Donor and acceptor state selectivity in resonant energy transfer

Abstract

Sm₂[Pt(CN)₄]₃•18 H₂O compounds exhibit a radiationless energy transfer from linear [Pt(CN)₄]²⁻ stacks (donors) to Sm³⁺ cations (acceptors). A Sm³⁺ emission is found, resulting from the lowest excited Sm³⁺ state (⁴G₅/₂ - ⁴F₅/₂). The energy transfer is a selective process, which has been investigated by polarized emission measurements on single crystals under high pressure. As donor state we identify the lowest excited state of the stacks (mainly emitting E perpendicular c polarized light) while the relevant acceptor state is the Sm³⁺ ⁴F₃/₂ state being the second excited state.