Transition metal cyclopentadienyl complexes bearing perfluoro-4-tolyl substituents

Hyperfine Interactions and Metal Atom Dynamic Effects of Pentafluorophenyl Substituents on Ferrocene Complexes

“…Although there is a fair amount of scatter in the data, the high temperature limiting slope of d(ln A)/dT is -(6.95±0.12)×10 -3 K -1 with an r value of 0.998 for 10 data points. The X-ray data at 100 K have been reported by Deck et al 13 and the comparison of the MES and X-ray data lead to ₣ X,100 = 0.89 (5) and ₣ M,100 = 0.70(1) in modest agreement with each other. Again, making the assumption that the linear extrapolation leads in the low temperature limit ₣ M →0, the mean square amplitudes of vibration of the iron atom at the same temperature for 1 and 2 are nearly identical (see above), so that replacement of a phenyl ring F by a CF 3 group has essentially no effect on the iron atom dynamics.…”

“…In the present study, a number of compounds have been examined, including C 2 2 H 8 F 10 Fe, 2 (1); C 2 4 H 8 F 14 Fe, 3 (2); C 24 H 14 F 8 Fe, (3); C 42 H 22 F 20 Fe•CHCl 3 , 4 (4); C 46 H 4 F 30 Fe•C 6 H 6 , 5 (5); C 38 H 16 F 14 Fe 2 , 6 (6); and C 30 H 6 F 16 FeN 4 , 7 (7). For enhanced clarity, the structures of these compounds are collected in scheme 1.…”

Fluorine-Centered Halogen Bonding: A Factor in Recognition Phenomena and Reactivity

“…A close intermolecular contact, R–F---B, where B is a basic site on a neighboring molecule, can be interpreted as a σ-hole interaction if the F---B separation is less than (or very close to) the sum of the respective van der Waals radii and the R–F–B angle is in the vicinity of 180°. This combination has been observed on many occasions, ,,− as shall be seen in Sections III and IV. (The R–F–B angle may deviate somewhat from 180° due to secondary interactions within the crystal lattice.…”

2,3-Bis[2-(trifluoromethyl)phenylimino]butane

“…The bond lengths found in (I) do not indicate a strong electron-withdrawing influence by the trifluoromethyl groups, although the F-C-F bond angles are smaller than expected (Deck et al, 2006). Selected geometric parameters are listed in Table 1.…”