scholarly journals Template-Free Synthesis of a Phenanthroline-Containing [2]Rotaxane: A Reversible pH-Controllable Molecular Switch

Symmetry ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1137
Author(s):  
Muraoka ◽  
Aoyama ◽  
Fujihara ◽  
Yamane ◽  
Hisaki ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Molecular Switches ◽  
Molecular Switch ◽  
Molecular Sensors ◽  
Template Free

The synthesis of symmetric and asymmetric rotaxanes consisting of neutral axle and ring components without ionic templates is necessary for applications in molecular sensors and molecular switches. A phenanthroline-containing symmetric [2]rotaxane was newly synthesized by inducing hydrogen bonding and π-interaction using a template-free threading-followed-by-stoppering method. The obtained rotaxane serves as a reversible pH-controllable molecular switch.

scholarly journals Phycocyanobilin in solution – a solvent triggered molecular switch

2014 ◽  
Vol 16 (13) ◽  
pp. 6146-6152 ◽  
Author(s):  
Tobias Watermann ◽  
Hossam Elgabarty ◽  
Daniel Sebastiani
Keyword(s):  
Hydrogen Bonding ◽  
Molecular Switch ◽  
Conformational Switching ◽  
Spectroscopic Behaviour ◽  
Hydrogen Bonding Pattern

The chromophore phycocyanobilin changes its spectroscopic behaviour upon solvent change. Our calculations trace this effect back to conformational switching, induced by changes in the hydrogen bonding pattern.

Remote conformational control of a molecular switch via methylation and deprotonation

2014 ◽  
Vol 12 (46) ◽  
pp. 9384-9388 ◽  
Author(s):  
Peter C. Knipe ◽  
Ian M. Jones ◽  
Sam Thompson ◽  
Andrew D. Hamilton
Keyword(s):  
Hydrogen Bonding ◽  
Conformational Changes ◽  
Molecular Switch ◽  
Conformational Control ◽  
Remote Sites ◽  
Hydrogen Bonding Network

Methylation and deprotonation at remote sites of a diphenylacetylene-based molecular switch exert global conformational changes through subtle tuning of a hydrogen-bonding network.

scholarly journals Analog Signalling with ‘Digital’ Molecular Switches

2018 ◽  
Author(s):  
Stephen E Clarke
Keyword(s):  
Synaptic Plasticity ◽  
Experimental Evidence ◽  
Stable State ◽  
Molecular Switches ◽  
Molecular Switch ◽  
Analog Signal ◽  
Input Frequency ◽  
Stable States ◽  
Short Timescale ◽  
Long Timescales

AbstractMolecular switches, such as the protein kinase CaMKII, play a fundamental role in cell signalling by decoding inputs into either high or low states of activity; because the high activation state can be turned on and persist after the input ceases, these switches have earned a reputation as ‘digital’. Although this on/off, binary perspective has been valuable for understanding long timescale synaptic plasticity, accumulating experimental evidence suggests that the CaMKII switch can also control plasticity on short timescales. To investigate this idea further, a non-autonomous, nonlinear ordinary differential equation, representative of a general bistable molecular switch, is analyzed. The results suggest that switch activity in regions surrounding either the high- or low-stable states of activation could act as a reliable analog signal, whose short timescale fluctuations relative to equilibrium track instantaneous input frequency. The model makes intriguing predictions and is validated against previous work demonstrating its suitability as a minimal representation of switch dynamics; in combination with existing experimental evidence, the theory suggests a multiplexed encoding of instantaneous frequency information over short timescales, with integration of total activity over long timescales.Author SummaryBistable molecular switches can decode cellular inputs into distinct high- or low-states of persistent enzymatic activity. Although this on-off, ‘digital’ perspective is valuable for long timescales, I suggest that short timescale fluctuations of switch activity around either stable state acts as an analog signal that reliably encodes instantaneous input frequency. A minimal model and theory make predictions about the molecular switch CaMKII, synaptic plasticity and burst detection.

