Piano stool complexes containing the bulky pentaphenylcyclopentadienyl(C5Ph5) ligand: Preparation, characterization and X-ray structure of C5Ph5Zr(N(CH3)2)3 (I)

Synthesis and Complexation Behavior of Indenyl and Cyclopentadienyl Ligands Functionalized with a Naphthyridine Unit

“…In addition to that, the 1 H NMR shifts of the naphthyridine unit are similar to those of the free ligand 5 . This is in agreement with a noncoordinating naphthyridine unit leading to a three-legged piano stool arrangement . However, we cannot exclude the possibility of a weak naphthyridine–Zr interaction combined with a fast exchange of the NMe 2 units.…”

“…One of them is coordinated to the Zr center and thus completes its coordination sphere to an octahedral environment where the indenyl unit occupies one coordination site (see Figure ). The Zr–N distance is within the usual range of such interactions . We have tested complex 14 as an olefin polymerization catalyst.…”

“…This is in agreement with a noncoordinating naphthyridine unit leading to a threelegged piano stool arrangement. 18 However, we cannot exclude the possibility of a weak naphthyridine−Zr interaction combined with a fast exchange of the NMe 2 units. A similar behavior has been observed by Kol et al for a closely related zirconium complex where X-ray crystallography showed a very long Zr−N interaction between the additional N-donor and the zirconium atom.…”

Group IV Metal Dimethylamido Complexes of the Chiral Cyclopentadienyl‐type Ligand (CpC)–1

“…Solvents used in reactions were dried by standard methods and degassed prior to use. The 1 H and 13 C NMR spectra were recorded on a Bruker AVANCE 400 ( 1 H, 400 MHz; 13 C, 101). The chemical shifts are referenced to internal solvent resonances.…”

“…[12] In 2005 Tikkanen et al synthesized (η 5 -C 5 Ph 5 )Zr(NMe 2 ) 3 possessing the very bulky pentaphenylcyclopentadienyl ligand. [13] Treatment of this compound with (R)-(+)-1-phenylethanol was considered to lead to a monosubstituted alkoxide complex with potential application in stereospecific catalysis. In this case and in the case of many other cyclopentadienyl complexes, chirality does not result from the cyclopentadienyl ligand itself but from the addition of a chiral substituent or the SHORT COMMUNICATION generation of an ansa-bridged system.…”