87.93 (7) | H24A—C24—H24C | 109.5 |
C17—N1—C19 | 108.58 (16) | H24B—C24—H24C | 109.5 |
C17—N1—C25 | 121.53 (16) | N1—C25—C27 | 111.65 (16) |
C19—N1—C25 | 129.87 (17) | N1—C25—C26 | 111.13 (16) |
C17—N2—C18 | 108.34 (16) | C27—C25—C26 | 113.51 (18) |
C17—N2—C20 | 126.07 (17) | N1—C25—H25 | 106.7 |
C18—N2—C20 | 125.56 (16) | C27—C25—H25 | 106.7 |
C8—C1—C2 | 134.2 (2) | C26—C25—H25 | 106.7 |
C8—C1—Er | 74.29 (13) | C25—C26—H26A | 109.5 |
C2—C1—Er | 74.50 (12) | C25—C26—H26B | 109.5 |
C8—C1—H1 | 112.9 | H26A—C26—H26B | 109.5 |
C2—C1—H1 | 112.9 | C25—C26—H26C | 109.5 |
Er—C1—H1 | 133.7 | H26A—C26—H26C | 109.5 |
C3—C2—C1 | 135.2 (2) | H26B—C26—H26C | 109.5 |
C3—C2—Er | 75.16 (12) | C25—C27—H27A | 109.5 |
C1—C2—Er | 74.27 (13) | C25—C27—H27B | 109.5 |
C3—C2—H2 | 112.4 | H27A—C27—H27B | 109.5 |
C1—C2—H2 | 112.4 | C25—C27—H27C | 109.5 |
Er—C2—H2 | 133.7 | H27A—C27—H27C | 109.5 |
C4—C3—C2 | 135.3 (2) | H27B—C27—H27C | 109.5 |
C4—C3—Er | 73.95 (12) | ||
C8—C1—C2—C3 | 0.1 (4) | C17—N2—C18—C19 | −0.4 (2) |
C1—C2—C3—C4 | −2.8 (4) | C20—N2—C18—C19 | −178.42 (17) |
C2—C3—C4—C5 | 1.4 (4) | C17—N2—C18—C23 | 179.20 (19) |
C3—C4—C5—C6 | 3.1 (4) | C20—N2—C18—C23 | 1.2 (3) |
C4—C5—C6—C7 | −3.2 (4) | N2—C18—C19—N1 | 0.3 (2) |
C5—C6—C7—C8 | −1.1 (4) | C23—C18—C19—N1 | −179.3 (2) |
C2—C1—C8—C7 | 0.1 (4) | N2—C18—C19—C24 | −179.1 (2) |
C6—C7—C8—C1 | 2.4 (4) | C23—C18—C19—C24 | 1.3 (4) |
C16—C9—C10—C11 | −1.7 (5) | C17—N1—C19—C18 | 0.0 (2) |
C9—C10—C11—C12 | 0.3 (5) | C25—N1—C19—C18 | 178.69 (18) |
C10—C11—C12—C13 | 0.8 (5) | C17—N1—C19—C24 | 179.4 (2) |
C11—C12—C13—C14 | −0.4 (5) | C25—N1—C19—C24 | −1.9 (3) |
C12—C13—C14—C15 | 0.3 (5) | C17—N2—C20—C21 | 19.8 (3) |
C13—C14—C15—C16 | −1.4 (5) | C18—N2—C20—C21 | −162.46 (19) |
C14—C15—C16—C9 | 1.2 (5) | C17—N2—C20—C22 | −103.6 (2) |
C10—C9—C16—C15 | 0.8 (5) | C18—N2—C20—C22 | 74.1 (2) |
C19—N1—C17—N2 | −0.2 (2) | C17—N1—C25—C27 | −122.8 (2) |
C25—N1—C17—N2 | −179.05 (16) | C19—N1—C25—C27 | 58.6 (3) |
C18—N2—C17—N1 | 0.4 (2) | C17—N1—C25—C26 | 109.4 (2) |
C20—N2—C17—N1 | 178.39 (17) | C19—N1—C25—C26 | −69.2 (3) |
Experimental details
Crystal data | |
Chemical formula | (C11H21N2)[Er(C8H8)2] |
Mr | 556.85 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 133 |
a, b, c (Å) | 12.7879 (12), 8.7333 (8), 21.531 (2) |
β (°) | 94.100 (3) |
V (Å3) | 2398.5 (4) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 3.51 |
Crystal size (mm) | 0.33 × 0.25 × 0.14 |
Data collection | |
Diffractometer | Bruker SMART 1000 CCD |
Absorption correction | Multi-scan (SADABS; Bruker, 1998) |
Tmin, Tmax | 0.390, 0.639 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 46432, 7325, 6213 |
Rint | 0.031 |
(sin θ/λ)max (Å−1) | 0.714 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.020, 0.042, 1.11 |
No. of reflections | 7325 |
No. of parameters | 281 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 1.24, −0.88 |
Computer programs: SMART (Bruker, 1998), SAINT (Bruker, 1998), SAINT, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), XP (Siemens, 1994), SHELXL97.
