research papers
The crystal structure of pentamethylcyclopentadienyllithium, [Li(C10H15)] (LiCp*), has been determined from a high-resolution powder pattern by modelling and the maximum entropy method (MEM). The compound crystallizes in space group R3m with lattice parameters a = b = 14.7711 (5), c = 3.82206 (6) Å and V = 722.19 (4) Å3 (Z = 3). LiCp* forms polymeric `multidecker' chains along the c axis. The pentamethylcyclopentadienyl anions are coplanar with each other and show threefold rotational disorder. The MEM calculations did not only confirm the structural model and the type of disorder, but also discovered additional symmetry compared with the Rietveld analysis. This is the first solid-state structure of a Lewis-base-free alkali metal Cp* compound.
Supporting information
Crystallographic Information File (CIF) | |
Rietveld powder data file (CIF format) | |
Rietveld powder data file (CIF format) |
CCDC reference: 131761
Computing details top
(Model) top
Crystal data top
C10H15Li | V = 722.19 (4) Å3 |
Mr = 142.17 | Z = 3 |
Trigonal, R3m | Dx = 0.980 Mg m−3 |
Hall symbol: R 3 -2" | Synchrotron radiation, λ = 0.84979 Å |
a = 14.7711 (5) Å | T = 293 K |
c = 3.82206 (6) Å | × × mm |
Crystal data top
C10H15Li | V = 722.19 (4) Å3 |
Mr = 142.17 | Z = 3 |
Trigonal, R3m | Synchrotron radiation, λ = 0.84979 Å |
a = 14.7711 (5) Å | T = 293 K |
c = 3.82206 (6) Å | × × mm |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
x | y | z | Uiso*/Ueq | Occ. (<1) | |
Li | 0.6666 | 0.3333 | 0.5 | 0.060 | |
C11 | 0.714 | 0.427 | 0 | 0.062 (2) | 0.3333 |
C12 | 0.758 | 0.362 | 0 | 0.062 (2) | 0.1666 |
C13 | 0.677 | 0.258 | 0 | 0.062 (2) | 0.1666 |
C21 | 0.774 | 0.547 | 0 | 0.046 (3) | 0.3333 |
C22 | 0.876 | 0.400 | 0 | 0.046 (3) | 0.1666 |
C23 | 0.689 | 0.160 | 0 | 0.046 (3) | 0.1666 |
Experimental details
Crystal data | |
Chemical formula | C10H15Li |
Mr | 142.17 |
Crystal system, space group | Trigonal, R3m |
Temperature (K) | 293 |
a, c (Å) | 14.7711 (5), 3.82206 (6) |
V (Å3) | 722.19 (4) |
Z | 3 |
Radiation type | Synchrotron, λ = 0.84979 Å |
µ (mm−1) | ? |
Crystal size (mm) | × × |
Data collection | |
Diffractometer | ? |
Absorption correction | ? |
No. of measured, independent and observed (?) reflections | ?, ?, ? |
Rint | ? |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | ?, ?, ? |
No. of reflections | ? |
No. of parameters | ? |
No. of restraints | ? |
Δρmax, Δρmin (e Å−3) | ?, ? |