Synthese, struktur und eigenschaften von Grignard-Verbindungen mit N,N-dimethylaminoethyl-substituierten cyclopentadienyl-systemen

The Hemilabile [2-(Dimethylamino)ethyl]cyclopentadienyl Ligand and Nickel: Preparation and Structural Analysis of New Cationic and Neutral Complexes

“…[2] Although the signals of the Cp protons appear in the same region as in 1b, the signals of the H atoms in the amino moiety are both shifted downfield compared with those of free Cp N H. Moreover, the resonances for the two methylene groups in 4 are very close to each other which is typical for a free, uncoordinated side-chain as was reported for [Cp* N Ni(CO)] 2 , [12] and [Cp N Ni(CO)] 2 , [2] and confirmed with the preparation of 5. In fact, this data and the fact that two equivalents of PPh 3 were used in the reaction and that species like [Cp N Ni(PPh 3 ) 2 ] ϩ were detected in the FAB mass spectra of 4, led us to the initial conclusion that the new compound was of the formula [Cp N Ni(PPh 3 ) 2 ] ϩ PF 6 Ϫ , with a dangling amino side-chain very similar to that in 5.…”

“…[2,12] All proton signals of the ethylene bridge appear in the same region at δ ഠ 2.48 (almost identical to the values for free Cp N H of δ ഠ 2.47) due to a coincidentally small difference in their chemical shifts. This results in a badly resolved muliplet.…”

Cyclopentadienyl Complexes of the Alkaline Earths in Light of the Periodic Trends

“…The Mg-bromide with a pendant amine is either a solvent-free dimer or a THF-solvated monomer. [84] The Mg-alkyls with two pyrazoles are initiators for the polymer-ization of cyclic esters. [85] The THF-bound monomeric Ca-and Sr-HMDS complexes have a sila-linked imidazolin-2-imine donor.…”

“…There are some [Cp'MX] with pendant donors from the Cp'rings (Figure 8). The Mg‐bromide with a pendant amine is either a solvent‐free dimer or a THF‐solvated monomer [84] . The Mg‐alkyls with two pyrazoles are initiators for the polymerization of cyclic esters [85] .…”

A Functionalized Cyclooctatetraene as Ligand in Organolanthanide Chemistry

“…Today, group 4 metal complexes containing an amido cyclopentadienyl ligand have gained considerable importance as homogeneous polymerization catalysts in the presence of methyl alumoxane . In addition to the complexes used for catalytic applications a huge number of main group and transition metal complexes containing the cyclopentadienyl ligand (or its derivatives) in which at least one additional coordination site is tethered via a bridge to the five-membered ring such as BR 2 , −CHCH 2 , NR, ,, NR 2 , PR 2 , O, OR, and SR are also known …”