MULTIPLE EMISSION FROM SULFUR COMPLEXES OF RHODIUM(III) AND IRIDIUM(III)

The preparation, purification, absorption, and emission spectra and emission lifetimes are reported forfour trisdithioketone complexes of rhodium(III) and iridium(III). The broad, structureless, red emission observed for the four complexes overlaps with the absorption spectra and can for each compound be resolved into two Gaussian components. Decay curves measured at the emission peak wavelength can be fit with a sum of two exponentials. The photoselection technique is used to verify the two-state emission from these complexes. Analysis of these data indicates that the multiple emission is an intramolecular phenomena with the two emitting states assigned as a d-d and a charge transfer (II-d*). Excitation spectra indicate the existence of independent pathways of population for the two states. Temperature-dependent lifetimes and quantum yields permit measurement of activation energies in plastic solvent media. Kinetic models are presented and decay data interpreted as indicating the presence of a finite rise time for the emission of one of the excited states. © 1979, American Chemical Society. All rights reserved.