Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published June 1, 1996 | Published + Supplemental Material
Journal Article Open

A tribenzylidenemethane–tantalum compound: some experiences with 'inversion twinning'

Abstract

The six-electron-donating ligand tribenzylidenemethandiide has been used to form a tantalum (group 5) mimic, (η^5-cyclopentadienyl)(η^4-tribenzylidenemethandiide)dimethyltantalum, of a group 4 bent metallocene. The material crystallizes with two molecules in the asymmetric unit with quite different packing arrangements, although the overall structures of the two are similar. The Cp and methyl ligands are disordered about a threefold axis. Crystal data: [Ta{(C_7H_6)_3C}(C_5H_5)(CH_3), trigonal P31c, with a = 12.681 (3), c = 16.124 (5) Å, V = 2245.5 (7) Å^3, T = 293 K, Z = 4, M_r = 558.47, D_x = 1.65 g cm^(-3), F(000) = 1104, Mo Kα, λ = 0.71073 Å, µ = 4.91 mm^(-1), R = 0.020 for 1319 reflections with F_o > 4σ(F_o); S = 2.18. Because of crystal decay, three separate crystals were needed for a full data set. These polar (but achiral) crystals showed apparently differing amounts of inversion twinning, leading to problems in accurately merging the three data sets and refining the structure. These problems are discussed briefly.

Additional Information

© 1996 International Union of Crystallography. Received 24 April 1995; accepted 25 September 1995. We thank Ken Hardcastle and Larry Henling for help with the SHELX programs and data collection. We also thank the referees and the Co-editor for many helpful suggestions.

Attached Files

Published - bk0026.pdf

Supplemental Material - bk0026.cif

Files

bk0026.pdf
Files (436.5 kB)
Name Size Download all
md5:90319d327c62720383e7c4ddbc8abba4
6.9 kB Download
md5:37f3d28945801fb1180ee1b7abc33a4f
429.6 kB Preview Download

Additional details

Created:
August 18, 2023
Modified:
October 24, 2023