Ruthenocene Precursors for Ruthenium-Containing Thin-Film Deposition: An Example of Solvent Nucleophilic Attack on Fulvene

A new series of ruthenocene complexes were prepared from RuCl3·xH2O and 6,6-dimethylfulvene as potential precursors for thin-film deposition. The formation of these complexes was the result of an unforeseen nucleophilic attack of the solvent molecules (alcohols/amines) on the 6,6-dimethylfulvene ligand during the reaction. Complexes [RuII(C5H4C(CH3)2OCH3)2] (1), [RuII(C5H4C(CH3)2OC2H5)2] (2), [RuII(C5H4C(CH3)2N(CH3)2)2] (3), and [RuII(C5H4C(CH3)2N(CH2CH3)2)2] (4) were isolated in pure form and characterized by Fourier transform (FT) infrared and FT nuclear magnetic resonance spectroscopy as well as elemental and thermogravimetric (TG) analyses. Crystallographic studies of complexes 1–3 revealed a monomeric ruthenocene structure for all complexes and showed that the deprotonated alkylalkoxide or dialkylamide of the solvent molecule was attached to the exocyclic carbon of the fulvene ligand. Although the complexes were formed as ruthenocenes instead of the expected ruthenium fulvene complexes, they all disp...