Solvatochromic, thermochromic and pH-sensory DCDHF-hydrazone molecular switch: response to alkaline analytes

RSC Advances ◽  
2016 ◽  
Vol 6 (104) ◽  
pp. 102296-102305 ◽  
Author(s):  
Tawfik A. Khattab ◽  
Brylee David B. Tiu ◽  
Sonya Adas ◽  
Scott D. Bunge ◽  
Rigoberto C. Advincula
Keyword(s):  
Molecular Switches ◽  
Molecular Switch ◽  
Stimuli Responsive

Nanostructures fabricated from multi-stimuli responsive DCDHF-hydrazone molecular switches to function as colorimetric reversible gas probes.

Synergistic regulation of nonbinary molecular switches by protonation and light

2021 ◽  
Vol 118 (47) ◽  
pp. e2112973118
Author(s):  
Xin Zhang ◽  
Yu-Dong Yang ◽  
Zhi-Hao Lu ◽  
Li-Jin Xu ◽  
Jonathan L. Sessler ◽  
...  
Keyword(s):  
Dicarboxylic Acid ◽  
Hierarchical Control ◽  
Functional Materials ◽  
Molecular Switches ◽  
Molecular Switch ◽  
Molecular Devices ◽  
Control Factor ◽  
Molecular Switching ◽  
Stimulus Responsive ◽  
Synergistic Regulation

We report a molecular switching ensemble whose states may be regulated in synergistic fashion by both protonation and photoirradiation. This allows hierarchical control in both a kinetic and thermodynamic sense. These pseudorotaxane-based molecular devices exploit the so-called Texas-sized molecular box (cyclo[2]-(2,6-di(1H-imidazol-1-yl)pyridine)[2](1,4-dimethylenebenzene); 14+, studied as its tetrakis-PF6− salt) as the wheel component. Anions of azobenzene-4,4′-dicarboxylic acid (2H+•2) or 4,4′-stilbenedicarboxylic acid (2H+•3) serve as the threading rod elements. The various forms of 2 and 3 (neutral, monoprotonated, and diprotonated) interact differently with 14+, as do the photoinduced cis or trans forms of these classic photoactive guests. The net result is a multimodal molecular switch that can be regulated in synergistic fashion through protonation/deprotonation and photoirradiation. The degree of guest protonation is the dominating control factor, with light acting as a secondary regulatory stimulus. The present dual input strategy provides a complement to more traditional orthogonal stimulus-based approaches to molecular switching and allows for the creation of nonbinary stimulus-responsive functional materials.

De novo design approach based on nanorecognition toward development of functional molecules/materials and nanosensors/nanodevices

2007 ◽  
Vol 79 (6) ◽  
pp. 1057-1075 ◽  
Author(s):  
N. Jiten Singh ◽  
Han Myoung Lee ◽  
Seung Bum Suh ◽  
Kwang S. Kim
Keyword(s):  
Hydrogen Bonding ◽  
Conformational Changes ◽  
De Novo ◽  
Redox System ◽  
Molecular Switches ◽  
Interaction Forces ◽  
Π Interactions ◽  
Mechanical Devices ◽  
Organic Nanotubes ◽  
Enzyme Mimetics

For the design of functional molecules and nanodevices, it is very useful to utilize nanorecognition (which is governed mainly by interaction forces such as hydrogen bonding, ionic interaction, π-H/π-π interactions, and metallic interactions) and nanodynamics (involving capture, transport, and release of electrons, photons, or protons). The manifestation of these interaction forces has led us to the design and realization of diverse ionophores/receptors, organic nanotubes, nanowires, molecular mechanical devices, molecular switches, enzyme mimetics, protein folding/unfolding, etc. In this review, we begin with a brief discussion of the interaction forces, followed by some of our representative applications. We discuss ionophores with chemo-sensing capability for biologically important cations and anions and explain how the understanding of hydrogen bonding and π-interactions has led to the design of self-assembled nanotubes from calix[4]hydroquinone (CHQ). The binding study of neutral and cationic transition metals with the redox system of hydroquinone (HQ) and quinone (Q) predicts what kind of nanostructures would form. Finally, we look into the conformational changes between stacked and edge-to-face conformers in π-benzoquinone-benzene complexes controlled by alternating electrochemical potential. The resulting flapping motion illustrates a promising pathway toward the design of mobile nanomechanical devices.

