Titanocen‐ und Zirconocen(diazadien)‐Komplexe: Darstellung, Charakterisierung und Struktur

Abstract

Titanocene‐ and Zirconocene(diazadiene) Complexes: Preparation, Characterization, and Structure By treating Cp 2 MCl 2 (M = Ti, Zr) with magnesium in the presence of the diazadienes R 1 N = CR 2 CR 2  NR 1 (R 1  R 2  Ph: 1a ; R 1  Ph, R 2  Me: 1b ) metallocene complexes of formula Cp 2 ) (M  Ti: 2a , b ; M  Zr: 3a , b) have been obtained in good yields. 2a–3b exhibit dynamic NMR spectra indicating a rapid intramolecular migration of the bent metallocene unit Cp 2 M from one “face” of the reduced diazadiene to the other. From the 1 H‐NMR Cp‐coalescence ΔG‡ values for the activation barrier of this automerization process have been obtained. Complex 3a was characterized by X‐ray diffraction. The five‐membered metallacyclic ZrNCCN ring system adopts an “envelope”‐conformation.