Circularly polarized luminescence of terbium (III) complexes in solution

✍ Scribed by Chun Ka Luk; F.S. Richardson

• Publisher: Elsevier Science
• Year: 1974
• Tongue: English
• Weight: 591 KB
• Volume: 25
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(74)89121-9

✦ Synopsis

Circular dichroism (CD). total luminescence, and circularly polarized luminescence (CPL) spectra of Tb(II1) : malic acid and Th(III) : aspartic acid complexes are measured in aqueous solution at room temperature. The CD is measured in the spectral region corresponding to the Tb(II1) 'Fd -'D4 free-ion absorption, and the CPL spectra span the Tb(IIIj 'Da -7F6, 7FS. 7F4, and 7Fa free-ion emissions. All solutions included in the study were at pH = 8.5 and had ligand : Tb(III) concentration ratios of 5: l_ Experiments were conducted using the d. Q. and racemic (d. Q) optical isomers of the ligands. Whereas the total luminescence spectra associated with the individual 'Da -7F~ transitions are unstructured or show, at most, two components, the CPL spectra are highly structured and demonstrate considerable splitting of the Jlevels by the lowsymmetry l&and environment. Furthermore, CPL exhibits an extraordinary sensitivity to the chemical or stereochemical nature of the ligand environment as evidenced by the different sign patterns and splittings revealed in the CPL spectra of the malic acid and aspartic acid complexes.