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