Metal and Proton Relay-Controlled Hierarchical Multistep Switching Cascade

Fu, Heyifei; Pramanik, Susnata; Aprahamian, Ivan

doi:10.1021/jacs.3c02855

Cited by 4 publications

(2 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The majority of these photoswitches typically involve just a single reaction coordinate, such as trans–cis isomerization or electrocyclization. − These two-stage photoswitch systems have claimed considerable interest due to their remarkable ’on/off’ control capabilities as well as their capability to symbolize binary digits (0/1) for encoding circuit information . Expansion beyond binary systems necessitates the use of photoswitches capable of undergoing controlled changes across multiple potential reaction pathways. − These versatile switches could empower the creation of advanced materials upon implementing multiaddressable units, enhanced information storage, and intricate logic circuits. ,, The efficacy of these photoswitches is critically dependent on their rate of isomerization. Slow photoisomerization is unsuitable for meeting the need for a quick response.…”

Section: Introductionmentioning

confidence: 99%

Control of Photoisomerization Kinetics via Multistage Switching in Bimetallic Ru(II)–Terpyridine Complexes

Das,

Bar,

Ganguly

et al. 2024

Inorg. Chem.

View full text Add to dashboard Cite

In this study, we carried out detailed experimental and theoretical investigation on photophysical, electrochemical, and photoisomerization behaviors of a new array of luminescent binuclear Ru(II) complexes derived from a phenylene−vinylene-substituted terpyridyl ligand possessing RT lifetimes within 60.3−410.5 ns. The complexes experienced trans-to-cis isomerization in MeCN on irradiation with visible light, accompanied by significant changes in their absorption and emission spectral profiles. The reverse cis-to-trans process is also possible with the use of ultraviolet (UV) light. On conversion from trans to cis isomers, the emission intensity increases substantially, while for the reverse process, luminescence quenching occurs. Thus, "off−on" and "on−off" emission switching is facilitated upon treatment with visible and UV light alternatively. By the use of chemical oxidants (ceric ammonium nitrate and potassium permanganate) and reductants (metallic sodium) as well as light of appropriate wavelengths, multistate switching phenomena involving reversible oxidation−reduction and trans−cis isomerization have been achieved. Interestingly, the rate of this multistate photoswitching process becomes much faster compared to only two-state trans−cis isomerization of these complexes. Density functional theory (DFT) and time-dependent-DFT (TD-DFT) calculations are also performed to obtain a clear picture of the electronic environment of the complexes and also for the appropriate assignment of absorption and emission spectral bands.

show abstract

Section: Introductionmentioning

confidence: 99%

Control of Photoisomerization Kinetics via Multistage Switching in Bimetallic Ru(II)–Terpyridine Complexes

Das,

Bar,

Ganguly

et al. 2024

Inorg. Chem.

View full text Add to dashboard Cite

show abstract

“…Hence, sequential addition of multiple stimuli (e. g., acid and base) is the prime requirement for the complete operation. Moreover, isomerization induced large geometrical change, easy modularity, and bistability bring forth access to unprecedented opportunities e. g., actuation of liquid crystalline material, [26] switchable cascade of reactions, [27,28] negative feedback loops, [29] cargo delivery, [30] intermolecular communication, [31] and programmable molecular assembler, [32] etc. However, reversible switching proceeds via concomitant accumulation of salts upon subsequent addition of acid and base that results in poor cycling performance.…”

Section: Introductionmentioning

confidence: 99%

Improving Fatigue Resistance and Autonomous Switching of pH Responsive Hydrazones by Pulses of a Chemical Fuel

Maity,

Pradhan,

Das

et al. 2024

Chemistry A European J

View full text Add to dashboard Cite

The chemically triggered reversible switching of pH‐responsive hydrazones involves rotary motion‐induced configurational changes, serving as a prototype for constructing an array of molecular machines. Typically, the configurational isomerization of such switches into two distinct forms (E/Z) occurs through the alteration of the pH the medium, achieved by successive additions of acid and base stimuli. However, this process results in intermittent operation due to the concomitant accumulation of salt after each cycle, limiting switching performance to only a few cycles (5‐6). In this context, we introduce a novel strategy for the autonomous E/Z isomerization of hydrazones in acetonitrile using pulses of trichloroacetic acid as a chemical fuel. The use of this transient acid enabled reversible switching of hydrazones even after 50 cycles without causing significant fatigue. To test the broad viability of the fuel, a series of ortho/para‐substituted hydrazones were synthesized and their switching performance was investigated. The analysis of kinetic data showed a strong dependency of switching operations including the lifetime of transient state, on the electronic properties of substituents. Finally, a distinct color change from yellow to orange due to reversible switching of the para‐methoxy substituted hydrazone was employed for the creation of rewritable messages on commercially available paper.

show abstract

Hydrazone Based pH‐Responsive Configurational Molecular Rotary Switches Containing a New Conjugated π‐Electronic Framework

Shee,

Khamaru,

Banerji

2024

Eur J Org Chem

View full text Add to dashboard Cite

A pyrido‐pyrimidinone heterocycle derived pH‐activated, hydrazone based molecular switch and its switching mechanism are reported here. The introduction of a new conjugated π electronic framework (enone part in the molecule) allowed the system to undergo hydrazone‐azo tautomerization, followed by E‐Z isomerization through rotation around the partial C−N single bond. Under acidic pH, protonation took place selectively on pyrimidinone nitrogen, and that turned the molecule to the corresponding ZH+ configuration. On the other hand, addition of triethylamine in the same solution reverted the molecule back to its original E‐configuration. Extensive proton‐NMR, and detailed X‐ray crystallography coupled with UV‐vis spectroscopy were carried out to establish the switching phenomena. Theoretical DFT calculations leading to free energy diagrams, transition states, and intermediates shed light on the mechanism behind the switching phenomenon.

show abstract

Metal and Proton Relay-Controlled Hierarchical Multistep Switching Cascade

Cited by 4 publications

References 38 publications

Control of Photoisomerization Kinetics via Multistage Switching in Bimetallic Ru(II)–Terpyridine Complexes

Control of Photoisomerization Kinetics via Multistage Switching in Bimetallic Ru(II)–Terpyridine Complexes

Improving Fatigue Resistance and Autonomous Switching of pH Responsive Hydrazones by Pulses of a Chemical Fuel

Hydrazone Based pH‐Responsive Configurational Molecular Rotary Switches Containing a New Conjugated π‐Electronic Framework

Contact Info

Product

Resources

About