Novel inorganic aromatic mixed-valent superalkali electride CaN3Ca: an alkaline-earth-based high-sensitivity multi-state nonlinear optical molecular switch

2020 ◽  
Vol 22 (10) ◽  
pp. 5985-5994
Author(s):  
Yin-Feng Wang ◽  
Tian Qin ◽  
Jia-Min Tang ◽  
Yan-Jiao Liu ◽  
Miao Xie ◽  
...  
Keyword(s):  
High Performance ◽  
Nonlinear Optical ◽  
Alkaline Earth ◽  
High Sensitivity ◽  
Molecular Switches ◽  
Molecular Switch ◽  
Quantum Mechanical ◽  
Mechanical Methods

Focusing on innovative high-performance single-pole double-throw nonlinear optical (NLO) molecular switches, two C3v configurations (1 and 3) and one D3h configuration (2) of bipyramidal CaN3Ca have been obtained by using quantum mechanical methods.

scholarly journals Exploring the pH-dependent kinetics, thermodynamics and photochemistry of a flavylium-based pseudorotaxane

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Rita Anastácio ◽  
André Seco ◽  
Pedro Mateus ◽  
A. Jorge Parola ◽  
Nuno Basílio
Keyword(s):  
Time Scales ◽  
Reaction Network ◽  
Molecular Switches ◽  
Molecular Switch ◽  
Stimuli Responsive ◽  
Ph Dependent ◽  
Molecular Components ◽  
Different Time Scales

Abstract Flavylium-based molecular switches are attractive molecular components to devise stimuli-responsive host-guest systems such as rotaxanes and pseudorotaxanes. These compounds display a pH-dependent reaction network of several species that reversibly interconvert within different time scales. Therefore, to explore and take profit of exceptional stimuli-responsive properties of these systems, detailed kinetic and thermodynamic characterizations are often required. In this work, we present the results of such characterization for a new flavylium compound decorated with a trimethylalkylammonium substituent designed to form a pseudorotaxane with cucurbit[7]uril (CB7). The formation of the pseudorotaxane was characterized in detail, and the thermodynamic and kinetic aspects of the flavylium interconversion reactions in the assembly were investigated and compared with the free molecular switch.

scholarly journals Supramolecular electron transfer-based switching involving pyrrolic macrocycles. A new approach to sensor development?

2015 ◽  
Vol 51 (37) ◽  
pp. 7781-7794 ◽  
Author(s):  
Nathan L. Bill ◽  
Olga Trukhina ◽  
Jonathan L. Sessler ◽  
Tomás Torres
Keyword(s):  
Electron Transfer ◽  
Energy Transfer ◽  
Molecular Switches ◽  
Potential Utility ◽  
New Approach ◽  
Molecular Sensors ◽  
Sensor Development

The potential utility of energy transfer in the design of pyrrolic macrocycle-based molecular switches and ability to serve as the readout motif for molecular sensors development is discussed.

From Electride-like Super Alkali Earth Atom to Superalkalide or Superalkali Electride: M(HF)3M (M = Na or Li) as Field-Induced Excellent Inorganic NLO Molecular Switches

2021 ◽  
Author(s):  
Yin-Feng Wang ◽  
Jia-Jun Wang ◽  
Jia Li ◽  
Xue-Xia Liu ◽  
Zhijun Wang ◽  
...  
Keyword(s):  
Molecular Electronics ◽  
Molecular Switches ◽  
Molecular Switch ◽  
Excess Electron ◽  
Alkali Earth ◽  
Electron Compounds

Exploring novel molecular switch is an ongoing hot issue in molecular electronics. Alkalide and electride are two typical representatives of excess electron compounds. It was found that M(HF)3M (M =...

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