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Diorganotin dihalides act as cocatalysts for site-selective and stereoselective couplings of diol-containing carbohydrates with electron-deficient alkenes in the presence of an Ir(III) photoredox catalyst and quinuclidine, a hydrogen atom transfer mediator. Quantum-chemical calculations support a proposed mechanism involving the formation of a cyclic stannylene acetal intermediate that shows enhanced reactivity toward hydrogen atom abstraction by the quinuclidinium radical cation. Addition of the carbon-centered radical to the alkene partner results in C-alkylation of the carbohydrate substrate.

Interestingly, neutral tetrathia[22]porphyrin(2.1.2.1) (TTP) acts as an efficient chemosensor for the detection of Hg2+ ions at ppb concentration. Consequent to binding the molecular plane of TTP bends and it has been supported by the DFT calculations. A rise in levelling off tail is observed in the electronic absorption spectrum in the presence of Hg2+ ions, which is suggestive of metal induced macrocyclic self-assembly and is further substantiated by the SEM, TEM and particle size measurement studies.

Herein, we have designed and synthesized new diimino dicarbazole derivative 3 which exhibits the phenomenon of aggregation induced emission enhancement (AIEE) due to the persistence of excited state intramolecular proton transfer (ESIPT) phenomenon. The aggregates of AIEE active material 3 selectively sense Cu2+ ions in nanomolar range and mediate the conversion of Cu2+ ions to Cu nanorods. The ensemble of aggregates of 3 and Cu nanorods were further utilized for selective sensing of CN¯ ions. In addition, the fluorescence behavior of the system generates the formation of molecular keypad security device. The keypad security device based on AIEE material adds to complexity of the lock and makes it more efficient.

A deep-blue-emitting sultam-based hetero[5]helicene was synthesized in four steps, and its crystal structure and physical properties were characterized. The helicene displays more than two-fold crystallization-induced emission enhancement as well as atypical blue-shifting of its solid-state emission relative to the solution phase. This rapid synthesis of an unusual sulfonamide-based helicene fluorophore is expected to generate new molecular design options that will help address the ongoing challenges associated with designing pure-blue emitters for organic optoelectronic and sensing applications.

New, neutral, slightly puckered aromatic meso-substituted tetrathia[22]porphyrin[2.1.2.1] (TTP) macrocyclic architectures display structure dependent p-type semiconductor behaviour and constitute molecular field effect transistors with a high on/off ratio (1 × 106) and high mobility (0.32 cm2 V−1 s−1) in thin films deposited on octadecyltrichlorosilane (OTS) modified SiO2. In order to study the influence of steric bulk, molecules with an increasing steric bulk at the meso-position have been synthesized and studied both experimentally and theoretically. The charge transport behavior was evaluated from their thin film organic field-effect transistor (OFET) devices. Single crystal analysis and thin film morphologies of the molecules showed that incorporating a branched hydrocarbon group at the meso-phenyl substituents of TTP not only alters face to face stacking patterns but also changes the morphology of the thin films from highly crystalline to amorphous, as well as lowering the solubility in organic solvents. Such features lead to deterioration of the performance of the organic semiconductor (OSC) devices.

New, neutral, meso-substituted tetraoxa[22]annulene[2,1,2,1] aromatic macrocycles are synthesised and disclosed as new p-type semiconductors with reproducible bulk-like carrier mobility (as high as 0.40 cm(2) V(-1) s(-1)) on highly crystalline thin films deposited on octadecyltrichlorosilane modified SiO(2).

New, neutral, slightly puckered aromatic meso-substituted tetrathia[22]annulene[2.1.2.1] macrocyclic architectures display p-type semiconductor behaviour and constitute molecular field-effect transistors with high on/off ratios (8.67 × 10(6)) and high mobility (0.23 cm(2) V(-1) s(-1)) in thin films deposited on octadecyltrichlorosilane (OTS) modified SiO(2).

New, neutral, meso-substituted aromatic annulenes (III) are synthesized via a two-step procedure starting from dialdehydes (I).

Tetrathia[22]annulene[2,1,2,1] and its derivatives are p-type organic semiconductors possessing relatively high mobilities in thin film field-effect transistors. To get a full understanding of the relationship between the molecular structures and transporting properties of these macrocyclic molecules, the single crystal structures of three meso-substituted tetrathia[22]annulene[2,1,2,1]s were determined by X-ray diffraction, and the electrical properties were investigated by single crystal transistor characterization and quantum simulations. The observed relationship between the mobilities of different crystals was strongly corroborated by calculations of both the molecular reorganization energies and the maximum intermolecular transfer integrals.