Excitation wavelength dependent (Ex-De) emission materials have potential applications in anti-counterfeiting labels and bioimaging.N evertheless,f ew purely organic chromophores are used in these areas.I nt his study,m ultiple excited states were incorporated into am olecule that was excited state intramolecular proton transfer (ESIPT) active, with the goal of manipulating the relaxation pathwayso ft he excited states.T he triazole derivative exhibits Ex-De photoluminescence (PL), and the maximum PL wavelength is located at 526 nm and 593 nm under as eries of excitation wavelengths.S pectral identification indicates that the excimer and ESIPT processes are responsible for the green (526 nm) and orange (593 nm) fluorescence,r espectively.I mportantly, the quickr esponse code and test strip prepared with this triazole derivative can be used for anti-counterfeiting and food spoilage detection applications,r espectively.T his research opens the door for developing novel Ex-De materials for anti-counterfeiting purposes.The luminescence behavior of most fluorescent molecules follows Kashasr ule,t hat is,t he photoluminescence (PL) wavelength is independent of the excitation wavelength. Exceptions to Kashasrule arise when large energy gaps exist between excited states because of the suppression of the internal conversion (IC) process. [1] Excitation wavelength dependent (Ex-De) emission materials are highly desirable for use in biological labels,a nti-counterfeiting applications [5] and various optoelectronic devices. [2] At ypical Ex-De mol-ecule is azulene,w hich has been widely studied since the 1960s. [1c, 3] However,itisessentially useless because of the low PL efficiencya nd poor color difference.R ecent focus of Ex-De materials has been on nanoparticles (nanocrystals and carbon/silica dots) and metal complexes. [4] Forthe former, the emission wavelength can be shifted by using size control (or size distribution), element doping, and surface states.Surface functional groups,s uch as CÀN/CÀOa nd/or CÀN, can efficiently introduce new energy levels for electron transitions and lead to the Ex-De phenomenon. [4a-c] Fort he latter, incorporating metal ions into an organic ligand, which generally facilitates intersystem crossing from the singlet to triplet states,r esulted in phosphorescence and prompt fluorescence. [4e, 5] Purely organic materials that have the advantages of excellent processability,w ide variety,g ood biocompatibility,a nd appreciable stability are attractive alternatives.U nfortunately,m ost of the purely organic materials exhibit af ast IC process from S 2 to S 1 ,e specially in the aggregated state,a nd as ar esult, the Ex-De fluorescence behavior is rarely observed. Moreover,t heir potential application, especially in anti-counterfeiting applications,has not been well demonstrated.Thetriazole compound BH-BA(Scheme 1), which has the trade name "deferasirox", is aknown commercial drug for the treatment of transfusional chronic iron overload. [6] Interestingly,w ef ind that this purely organic m...

Sulfur, which is generated from the waste byproducts in the oil and gas refinery industry, is an abundant, cheap, stable, and readily available source in the world. However, the utilization of excessive amounts of sulfur is mostly limited, and developing novel methods for sulfur conversion is still a global concern. Here, we report a facile one-step conversion from elemental sulfur to functional poly(O-thiocarbamate)s through a multicomponent polymerization of sulfur, diols, and diisocyanides, which possesses a series of advantages such as mild condition (55 °C), short reaction time (1 h), 100% atom economy, and transition-metal free in the catalyst system. Seven poly(O-thiocarbamate)s are constructed with high yields (up to 95%), large molecular weight (up to 53100 of M w ), good solubility in organic solvents, and completely new polymer structures. The poly(O-thiocarbamate)s possess a high refractive index above 1.7 from 600 to 1700 nm by adjusting the sulfur content. By incorporating tetraphenylethene (TPE) moieties into the polymer structure, the poly(O-thiocarbamate)s can also be designed as fluorescent sensors to detect harmful metal cation of Hg 2+ in a turn-on mode with high sensitivity (LOD = 32 nM) and excellent selectivity (over interference cations of Pb 2+ , Au 3+ , Ag + ). Different from the previous reports, the exact coordination structure is first identified by single-crystal X-ray diffraction, which is revealed in a tetracoordination fashion (two sulfur and two chloride) using a model coordination compound.

A NIR light induced H2S release platform based on UCNPs was constructed. Under NIR light excitation, UCNPs can emit UV light which triggers H2S release in a spatial and temporal pattern. The platform was also employed to real-time monitor the delivery process in vivo, which may provide a new way for the use of H2S-based therapeutics for a variety of diseases.

Tetraphenylethylene (TPE) and its derivatives are the typical aggregation-induced emission (AIE) compounds with helical chirality, and they have enormous applications potential in chiral sensor, asymmetric catalyst, optoelectronic materials, and so on. The aggregation-induced helical chirality of TPE and its derivatives can only be observed in condensed phase such as crystalline or film state. The accurate determination of absolute configuration (AC) of TPE core compounds is complicated and difficult, especially when there is no heavy atoms exist in their structures. Herein, we demonstrate a powerful and convenient method to quickly determine the helical chirality of these stereochemically labile TPE core compounds through the combination of comprehensive solid-state chiroptical spectroscopy and theoretical calculation. Our study reveals that from lower to higher energy of the fingerprint region, the first electronic circular dichroism (ECD) band in the 300−450 nm or the first most intensive vibrational circular dichroism (VCD) peak in the 875−730 cm −1 can be used as the diagnostic bands for the AC determination of the TPE core with the fixed chirality. If these diagnostic bands cannot be observed in ECD or VCD spectra, the helical chirality of the atropisomers of TPE derivatives is not fixed. The explicit AC determination of TPE core contributes to the study of the helical chirality of supramolecular TPE core derivatives and allows for the further fabrication of novel chiral AIE functional materials.

Azabenzanthrone derivatives with high phototoxicity and efficient emission are designed for photodynamic therapy and deep-tissue imaging.