New Chelating Pt(II) Complexes For C - H Bond Activation

Abstract

New chelating ligand systems were made and further complexed with platinum centers to give complexes for hydrocarbon C H activation. The first of the complexes was the [(1,1 -dimethyl-3,3 -methylene diimidazoline-2,2 -diylidine) platinum(II) dichloride]. This was made starting with 1-methylimidazole and through a series of reaction giving the final product. Attempts to synthesize another bis-carbene complex of similar skeleton, but with tert-Btuyl groups instead of the methyl groups failed to give significant and useable results. The second was the dimethyl (glyoxal-(4-methoxy terphenyl imine) platinum(II) complex having sterically demanding side groups. The ligand was synthesized starting with 4-bromoanisole, going through Grignard reaction, Suzuki coupling, condensation reaction and finally complexing to a metal center. This complex was protonated under different conditions i.e. different temperatures and in different solvents/ solvent mixtures to give the cationic and dicationic species with irreversible loss of methane. All the products were characterized by different spectroscopic methods including NMR, MS, UV and IR. Element analysis was also used as confirmatory test in addition to spectroscopy.