Er—C11 | 2.596 (2) | Er—C8 | 2.627 (2) |
Er—C13 | 2.599 (2) | Er—C6 | 2.627 (2) |
Er—C10 | 2.600 (2) | Er—C1 | 2.633 (2) |
Er—C15 | 2.600 (2) | Er—C4 | 2.634 (2) |
Er—C14 | 2.602 (2) | Er—C2 | 2.636 (2) |
Er—C12 | 2.602 (2) | Er—C7 | 2.636 (2) |
Er—C5 | 2.6080 (19) | Er—C3 | 2.651 (2) |
Er—C16 | 2.611 (2) | N1—C17 | 1.330 (3) |
Er—C9 | 2.615 (2) | N2—C17 | 1.335 (2) |
N1—C17—N2 | 109.26 (17) |
D—H···A | Distance H···A (Å) | Angle D—H···A (°) | Symmetry code |
C25—H25···Cg(C1–C8) | 2.27 | 178 | |
C17—H17···Cent(C4—C5) | 2.33 | 169 | |
C20—H20···Cent(C10—C11) | 2.58 | 140 | (0.5+x, 0.5-y, 0.5+z) |
C22—H22C···Cent(C12—C13) | 2.67 | 151 | (0.5+x, 0.5-y, 0.5+z) |
Notes: C—H distances are normalized to 1.08Å, Cg is the centre of gravity of a ring and Cent is the mid-point of a bond. |
After the synthesis of uranocene [(COT)2U] (COT = cyclooctatetraenyl, (C8H8)2-) by Streitwieser & Müller-Westerhoff (1968), bis-cyclooctatetraene complexes of divalent lanthanides were reported by Hayes & Thomas (1969). Streitwieser isolated trivalent lanthanide complexes of the type [K(COT)2Ln] (Ln = Y, La, Ce, Pr, Nd, Sm, Gd, Tb) (Mares et al., 1970; Streitwieser et al., 1973; Hodgson et al., 1973) using the same methodology as for the preparation of uranocene. Later, [K(COT)2Ln] complexes of ytterbium (Boussie et al., 1991) and lutetium (Schumann et al., 1993) were reported. In 1991 Chen synthesized an erbium complex with a tetralayer sandwich structure in which the adjacent Er3+ and K+ ions are bridged by η8-cyclooctatetraenyl groups (Xia et al., 1991). Here we report the anionic mononuclear sandwich complex of bis(cyclooctatetraenyl)erbium(III) with the carbenium cation 1,3- diisopropylimidazolium (Fig. 1).
The compound crystallizes without imposed symmetry. The coordination polyhedron is formed by two planar eight-membered rings (r.m.s. deviation 0.016, 0.006 Å) in an almost parallel arrangement with an interplanar angle of 2.21 (9)°. The perpendicular distances of the Er atom from the C8 planes are 1.8809 (7) and 1.8476 (8) Å. The angle cent1—Er—cent2 (cent = centroid) is 178°. The rings are eclipsed, as shown by torsion angles, e.g. C1—Cg1—Cg2—C12 = -3°, where Cg are ring centres of gravity. The individual Er—C bond lengths range from 2.596 (2)–2.651 (2) Å, which is comparable with Er—C(η8) [2.569 (14)–2.660 (19) Å], Er—C(η5) [2.629 (15)–2.654 (13) Å] reported for (COT)Er(µ-COT)K(µ-COT)Er(µ-COT)K(THF)4 (Xia et al. 1991), and (µ5-C5H5)2Er(µ-CH3)2Li(tmeda) (tmeda = tetramethylethylenediamine) (Schumann et al. 1985) respectively. In the imidazolium ion, the N—C distances [1.330 (3) and 1.335 (2) Å] are slightly shorter than those of 1,3-di(1-adamantyl)imidazol-2-ylidene reported by Arduengo et al. (1991) [1.367 (2) and 1.373 (2) Å], indicating delocalization of the positive charge over the N1—C17—N2 unit.
The packing involves several short interionic ("charge-assisted") contacts, principally from the more acidic H atoms H17, H20 and H25 (but also from H22C). The C—H bond distances were normalized to 1.08Å to calculate the contact distances. The shortest is from H25 to the centroid of C1–8, with H···cent 2.27 Å, C—H···cent 178°. The other contacts are best described as involving individual bonds as acceptors: C17—H17···C4,C5 [H···C 2.55, 2.31 Å, angles 156, 165°]; C20—H20···C10,C11 [2.73, 2.62 Å, 143, 133°, operator 1/2 + x, 1/2 - y, 1/2 + z]; C22—H22C—C12,C13 [2.80, 2.73 Å, 138, 163°, same operator]. The net effect is to connect the residues to form a chain parallel to (101) (Fig. 2). Between chains, a short C22···C22 contact is observed [3.168 (4) Å, operator 1 - x,1 - y,1 - z].