Electronic circular dichroism in the 4f–4f transitions of a series of cesium tetrakis (+)-3-heptafluorobutyrylcamphorate Ln(iii) complexes

Abstract

For electronic circular dichroism in the 4f–4f transitions (4f–4f CD) of a series of nine tetrakis ((+)-3-heptafluorobutyrylcamphorato) Ln^III complexes, Δ-SAPR-8-C₄(llll) Cs[Ln((+)-hfbc)₄]·H₂O (Cs–Ln = Cs–Pr, –Nd, –Sm, –Eu, –Dy, –Ho, –Er, –Tm, –Yb), the spectroscopic observables such as the dissymmetry factor g = Δε/ε values with the intensities (Δε) of the CD components and the molar absorption intensities (ε) in the 4f–4f transitions between the ^2S+1L_J levels are compared with each other to test the classification of the CD components in the relative order of the observables predicted in terms of the selection rule for 4f–4f transitions. The 4f–4f CD-based chiroptical spectra-structural relationship across the series of Δ-SAPR-8-C₄(llll) lanthanide(III) complexes is proposed: the signs of the 4f–4f CD or CPL in the hypersensitive transitions are related to the absolute configuration; Ln complexes with a negative CD component have the Δ-configuration around Ln^III and vice versa.