Energy transfer from Gd3+ to Tb3+ in solution

The use of the 4f7 ion Gd3+ as an energy transfer donor in solution is reported for the first time. The luminescence from the 6P multiplet term of Gd3+ in chloride solution is quenched not only by increasing concentration, but also by the addition of Tb3+. The energy transfer from Gd3+ to Tb3+ in solution has been followed by selective decay measurements and the energy transfer constant shows a linear relationship with Tb3+ concentration up to ∼0.05 M, after which value saturation is reached. The Tb3+ acceptor 5D4 emission intensity as a function of time is well-modeled.