Photo-induced modulation of electronic conductance has been achieved by employing an Ag I -based two-dimensional coordination polymer (CP) having pyridine-functionalized photochromic dimethyldihydropyrene−cyclophanediene (DHP-CPD) πswitch. Both the coordination polymer and the organic photochromic core were characterized by single-crystal X-ray diffraction studies. The coordination polymer displayed an excellent conductance in the ON state of the switch in the closed form of DHP. Upon exposure to visible light, the π-switch in the CPD form loses its planarity, turning the switch OFF, which is reflected in the drastic reduction of the conductance. Exposure to UV light turns the switch back ON wherein the high electronic conductance of the polymer can be restored.

Metal ions often influence the photoswitching efficiency of ap hotochromic system.T his article reports ao nedimensional polymer having cyclic azobenzenes coordinated to silver ions that are bridged by nitrates. The coordination polymer (CP-2)d isplays ap hotoresponsive behavior.T he switching ability in the polymer form was faster compared to the parenta zobenzene ligand withoutt he metal ions. Azobenzenes are reported to be poorlyc onducting. Here, although the azobenzene ligand does not show significant electronic mobility,t he coordination polymer (CP-2)d isplays am odest conductivity.T he conductance in the cis form of the polymer is significantly higher compared to the trans form. Upon exposure to visible light, the cis form undergoes photoisomerization to the trans form with ad rastic drop in the electronic mobility.T he trans form can be reverted to the cis form thermally or by using UV light.Thus,t his system offers ar eversible control of the conductivity using light.

Molecular switches have been used as delivery vehicles for various molecular and ionic species. The ones that reversibly operate with light are arguably the best candidates for the purpose as they can be operated using light. The two states of these photoswitchable systems often possess remarkable differences in terms of their structural features and electronic properties. Photochromic systems with the appropriate embellishment of functionalities at suitable positions have thus been used as photoresponsive receptors. The use of light-driven alterations of the structural features has led to differential molecular recognition with these switchable host molecules. In this article, we discuss the use of such supramolecular systems as the delivery vehicles for ions and molecules that started with the pioneering work by Shinkai back in 1979. This review will explicitly cover the development from 2001 to 2022 with some past background and the future prospects of the field.

The use of light as an external stimulus to control organic supramolecular structures can play an important role in molecular devices. Photoswitchable azobenzenes are well suited for such applications due to their photoresponsive properties and a thermally induced reversal from the cis to the thermodynamically stable trans state. In this work, we have demonstrated for the first time that an azobenzene-based tetraphenylethylene (TPE) system capable of aggregation-induced emission (AIE) behavior can act as a molecular glue that can noncovalently functionalize multiwalled carbon nanotubes (MWCNTs). The resulting photoresponsive, noncovalent hybrid material shows reversible conductivity switching upon irradiation with light by making use of the reversible cis–trans isomerization.

Photoinduced aggregation-disaggregation behaviour of a tetraphenylethene (TPE)-based molecule has been reversibly achieved upon photoisomerization of a photochromic dihydropyrene (DHP)-conjugated TPE derivative. The DHP-TPE conjugate forms planar stacks because of its...