Luminescent excimers and exciplexes of PtII compounds

Self-quenching and Cross-quenching Reactions of Excited Platinum(II) Diimine Complexes

“…Transient emission measurements indicate that the excimer luminescence reaches its maximum intensity approximately 100 ns after excitation with a short laser flash, confirming the notion that the excimer is not a ground-state aggregate. Since these earliest observations, reports by Che, [8,9] Gray, [10] and Nagle and Vogler [11] have noted similar self-quenching behavior. However, it was not until 1999 that Eisenberg and coworkers [12] established that selfquenching, sometimes accompanied by excimer emission, is a general phenomenon, apparently characteristic of all platinum(II) diimine complexes exhibiting long-lived solution emission.…”

“…[6,7,9,11,12,34] In each case, concentrated solutions give rise to a new emission band, shifted to the red of the monomer emission. At modest concentrations (10 À3 M), there is considerable evidence to support the view that this new emission band does not arise from ground-state aggregation.…”

“…[57] Excimer emission quantum yields are not available for all of the complexes listed in Table 2. Nevertheless, from the relative intensities of the monomer and excimer emissions, [6,7,9,11,34] it appears that complexes with lowest 3 (pÀp*) monomer states have higher quantum yields than those with lowest 3 MLCT monomer states. This trend could account for the fact that excimer emission has not been reported for a diimine dithiolate complex.…”

Novel near-infrared photoluminescence from platinum(II)-porphyrin (PtOEP) aggregates

“…It is widely assumed that the main characteristics of emission from excimeric states at room temperature is a broad and mostly structureless band, caused by the dissociated ground state [20,21]. The existence of triplet excimers in platinum containing organic compounds was already described [22,23].…”

Spectroscopic Studies of “Exciplex Tuning” for Dicyanoaurate(I) Ions Doped in Potassium Chloride Crystals

“…Members of this class include homoatomic and heteroatomic exciplexes involving closed shell metal ions, mostly d 8 -] and Pt 2 (P 2 O 5 H 2 ) 4-. 22 We contributed to this field by introducing the optical phenomenon of "exciplex tuning", which describes the tuning of the emission in [Ag(CN) 2 -]-doped alkali halide crystals to various bands in the ultraviolet and visible regions with each band due to a different oligomeric *[Ag(CN) 2 -] n excimer or exciplex. [23][24][25][26] Tuning the excited state properties is extremely important in a variety of optoelectronic applications in relation to some fundamental scientific issues such as excitonic energy transfer.…”