Cationic [Cu(P^P)(Htbz)]PF6[P^P = xantphos,
dpephos;
Htbz = 2-(4-thiazolyl)benzimidazole] and the corresponding neutral
complexes [Cu(P^P)(tbz)], obtained through deprotonation of the diimine
ligand, have been synthesized with the aim of analyzing the role of
the diphosphane and Htbz deprotonation in the emissive properties
of these complexes. For the study of the diphosphane effect, the luminescence
properties of these compounds have been compared with those of the
reported analogous derivatives with Htbz and carborane diphosphanes.
Complexes [Cu(P^P)(Htbz)]PF6(P^P = xantphos, dpephos)
and [Cu(dpephos)(tbz)] display thermally activated delayed fluorescence,
which has been studied, revealing a ΔE(S1–T1) between 658 and 455 cm–1. Theoretical calculations indicate different origins for the absorptions,
leading to the observed emissions.