The intramolecular charge transfer-driven emission properties of T and V-shaped donor-acceptor-donor molecules involving a new acceptor core of pyridoquinoxaline were demonstrated. The T-shaped molecule exhibits a large Stokes shift, red emission in the solid state and remarkable viscosity and temperature-dependent tunable fluorescence including a thermally-induced single-component near white-light emission.

White light emitting (WLE) materials are of increasing interesto wing to their promising applicationsi na rtificial lighting, display devices, molecular sensors, and switches.I n this context,o rganic WLE materials cater to the interesto f the scientific community owing to their promising features like color purity,l ong-term stability,s olutionp rocessability, cost-effectiveness,a nd low toxicity.T he typical methodf or the generation of white light is to combine three primary (red, green, and blue) or the two complementary (e.g., yellow and blue or red and cyan) emissive units covering the whole visible spectralw indow (400-800 nm). The judicious choice of molecular buildingb locks and connecting them through either strong covalentb onds or assembling through weakn oncovalent interactions are the key to achieve enhanced emissions panning the entire visible region.In the present review article, moleculare ngineering approaches for the development of all-organic WLE materials are analyzed in view of different photophysical processes like fluorescencer esonance energy transfer (FRET), excitedstate intramolecular protont ransfer (ESIPT), charget ransfer (CT), monomer-excimer emission, triplet-state harvesting, etc. The key aspect of tuning the molecular fluorescence under the influence of pH, heat, and host-guest interactions is also discussed. The white light emission obtained from small organic molecules to supramolecular assemblies is presented,i ncluding polymers, micelles,a nd also employing covalent organic frameworks. The state-of-the-art knowledge in the field of organic WLE materials, challenges, and future scope are delineated.

Tailoring the formation of dynamic and static excimers in a C3-symmetric architecture led to efficient generation of white light and sensitive detection of Fe3+ and Al3+ in a single molecular platform.

Macrocyclic cavitands having aesthetically appealing architectures and excellent host−guest complexation abilities exhibit a broad range of applications from molecular separation, catalysis, and sensing to drug delivery. However, the close packing of the zero-dimensional (0D) porous cavitands reduces their activity in the solid state. Knitting the macrocyclic cavitands using suitable aromatic linkers may lead to a new generation of porous organic polymers (POPs) where the intrinsic properties of the cavitands can be augmented through interconnected pores in the solid state. Herein, we demonstrate the design strategy of linking the 0D-discrete pores by connecting Cphenylresorcin[4]arene (RN4) through three different aromatic linkers. The flexible azo linkers generate highly dispersible hierarchically mesoporous POP (RN4-Az-OH) exhibiting a remarkable catalytic activity toward metal-free cycloaddition of CO 2 with epoxides under solvent-free reaction conditions. Alkyne-based rigid linkers lead to microporous polymer (RN4-OH), which shows CO 2 and H 2 uptake at low pressure. The fluorine-rich linkers produce ultramicroporous hydrophobic POP (RN4-F) exhibiting high efficiency toward the charge-specific size-selective removal of organic micropollutants from water. Resorcin[4]arene-derived POPs show superior performance compared to the pristine 0D-porous building units. Thus, "connecting the dots" (0D pores) gives rise to a new interface between supramolecular chemistry and porous organic materials, which can be explored further to address the challenging problems related to green energy and environmental remediation.

A versatile fluorescent probe, PITE, based on alkyl-substituted pyridoindole (PI) and tetraphenylethylene (TE), which exhibits facile pH-induced fluorescence switching in solution, as nanoparticles, and in the solid state, is presented. Strong fluorescence in the solid state, as well as in solution and the aggregated state, allow sensing of toxic acid vapors. Fluorescence "off-on" switching of PITE through exposure to trifluoroacetic acid and triethylamine vapor is visualized by the naked eye. A unified picture of the switchable fluorescence of PITE is obtained by comprehensive spectroscopic investigations coupled with quantum mechanical calculations. Strong fluorescence, a large Stokes shift, high photostability, and biocompatibility of PITE make it a viable probe for subcellular imaging. Extensive fluorescence microscopic studies by employing organisms including lower and higher eukaryotes reveal specific localization of PITE to lipid droplets (LDs). LDs are dynamic subcellular organelles linked to various physiological processes and human diseases. Hence, the specific detection of LDs in diverse organisms is important to biomedical research and healthcare. Isolation of LDs and subsequent colocalization studies ascertain selective targeting of LDs by the easily affordable, lipophilic bioprobe, PITE. Thus, PITE is a promising multifunctional probe for chemosensing and the selective tracking of LDs.