Metal-mediated rearrangement of 1,2-diphenylhydrazine to ortho-semidine upon reaction with dichlorotris(triphenylphosphine)ruthenium(II).

Reaction between RuCl2(PPh3)3 and 1,2-diphenylhydrazine resulted in rearrangement and coordination of ortho-semidine. The product, RuCl2(PPh3)2(κ2-NH2-1,2-C6H4-NHPh), was characterized spectroscopically and the molecular structure was conclusively determined using X-ray crystallography. Computational chemistry was employed to probe the energetics surrounding the rearrangement reaction and product.

Robust Olefin Metathesis Catalyst Bearing a Tridentate Hemilabile NHC Ligand.

An olefin metathesis catalyst bearing a tridentate hemilabile N-heterocyclic carbene (NHC) ligand was synthesized and characterized. The solid-state crystal structure reveals coordination from all three donation sites of the NHC ligand, giving rise to a stable 18-electron complex. Catalytic activity in three standard metathesis reactions was demonstrated, revealing our catalyst to be particularly long lived and highly selective in the self-metathesis of 1-decene. Although the catalyst in this work initiates more slowly than its second-generation counterparts, it was shown to have high thermal stability, yielding peak performances at higher temperatures. The unique ligand framework of this catalyst may serve as a template for the synthesis of analogous catalysts with improved efficiencies.