A series of five title complexes was investigated spectroscopically in glasses at 77 K. Absorption and emission measurements revealed that the lowest singlet charge-transfer state moves closer in energy to both the ligand triplet and the charge-transfer triplet as the basicity of the phosphine ligands increases. The result is accompanied by a change in the relative distribution of the emissions from the latter two states. As the states become closer in energy the rate of internal conversion between singlets of disparate electronic configurations becomes slower. This is a key feature of the proposed model for this optical behavior. Consequently, intersystem crossing becomes competitive with internal conversion leading to changes in the relative yields of ligand and charge-transfer phosphorescence.

Date Published: 17 May 1989
PDF: 3 pages
Proc. SPIE 1054, Fluorescence Detection III, (17 May 1989); doi: 10.1117/12.951561

Published in SPIE Proceedings Vol. 1054:
Fluorescence Detection III
E. Roland Menzel, Editor(s)