Crystal Multi‐Conformational Control Through Deformable Carbon‐Sulfur Bond for Singlet‐Triplet Emissive Tuning

Abstract

Crystal-state luminophores have been of great interest in optoelectronics for years,w hereas the excited state regulation at the crystal level is still restricted by the lacko f control ways.W er eport that the singlet-triplet emissive property can be profoundly regulated by crystal conformational distortions.E mploying fluoro-substituted tetrakis-(arylthio)benzene luminophores as prototype,w ef ound that couples of molecular conformations formed during different crystallizations.T he deformable carbon-sulphur bond essentially drove the distortion of the molecular conformation and varied the stackingm ode,t ogether with diverse non-covalent interactions,l eading to the proportional adjustment of the fluorescence and phosphorescence bands.T his intrinsic strategy was further applied for solid-state multicolor emissive conversion and mechanoluminescence,probably offering new insights for design of smart crystal luminescent materials.

Understanding the Mechanisms of White Light Emission of a Tetradentate Pt Complex in Various Surrounding Environments

“…For electroluminescence, 75% of excitons caused by electron–hole recombination reside in the triplet state, while the rest of the 25% excitons correspond to the singlet. It is desirable to consider IQE in optoelectronic devices. , Here, the values of ISC from S 1 to T 1 ( k ISC (S 1 → T 1 )) were also calculated to consider the singlet exciton utilization efficiency . As shown in Figure S4, the k ISC (S 1 → T 1 ) of the amorphous phase (1.51 × 10 11 s –1 ) would be slightly larger than that of the crystal phase (1.40 × 10 11 s –1 ); this could be interpreted as the result of the smaller gap between S 1 and T 1 in the amorphous phase.…”

Activating Room‐Temperature Phosphorescence of Organic Luminophores via External Heavy‐Atom Effect and Rigidity of Ionic Polymer Matrix**

“…[1] Compared with fluorescent materials, materials with room-temperature phosphorescence (RTP) have received special attention for their larger Stokes shift and longer lifetime. [2] These advantages promote their applications in the fields such as molecular switches, [3] organic light-emitting diodes (OLEDs), [4] anti-counterfeiting [5] and bioimaging. [6] As pure organic molecules typically emit phosphorescence only at low temperature (e.g., 77 K) and under inert conditions, [7] traditional phosphorescent materials focus on inorganic and organometallic systems, [8] which normally rely on noble metals like iridium and platinum to promote the intersystem crossing (ISC) process.…”

Activating Room-Temperature Phosphorescence of Organic Luminophores via External Heavy-Atom Effect and Rigidity of Ionic Polymer Matrix

“…Compared with fluorescent materials, materials with room-temperature phosphorescence (RTP) have received special attention for their larger Stokes shift and longer lifetime (6)(7)(8)(9)(10)(11)(12)(13). These advantages promote their applications in the fields such as molecular switches (14)(15)(16)(17)(18), organic light-emitting diodes (OLEDs) (19)(20)(21)(22)(23), anticounterfeiting (24) and bioimaging (25). As pure organic molecules typically emit phosphorescence only at low temperature (e.g., 77 K) and under inert conditions (26,27), traditional phosphorescent materials focus on inorganic and organometallic systems (28,29), which normally rely on noble metals like iridium and platinum to promote the intersystem crossing (ISC) process.…”