Here we report the synthesis and characterization of a BF(2)-azo complex that can be induced to isomerize without need deleterious UV light. The complexation azo group with BF(2), coupled extended conjugation N═N π-electrons, increases energy n-π* transitions introduces new π-nonbonding (π(nb)) π* dominate visible region. well separated π(nb)-π* trans cis isomers enable efficient switching system by using only also leads slow → thermal relaxation rate (t(1/2) = 12.5 h). Theoretical...

In this paper we elaborate on recently developed molecular switch architectures and how these new systems can help with the realization of functions advancement artificial machines. Progress in chemically photoinduced switches motors is summarized contextualized such that reader may gain an appreciation for novel tools have come about past decade. Many offer distinct advantages over commonly employed switches, including improved fidelity, addressability, robustness. Thus, serves as a...

Increasing the electron density in BF2-coodinated azo compounds through para-substitution leads to a bathochromic shift their activation wavelength. When substituent is dimethyl amine, or like, trans/cis isomerization process can be efficiently modulated using near infrared light. The donating capability of also controls hydrolysis half-life switch aqueous solution, which drastically longer for cis isomer, while BF2-coodination prevents reduction by glutathione.

Interfacing molecular photoswitches with liquid crystal polymers enables the amplification of their nanoscale motion into macroscopic shape transformations. Typically, mechanism responsible for actuation involves light-induced disorder. Here, we demonstrate that bistable hydrazones can drive (chiral) transformations in polymer networks, photogenerated shapes displaying a long-term stability mirrors switches. The photoinduced buildup tension polymer, negligible influence on crystalline order....

A new family of BF2–hydrazone complexes was developed that exhibit enhanced emission in the solid-state. The modularity systems enabled their structure–property analysis, which showed solid-state fluorescence quantum yield is dependent on molecule's planarity, dipole moment and number π–π interactions it forms. One easily transformed into a acid/base sensor.

Two intramolecularly hydrogen-bonded arylhydrazone (aryl = phenyl or naphthyl) molecular switches have been synthesized, and their full reversible switching between the E Z configurations demonstrated. These chemically controlled configurational rotary exist primarily as isomer at equilibrium can be switched to protonated configuration (Z-H(+)) by addition of trifluoroacetic acid. The protonation pyridine moiety in switch induces a rotation around hydrazone C=N double bond, leading...

Entering a new phase: Mesogenic stoppers (purple) at the ends of rod section switchable donor–acceptor [2]rotaxane induce formation smectic A liquid-crystalline (LC) phase over wide temperature range. The bistable which contains tetracationic cyclophane (blue), tetrathiafulvalene unit (green), and 1,5-dioxynaphthalene (red) self-assembles into LC with layer spacing about 8 nm (see picture).

ConspectusThe ability to selectively and effectively control various molecular processes via specific stimuli is a hallmark of the complexity biological systems. The development synthetic structures that can mimic such processes, even on fundamental level, one main goals supramolecular chemistry. Having this in mind, there has been foray research past two decades aimed at developing architectures, whose properties be modulated using external inputs. In most cases, reversible conformational,...

A family of easily accessible light-activated hydrazone switches has been developed having thermal half-lives up to 2700 years! Structure-property analysis shows that replacing the rotor pyridyl group our typical switch with a phenyl one leads long-lived negative photochromic compounds. The switching properties hydrazones in both toluene and DMSO were assessed offering insights into kinetics thermodynamics process.

Among the growing collection of molecular systems under consideration for nanoscale device applications, mechanically interlocked compounds derived from electrochemically switchable bistable [2]rotaxanes and [2]catenanes show great promise. These demonstrate dynamic, relative movements between their components, such as shuttling circumrotation, enabling them to serve stimuli-responsive switches operated via reversible, electrochemical oxidation−reduction rather than through addition chemical...

The replacement of one the carbonyl groups in a 1,2,3-triketone-2-naphthylhydrazone with pyridine ring yields an original molecular switch that can be switched fully, effectively, and reversibly between E Z configurations. This hydrazone-based, pH-controlled, is first example chemically controlled configurational rotary switch. bistable exists primarily (97%) as configuration solution converted quantitatively to Z-H+ upon treatment trifluoroacetic acid. When passed over plug K2CO3,...

This feature article surveys the various ways by which a structurally simple hydrazone can be used in accessing different functional materials, mainly photo/chemically activated switches, fluorophores and sensors.

Molecular switches and machines that are powered by acid-base reactions susceptible to low switching cycles because of the concomitant formation waste products during their operation. Here, we demonstrate fast, efficient, reversible modulation a hydrazone switch in methanol using visible-light activated photoacid, with no generation side products, high conversion rates (>95%), loss activity over 100 cycles. TEG functionalization allows for process be carried (>90%) water as well.

The development of new photochromic compounds and the optimization their photophysical switching properties are prerequisites for accessing functions opportunities that not possible with currently available systems. To this end we recently developed a bistable hydrazone switch undergoes efficient photoswitching emission ON/OFF toggling in both solution solid-state. Here, present systematic structure-property analysis using family hydrazones show how properties, including activation...

The dynamic manipulation of the properties soft matter can lead to adaptive functional materials that be used in advanced applications. Here we report on a new chiral dopant, built an isosorbide scaffold attached two bistable hydrazone-based light switches control self-assembly, and hence photophysical properties, nematic liquid crystals (LCs). bistability switch allows kinetic trapping various helical assemblies as function photostationary states, resulting reflection different wavelengths...

The generally small Gibbs free energy difference between the Z and E isomers of hydrazone photoswitches has so far precluded their use in photon storing applications. Here, we report on a series cyclic acyclic hydrazones, which possess varied degrees ring strain and, hence, stability isomers. photoinduced isomerization concurrent phase transition hydrazones from crystalline to liquid result storage large quantity energy, comparable that azobenzene derivatives. We demonstrate macrocyclic...

Adaptive materials that exhibit a multichromatic response as function of applied stimulus are highly desirable, they can result in applications ranging from smart surfaces to anticounterfeit devices. Here we report on such system based an intriguing thermal 1,2-BF2 shift transforms visible-light-activated azo-BF2 photoswitch into BF2-hydrazone fluorophore (BODIHY) both solution and the solid-state. Structure–property analysis, conjunction with DFT calculations, reveals is catalyzed by...

Pumping ions against a concentration gradient through protein-based transporters is cornerstone of numerous biological processes. Mimicking this function by using artificial receptors remains daunting challenge, mainly because the difficulties in balancing between requirement for high binding affinities and precise on-demand ion capture release properties. We report trimeric hydrazone photoswitch-based receptor that converts light energy into work actively transporting chloride anion...