10.1021/om3002119
The study investigates the unusual Si?H bond activation and formation of cationic scandium amide complexes from a mono(amidinate)-ligated scandium bis(silylamide) complex, as well as their performance in isoprene polymerization. The researchers started with the neutral mono(amidinate) scandium bis(silylamide) complex [PhC(N-2,6-iPr2C6H3)2]Sc[N(SiHMe2)2]2 (1), which was synthesized through amine elimination of scandium tris(silylamide) complex Sc[N(SiHMe2)2]3(THF) with the amidine [PhC(N-2,6-iPr2C6H3)2]H. When activated with [Ph3C][B(C6F5)4], complex 1 generated the cationic amidinate scandium amide complex [{PhC(N-2,6-Pr2C6H3)2}ScN{SiHMe2}{SiMe2N(SiHMe2)2}(THF)2][B(C6F5)4] (2). The addition of excess AlMe3 to complex 1 resulted in the formation of the amidinate Sc/Al heterometallic methyl complex [PhC(N-2,6-iPr2C6H3)2]Sc[(μ-Me)2AlMe2]2 (3). These complexes were characterized by various techniques. In terms of polymerization performance, the 1/[Ph3C][B(C6F5)4] system showed 3,4-selective activity toward isoprene polymerization, while the addition of AlMe3 switched the regioselectivity to cis-1,4-selective.
10.1039/b106243n
The study focuses on the synthesis and characterization of a series of ruthenium(II) complexes containing bulky, functionalized trialkylphosphines, specifically tBu2PCH2XC6H5, as ligands. These complexes were prepared through reductive routes or ligand replacement reactions, and their structures and properties were investigated. The chemicals used in the study include ruthenium(III) chloride hydrate (RuCl3·3H2O), trialkylphosphines tBu2PCH2XPh (where X = CH2 or OCH2), isoprene, and various other reagents such as AgPF6, acetone, CH3CN, and PMe3. These chemicals served as starting materials, ligands, reducing agents, and solvents in the preparation of the complexes. The purpose of these chemicals was to create a variety of ruthenium(II) complexes that can be used as catalysts in olefin metathesis reactions, with the aim of modifying the coordination sphere of the metal to find potentially better catalysts for these reactions. The study also explored the reactivity of these complexes towards various substrates, such as acetylene, to form new compounds like allenylidene and vinylidene complexes, which were further tested for their catalytic activity in ring-opening metathesis polymerization (ROMP) of cyclooctene.
F+,
T
F+:Highly flammable;
