Infrared luminescence quenching in erbium(III) tris(8-quinolinolate): an ab initio approach

We present here an ab initio calculation of the quenching rate of erbium luminescence by the ligand C-H vibrations in erbium(III) tris(8- quinolinolate) within the framework of energy- transfer theory. The C-H vibrational transition matrix elements are evaluated on the basis of DFT calculations of the quinolate ligand at the B3LYP/6-311++ G(2d, 2p) level of theory. The luminescence lifetime calculated by considering the dipole-dipole and quadrupole - dipole interaction mechanisms is in good agreement with the experimental value. Based on the theoretical results for the complex, the dependence of the luminescence quenching rates on the distance between the erbium ion and the C-H bond is generalized and discussed, and comparisons with available experimental results are made.