Abstract:

To study intermolecular energy transfer of rare earth-β-diketones, monolayers of mixed RE(TTA)3Phen (RE=La, Gd, Tb, or Y) with Eu(TTA)3Phen in molar ratio of 1:1 and 1:4 were fabricated in this paper. Meanwhile, an active enhanced sphere model was proposed to acquire the efficient radii of energy transfer between the molecules of complexes. The efficient radius for energy transfer from Gd(TTA)3Phen or Tb(TTA)3Phen to Eu(TTA)3Phen is 12Å and those from La (TTA)3Phen and Y(TTA)3Phen to Eu(TTA)3Phen are 7Å and 10Å, respectively. The reliability of the model was proved by comparing the emission intensities that were calculated by using values of R mentioned above with experimental values. The model proposed is a supplement to Perrins active sphere theory. By this model a triplet-triplct energy transfer can be deduced from TTA of RE(TTA)3Phen to that of Eu(TTA)3Phen. The process proceeds by an electron exchange mechanism.

Key words: LB films, Rare earth, Complex, Energy transfer, Active enhanced sphere