Conservation laws, radiative decay rates, and excited state localization in organometallic complexes with strong spin-orbit coupling

摘要: There is longstanding fundamental interest in 6-fold coordinated $d^6$ ($t_{2g}^6$) transition metal complexes such as [Ru(bpy)$_3$]$^{2+}$ and Ir(ppy)$_3$, particularly their phosphorescence. This has increased with the growing realisation that many of these have potential uses applications including photovoltaics, imaging, sensing, light-emitting diodes. In order to design new properties tailored for specific a detailed understanding low-energy excited states, lowest energy triplet state, $T_1$, required. Here we describe model pseudo-octahedral based on pseudo-angular momentum representation show predictions this are excellent agreement experiment - even when deviations from octahedral symmetry large. gives natural explanation zero-field splitting $T_1$ relative radiative rates three sublevels terms conservation time-reversal parity total angular modulo two. We broad parameter regime consistent experimental data implies significant localization state.