Structural and photophysical studies on geometric (Er_2Yb _2/Yb_2Er_2) and configurational (EuTb _3/Eu_3Tb) isomers of heterotetranuclear lanthanide(III) complexes

摘要

Heterotetranuclear geometrical (Er_2Yb_2/Yb _2Er_2) and configuational (EuTb_3/Eu _3Tb) isomeric lanthanide(III) complexes have been synthesized and characterized by spectroscopy as well as X-ray crystallography. The geometric Er_2Yb_2/Yb_2Er_2 isomers exhibit dual emissions from both erbium(III) and ytterbium(III) ions. For the EuTb _3/Eu_3Tb configurational isomers, the Tb~(III) subunits transfer energy to the Eu~(III) centers in the EuTb_3 complex, whereas the Tb~(III) ion in the TbEu_3 complex serves mainly as a structural stabilizer.