Six new 3d4f heterobimetallic dinuclear complexes, [(L 1) MLn(hfac) 3] [M = Cu II, Ni II; Ln = Y III, Er III, Yb III; L 1 = 4,5-bis(propylthio)tetrathiafulvalene-N,N′-phenylenebis(salicylideneimine) and hfac - = 1,1,1,5,5,5-hexafluoroacetylacetonate], and one tetranuclear complex, [(L 2)Cu(OH)Er(hfac) 3] 2 (where L 2 = 4,5-bis(propylthio)tetrathiafulvalene-N,N′- phenyleneaminosalicylideneimine), have been synthesized. All of the X-ray structures of the coordination complexes have been resolved from single-crystal diffraction. A quantitative magnetic approach has allowed one to determine the Cu-Ln ferromagnetic interaction for Gd III (1.29 cm -1) and Tb III (0.40 cm -1) and the antiferromagnetic interaction for Dy III (-0.46 cm -1) and Yb III (-2.25 cm -1), while in the case of Er III, the magnetic interactions are negligible. The UV-visible absorption properties have been studied in a chloroform solution and rationalized by DFT and TD-DFT calculations. Upon oxidation, intramolecular SOMO → LUMO (20800 cm -1) and SOMO-n → SOMO (11350 cm -1) charge transfers appear, while the HOMO → LUMO charge transfers (20750 cm -1) disappear. The reversibility of the oxidation has been confirmed by electrochemistry and absorption properties upon the addition of a reducing agent. Irradiation at the HOMO → LUMO charge-transfer energy of the dinuclear complex [(L 1)NiY(hfac) 3] induces a ligand-centered fluorescence at 14450 cm -1.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry