Thiacalixarene assembled heterotrinuclear lanthanide clusters comprising Tb^III and Yb^III enable f-f communication to enhance Yb^III-centred luminescence

A mixture of heterotrinuclear lanthanide cluster complexes, Tb_3-xYb_xTCAS₂ (x = 1, 2), was obtained by mixing thiacalix[4]arene-p-tetrasulfonate (TCAS), Tb^III, and Yb^III, which shows enhanced Yb^III-centred luminescence and shortened lifetime for Tb^III-centred luminescence as compared to Yb₃TCAS₂ and Tb₃TCAS₂, indicating f-f communication, i.e., energy transfer from Tb^III to Yb^III.