The conjugate base of methyl 3-oxobutanoate as an antenna ligand in visible-emitting photoluminescent lanthanide complexes†
Coordination compounds with the formulae [Y(MAA)3]x (1Y), [Ln(MAA)3]x (1Ln), [Y(MAA)3(phen)] (2Y) and [Ln(MAA)3(phen)] (2Ln) (Ln = Sm, Eu, Tb, Dy, Yb; MAA = conjugate base of methyl 3-oxo-butanoate; phen = 1,10-phenantroline) were synthesized and characterized, and X-ray diffraction data were collected for [Tb(MAA)3(phen)] (2Tb) and [Yb(MAA)3(phen)] (2Yb). Most of the lanthanide derivatives showed appreciable luminescence in the solid state upon excitation with near-UV light. Strong emissions were observed in particular for complexes of lanthanide ions with high-energy resonance levels. Visible-emitting [Ln(MAA)3(phen)] compounds were successfully used as dopants for the preparation of luminescent poly(methylmethacrylate) samples. Similar derivatives of the conjugate base of dimethyl malonate (DMM), with formulae [Y(DMM)3(phen)] (3Y) and [Ln(DMM)3(phen)] (3Ln) (Ln = Eu, Tb, Dy), were also synthesized and their photoluminescence behaviour was compared to that of the analogous methyl 3-oxo-butanoato-complexes.