Accessing Mononuclear Triphenylcyclopentadienyl Lanthanide Complexes by Using Tridentate Nitrogen Ligands: Synthesis, Structure, Luminescence, and Catalysis

Abstract

A series of mononuclear aryl-substituted cyclopentadienyl complexes [CpPh3LnCl2(Me3tach)] (Ln = Tb (4), Ln = Nd (5)), [CpPh2ArTbCl2(Me3tach)] (6), and [CpPh3LnCl2(Me3tacn)] (Ln = Tb (7), Ln = Nd (8), CpPh3: 1,2,4-triphenylcyclopentadienyl, CpPh2Ar: 1,2-diphenyl-4-(o-methoxyphenyl)cyclopentadienyl, Me3tach: 1,3,5-trimethyl-1,3,5-triazacyclohexane, Me3tacn: 1,4,7-trimethyl-1,4,7-triazacyclononane) have been synthesized from polynuclear precursors, using cyclic tridentate nitrogen-based ligands to prevent formation of ate complexes. All the obtained complexes have been studied by X-ray crystallography. Photophysical properties of the complexes have been investigated by optical spectroscopy, and all complexes exhibit luminescence in the near-infrared (Nd) and visible (Tb) regions. The total quantum yield of photoluminescence for complex 4 is 50%. Complexes 5 and 8 in combination with Bu2Mg have been used in the polymerization of ethylene.