Revealing High-Lying Intersystem Crossing in Brightly Luminescent Cyclic Trinuclear Cu^I/Ag^I Complexes

Abstract

The increased attention to luminescent copper(I) complexes, mostly mononuclear and dinuclear ones, in the past few years was mainly due to the new pathways established in the intersystem crossing (ISC) for highly efficient singlet/triplet harvesting, which showed great potential in light-emitting devices. Governing the photophysical processes of planar cyclic trinuclear complexes is more challenging owing to the rich intra-and intermolecular metal−metal interactions involved, but new opportunities also accompany this. Herein reported is a hidden route to the ultra-long-lived, highly efficient phosphorescence of cyclic trinuclear two-coordinate Cu I −pyrazolate complexes through pushing the unfavorable metal-to-ligand charge transfer events to the high-lying ISC pathways. Moreover, an anomaly of much higher quantum yields of a trinuclear Ag I −pyrazolate complex relative to its Cu I analogue is observed.

Variable Luminescence and Chromaticity of Homoleptic Frameworks of the Lanthanides together with Pyridylpyrazolates

“…For 3-PyPzH and 4-PyPzH, the emission maxima appear in the range of 400 to 410 nm. [15] The emission profiles of Sm 3 + 1 and 6 display the characteristic transitions 4 G 5/2 ! 6 H J , J = 5/2-13/2 for Sm 3 + with the 4 G 5/2 !…”

Pressure-induced phosphorescence enhancement and piezochromism of a carbazole-based cyclic trinuclear Cu(i) complex

“…28,36,37 Such luminescence, termed "metal-sensitized phosphorescence", is attributed to the enhanced intersystem crossing (ISC) rate from singlet excited states to triplet states mediated by external heavy-atom effect (e.g., Au, Ag, Cu and Hg). 38,39 In this way, we are proposing that the external isotropic pressure can enforce the interactions between CTCs and organic chromophores, resulting in alteration of electronic structures of emission center and triggering the PIPE. To our best of knowledge, the investigations of the luminescence behaviour of such organic chromophore-CTC adducts under high pressure have been rarely reported.…”

Syntheses, Crystal Structures and Photophysical Properties of Dinuclear Copper(I) Complexes Bearing Diphenylphosphino‐Substituted Benzimidazole Ligands

“…[29] Furthermore, density functional theory (DFT) and timedependent density functional theory (TD-DFT) computational study are performed at PBE0 level, since theoretical singlet and triplet energies based on PBE0 functional have been demonstrated to be in good agreement with the experimental results. [30] The optimized geometries of the complexes in S 1 state ( Figure S7, Table S8) adopt a structural distortion with respect to those in T 1 state ( Figure S8, Table S9), especially for 3. The calculated results are graphically visualized in Figure 6, Figure S9 and Figure S10.…”