920975-66-2Relevant academic research and scientific papers
Synthesis and structure of 6-aminofulvene-2-aldiminate complexes
Willcocks, Alexander M.,Gilbank, Alexander,Richards, Stephen P.,Brayshaw, Simon K.,Kingsley, Andrew J.,Odedra, Raj,Johnson, Andrew L.
, p. 937 - 948 (2011/04/24)
We report here a synthetic route to bis(N,N'-aryl)-6-aminofulvene-2- aldimine (AFA) ligand systems, specifically Ph2-AFAH and Dip 2-AFAH. The synthesis and structural characterization of a series of Cu(I) complexes [(Ph2-AFA)-Cu(CNPh)2](2), [(Ph 2-AFA)Cu(CNPr)] (3), and [(Dip2-AFA)Cu(CNiPr)] (4), from the reaction of the corresponding lithiated AFA systems with Cu-Cl derivatives are reported; notably in the case of [(Ph2-AFA)Cu(CNPh)2] studies have revealed the existence of two structural isomers (2a and 2b), both of which can be isolated and structurally characterized. Density functional theory (DFT) calculations suggest that the two crystal forms are comparatively close in energy, and geometry optimization reveals a convergence of these two forms to a geometry that more closely resembles the solid-state structure of isomer 2b, having a CH ... π interaction. The reactions of the AFA compounds Ph2-AFAH and Dip2-AFAH with ZnMev and AlMe 3 have also been investigated, and the results of these reactions are described here.
Ambidentate character of the 6-aminofulvene-2-aldiminate ligand containing both diimine and cyclopentadienyl donors
Bailey, Philip J.,Melchionna, Michele,Parsons, Simon
, p. 128 - 135 (2008/10/09)
The 6-aminofulvene-2-aldiminate (AFA) ligand contains both cyclopentadienyl and diimine donors. The ligand preferentially coordinates to transition metals via the nitrogen atoms; however once these are occupied, the cyclopentadienyl ring may be coordinated to a Cp*Ru+ unit, providing bi- and trimetallic species. In the tetrahedral [Zn(Ph2AFA)2] (2) the metal is located approximately in the planes of the two ligands; however in the square-planar [Pd(Ph2AFA)2] (1) there is a severe distortion of the coordination and the metal is located almost 1.3 A out of the planes of the two ligands. This situation arises to avoid the steric interaction of the ligand phenyl substituents. Treatment of 2 with [Cp*Ru(NCMe)3][BF4] gives [Cp *Ru(η5-Ph2AFA)] (3), providing the first example of the cyclopentadienyl coordination of an AFA ligand in which the nitrogen donors are vacant, and it is thought to form as a result of the fragmentation of an intermediate mixed Zn/Ru species. The X-ray structure of 3 provides some evidence for an interaction between the Ru center and one of the exocyclic carbon atoms, thus suggesting a fulvene form of the ligand in this complex. Similar treatment of 1 with [Cp*Ru(NCMe)3][BF4] provides a trimetallic PdRu2 species (4) in which both of the cyclopentadienyl rings in the complex 2 are coordinated to Ru. The complex [(Ph2AFA)Pd(Me)PPh3] (5) is formed on treatment of [(COD)PdMe(Cl)] with NaPh2AFA in the presence of PPh3, and preliminary investigations have shown that its activation with [Ni(COD) 2] as a phosphine scavenger provides species active toward ethylene oligomerization and polymerization.
