The design of molecular compounds that exhibit flexibility is an emerging area of research. Although a fair amount of success has been achieved in the design of plastic or elastic crystals, realizing multidimensional plastic and elastic bending remains challenging. We report herein a naphthalidenimine–boron complex that showed size‐dependent dual mechanical bending behavior whereas its parent Schiff base was brittle. Detailed crystallographic and spectroscopic analysis revealed the importance of boron in imparting the interesting mechanical properties. Furthermore, the luminescence of the molecule was turned‐on subsequent to boron complexation, thereby allowing it to be explored for multimode optical waveguide applications. Our in‐depth study of the size‐dependent plastic and elastic bending of the crystals thus provides important insights in molecular engineering and could act as a platform for the development of future smart flexible materials for optoelectronic applications.

The synthesis of water‐soluble chitosan nanocomposites incorporating BODIPY and the investigation of their photosensitization properties is reported. It was observed that the singlet oxygen generation capability of nanocomposites containing a mixture of BODIPY and iodine‐containing molecules are higher than that of the nanocomposites containing BODIPY alone. It is hypothesized that the supramolecular interactions between BODIPY and iodine‐containing molecules confined within the nanocomposites lead to the enhanced singlet oxygen generation.

Despite the recent advancements in deciphering the underpinning rules of flexibility in organic single crystals and their superior device performance due to the nearly defect-free packing, flexible organic single crystals are scarcely used in electronic devices. Single crystals that can produce multiple readouts in response to different external stimuli could be immensely useful for molecular logic operations. Here, we report the modulation in the mechanical flexibility and fluorescence of the single crystals of a pyrene-functionalized naphthalidenimine in response to multiple chemical stimuli. Crystallographic investigations revealed that subtle changes in the weak intermolecular interactions play a critical role in defining the mechanical flexibility of these crystals. Furthermore, the multistimuli responsive mechanical and luminescence properties of these single crystals were utilized for building a multiple-input, multiple-output molecular logic gate.

Salicylideneimine-boron complexes are known to exhibit interesting photophysical properties, but fine-tuning their luminescence and mechanical properties through side-chain engineering is hitherto unknown. We report two salicylideneimine-boron complexes, the self-assembly and photophysical properties of which are reliant on the side chains: an alkyl chain imparted plasticity to the single crystals, while a fluoroalkyl chain facilitated gelation. The flexible crystals of the compound containing the alkyl chain displayed optical waveguide properties, whereas the fluorous molecule was employed for white light emission and hydrophobic luminescent marker applications. Crystallography and NMR studies indicated that weak C−H•••F and B−F•••π interactions are the key in defining the distinctive self-assembly behavior of these compounds.

Organic crystals that respond to external stimuli are interesting for the design of smart materials. Here, we show that molecular engineering can transform simple naphthalidenimine–boron complexesknown for their exciting photophysical propertiesinto functional materials that exhibit thermosalience and thermal-luminescence switching. Detailed crystallographic and spectroscopic investigations revealed the role of subtle molecular parameters in deciphering charge-transfer interactions, which in turn imparted dynamic properties to the crystals. The simultaneous observation of thermally induced jumping and luminescence switching makes these crystals ideal for optoelectronic applications.