Synthesis, Time-Resolved Luminescence, NMR Spectroscopy, Circular Dichroism and Circularly Polarised Luminescence Studies of Enantiopure Macrocyclic Lanthanide Tetraamide Complexes
摘要:
The syntheses and properties of a series of lanthanide complexes (Ln = Eu, Tb, Dy, Yb) of C-4 symmetric chiral tetraamide ligands based on 1,4,7,10-tetraazacyclododecane are reported. The configuration of the chiral centre at carbon in the amide substituent (CH2NHCO-CH(Me)Ar) determines the helicity of the derived complex and the configuration of the macrocyclic ring. The enantiopure lanthanide complexes do not undergo Delta/Lambda interconversion in the temperature range 220 to 320 K and three complexes have been characterised by X-ray crystallography, revealing nine-coordination about the lanthanide ion (Ln=Eu, Dy) with a monocapped square-antiprismatic coordination geometry. The terbium complexes are highly emissive in aqueous solution following excitation into the aryl chromophore (e.g. for [Tb .(R)-7a](3+) phi H2O = 0.49; phi D2O = 0.81) and all of the lanthanide complexes exhibit strong circularly polarised luminescence. The ytterbium complexes (e.g. [Yb .(S)-5b](3+)) shows a strong near-IR CD and circularly polarised luminescence (CPL) associated with the F-2(5/2)-F-2(7/2) transition. Overall, these emissive complexes allow control in modulating both the frequency and the polarisation of emitted light in aqueous solution.
The syntheses and properties of a series of lanthanide complexes (Ln = Eu, Tb, Dy, Yb) of C-4 symmetric chiral tetraamide ligands based on 1,4,7,10-tetraazacyclododecane are reported. The configuration of the chiral centre at carbon in the amide substituent (CH2NHCO-CH(Me)Ar) determines the helicity of the derived complex and the configuration of the macrocyclic ring. The enantiopure lanthanide complexes do not undergo Delta/Lambda interconversion in the temperature range 220 to 320 K and three complexes have been characterised by X-ray crystallography, revealing nine-coordination about the lanthanide ion (Ln=Eu, Dy) with a monocapped square-antiprismatic coordination geometry. The terbium complexes are highly emissive in aqueous solution following excitation into the aryl chromophore (e.g. for [Tb .(R)-7a](3+) phi H2O = 0.49; phi D2O = 0.81) and all of the lanthanide complexes exhibit strong circularly polarised luminescence. The ytterbium complexes (e.g. [Yb .(S)-5b](3+)) shows a strong near-IR CD and circularly polarised luminescence (CPL) associated with the F-2(5/2)-F-2(7/2) transition. Overall, these emissive complexes allow control in modulating both the frequency and the polarisation of emitted light in aqueous solution.
Structural Rigidity and Luminescence of Chiral Lanthanide Tetraamide Complexes Based on 1,4,7,10-Tetraazacyclododecane
作者:Rachel S. Dickins、Judith A. K. Howard、Christian W. Lehmann、Janet Moloney、David Parker、Robert D. Peacock