Enforced η<sup>1</sup>-Fluorenyl and Indenyl Coordination to Zirconium: Geometrically Constrained and Sterically Expanded Complexes Derived from the Bifunctional (FluPPh<sub>2</sub>NAr)<sup>−</sup> and (IndPPh<sub>2</sub>NAr)<sup>−</sup> Ligands
The (FluPPh2NAr) and (IndPPh2NAr) ligands 2a–c and 4a–c (a, Ar = Ph; b, R = DIPP; c, = Mes) were readily prepared by Staudinger reactions between aryl azides and Flu/Ind diphenylphosphines, and they were coordinated to zirconium via toluene elimination. The propensity of the pendent phosphazene group to enforce low hapticity of the Flu and Ind rings in the ensuing complexes has been demonstrated experimentally