Structure of a zirconoxyborane having a zirconium-fluorine-carbon bridge

η2‐Iminoacyl and η2‐Acyl Monocyclopentadienyl Tantalum Complexes Bearing Oxo and Oxo‐Borane Ligands

“…All the values of the bond lengths and angles of compound 2d are very close to the corresponding bond lengths and angles found for the parent compound [TaCp*Cl{η 2 -C(Me)=NAr}(O)] [10] except for the Ta [ [21][22][23][24][25][26][27][28][29][30][31] The Ta-O bond in 2d is longer than that in the oxo-borane compound [TaCp*Cl 2 {O·B(C 6 F 5 ) 3 }] [21] [1.784(2) Å]. This bond length is similar to the lower end of the range of Ta-O bond lengths for compounds with Ta-O-Ta bridges (1.82-2.10 Å) [32][33][34][35] and with terminal Ta-OH bonds (1.85-1.97 Å).…”

“…[10,11] The versatility and potential applications of all these results determined by the R and X substituents of the imido complexes [TaCp*MeX(NR)] led us to extend our studies to similar insertion reactions of CNR and CO into the Taalkyl bonds of the related oxo-borane compounds [TaCp*X 2 {O·B(C 6 F 5 ) 3 }] that have recently been isolated. [21] Results and Discussion [21][22][23][24][25][26][27][28][29][30][31] and the 1 H NMR spectra with the monosubstitution of only one of the alkyl ligands. These pale yellow complexes are air and thermally stable in solution.…”

“…The Ta have values that are normally seen for these types of compounds. [21][22][23][24][25][26][27][28][29][30][31] The whole set of angles and bond lengths of the [Ta-(η 2 -acyl)] group is in line with compounds of this type [1] and is similar to those found in the other two tantalum-acyl complexes for which X-ray structures are known, [TaCp*Me{η 2 -C(CH 2 CMe 2 Ph)=O}{N(2,6-Me 2 C 6 H 3 )}] [39] and [TaCp*Cl 3 {η 2 -C(CH 2 CMe 3 )=O}]. [40] However, in the particular case of the isostructural imido derivative [TaCp*Me{η The insertion of a second CNAr or CO molecule into these new acyl and iminoacyl oxo-borane complexes was not observed, in contrast with the behaviour observed for the analogous tert-butyl imido complexes.…”

Surface organometallic chemistry: a route to well-defined boron heterogeneous co-catalyst for olefin polymerisation

“…According to the silica specific area (200 m 2 g -1 ), this projection corresponds to a theoretical value of 0.24 w% of boron on a saturated surface. This result Al spectroscopic and analytic data, as well as the similarities with those of molecular compounds [HNEt 2 Ph] + [(C 6 F 5 ) 3 BOR] -(R = H, SiPh 3 , Si 8 O 12 (c-C 5 H 9 ) 7 ) [17, 36,39] confirmed the already proposed [6,7,9] structure for 2 (Eq. (8)).…”

The Coordination Chemistry of the CF Group of Fluorocarbons: Thermodynamic Data and Ab Initio Calculations on CF-Metal Ion Interactions

“…Apart from two dynamic NMR studies by Siedle et al [11] and Erker et al, [12] little is known about the energetics of CF ± metal interactions.…”