Intercluster aurophilicity-driven aggregation lighting circularly polarized luminescence of chiral gold clusters

Herein,we prepared two novel pairs of enantiomeric gold cluster complexes,AU4PL4/Au4PD4 and(Au4L4)n/(Au4D4)n with atomic precision.In Au4PL4/Au4PD4,the discrete chiral Au4-based aggregation-induced emission(AIE)luminogens are separated by bulky substitutes.The corresponding aggregates are cyan-emitting with a photoluminescence quantum yield(PLQY)of 14.4%.Upon decreasing the size of the substituents,these chiral Au4 clusters are strung together by inter-cluster Au-Au interactions,which cause a low-energy green emission from the aggregated(Au4L4)n/(Au4D4)n with a much higher PLQY of 41.4%and more intense circularly polarised photoluminescence(CPL)with a dissymmetry factor|gPL|of 7.0×10^−3.Using(Au4L4)n/(Au4D4)n,circularly polarised organic light-emitting diodes(CP-OLEDs)were for the first time fabricated with|gEL|=|gPL|.These findings signify that inter-cluster metallophilic interactions are a new and important type of driving force for AIE and crystallization-induced emission(CIE),suggesting great potential of CPL-active metal clusters in CP-OLEDs.

Metallophilicity-Induced Clusterization:Single-Component White-Light Clusteroluminescence with Stimulus Response

Materials showing metallophilic interactions continue to attract considerable theoretical and experimental attention largely because of their unusual and unanticipated photophysical behavior as well as their unique stimuli-responsive behavior in an aggregate or solid state.Metallophilic interactions are mostly found between metals with either identical(d^(10)–d^(10))or different(s^(2)–d^(8),d^(8)–d^(10))configurations.Among various metallophilic interactions,aurophilic interactions(Au⋯Au)are well-known and widely reported.In this study,a new phosphorescent gold(I)complex,[(CF_(3)Ph)_(3)PAuC≡CPh](TPPGPA)was reported.

Aggregation-induced phosphorescence and mechanochromic luminescence of a tetraphenylethene-based gold(Ⅰ) isocyanide complex

In this study,a new twisting gold（Ⅰ） isocyanide complex based on tetraphenylethene（TPE）,TPE-NC-Au.was designed and synthesized.It exhibits aggregation induced phosphorescence（AIP） characteristics,owing to the incorporation of Au moiety and conformation rigidification in the aggregated states.Moreover,the emission color of the crystalline solid of TPE-NC-Au changes from blue（454 nm） to green（500 nm） in response to mechanical grinding,due to the combined effects of conformation planarization,enhanced π…π stacking,as well as the emergence of aurophilic interactions in the ground amorphous state.Notably,the emission color can be restored upon solvent fuming,associating with the reconstruction of crystalline lattices.The AIP and switchable mechanochromism of TPE-NC-Au make it suitable for potential applications in bioimaging,sensing,and optoelectronic devices.

Progress in mechanochromic luminescence of gold(Ⅰ) complexes

Photophysical properties of organic and organometallic luminophors are closely related with their molecular packings, enabling the exploitation of stimuli-responsive functional luminescent molecules.Mechanochromic molecules, which can change their luminescence characteristics after mechanical stimulus, have received an increasing interest due to their promising applications in multifunctional sensors and molecular switches. During the past two decades, the development of gold(Ⅰ) chemistry has been attracting the attention of plenty of researchers. Indeed, a variety of gold(I) complexes with fascinating photophysical behaviors have been discovered. This review focuses on the research progress in the different types of mechanoluminochromic gold(Ⅰ) complexes, including mono-, bi-and multi-nuclear gold(Ⅰ)systems. Their interesting luminescence behaviors of these gold(Ⅰ)-containing luminogens upon mechanical stimulus and the proposed mechanisms of their observed mechanochromic luminescence are summarized systematacially. Moreover, this review will put forward an outlook about the possible opportunities and challenges in this significative scientific field.

Aggregation-enhanced direct S_(0)-T_(n) transitions and room-temperature phosphorescence in gold(I)-complex single crystals

The design of efficient aggregation-induced emission materials requires an improved understanding of photophysical processes in aggregated materials.Herein,the photophysical behavior of an Au(I)complex(R6)that exhibits intense roomtemperature phosphorescence(RTP)in crystals is described.In addition,the photophysical processes related to RTP are discussed based on the structure of the molecular aggregates and the primary structure of the molecule.An extremely efficient S_(0)-T_(n) direct transition is found to occur in the R6 crystal.Furthermore,intermolecular Au-Au interactions and the internal/external heavy-atom effects of Au atoms are demonstrated to enhance the electronic transitions involving intersystem crossing,namely,direct S_(0)-T_(n) excitation,radiative T_(1)-S_(0) transition(phosphorescence),and S_(1)-T_(n) intersystem crossing.Because of the dense molecular packing,both Au-Au interactions and heavy-atom effects play important roles in the crystals.As a result,R6 shows more efficient RTP in crystals than in solution.These insights into the mechanism of highly efficient RTP in Au(I)-complex crystals are expected to advance the development of new luminogens for a variety of sensing and imaging applications.