scholarly journals Stimuli Responsive Materials Supported by Orthogonal Hydrogen and Halogen Bonding or I···Alkene Interaction

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7586
Author(s):  
Pierre Frangville ◽  
Shiv Kumar ◽  
Michel Gelbcke ◽  
Kristof Van Van Hecke ◽  
Franck Meyer
Keyword(s):  
Smart Materials ◽  
Color Change ◽  
Uv Light ◽  
Halogen Bond ◽  
Halogen Bonding ◽  
Building Blocks ◽  
Stimuli Responsive ◽  
Compound I ◽  
Ph Variation ◽  
Responsive Materials

Smart materials represent an elegant class of (macro)-molecules endowed with the ability to react to chemical/physical changes in the environment. Herein, we prepared new photo responsive azobenzenes possessing halogen bond donor groups. The X-ray structures of two molecules highlight supramolecular organizations governed by unusual noncovalent bonds. In azo dye I-azo-NO2, the nitro group is engaged in orthogonal H···O···I halogen and hydrogen bonding, linking the units in parallel undulating chains. As far as compound I-azo-NH-MMA is concerned, a non-centrosymmetric pattern is formed due to a very rare I···π interaction involving the alkene group supplemented by hydrogen bonds. The Cambridge Structural Database contains only four structures showing the same I···CH2=C contact. For all compounds, an 19F-NMR spectroscopic analysis confirms the formation of halogen bonds in solution through a recognition process with chloride anion, and the reversible photo-responsiveness is demonstrated upon exposing a solution to UV light irradiation. Finally, the intermediate I–azo–NH2 also shows a pronounced color change due to pH variation. These azobenzenes are thereby attractive building blocks to design future multi-stimuli responsive materials for highly functional devices.

scholarly journals Multi Stimuli Responsive Materials Supported by Orthogonal Hydrogen and Halogen Bonding or I···Alkene Interaction

2021 ◽  
Author(s):  
Pierre Frangville ◽  
Shiv Kumar ◽  
Michel Gelbcke ◽  
Kristof Van Hecke ◽  
Franck Meyer
Keyword(s):  
Smart Materials ◽  
Color Change ◽  
Uv Light ◽  
Halogen Bond ◽  
Halogen Bonding ◽  
Building Blocks ◽  
Stimuli Responsive ◽  
Ph Variation ◽  
Responsive Materials ◽  
Noncovalent Bonds

Smart materials represent an elegant class of (macro)-molecules endowed with the ability to react to chemical/physical changes in the environment. Herein, we prepared new photo responsive azobenzenes possessing halogen bond donor groups. The X-ray structures of two molecules highlight supramolecular organizations governed by unusual noncovalent bonds. In azo dye I-azo-NO2, the nitro group is engaged in orthogonal H···O···I halogen and hydrogen bonding, linking the units in parallel undulating chains. As concern parent I-azo-NH-MMA, a non-centrosymmetric pattern is formed due to a very rare I···π interaction involving the alkene group supplemented by hydrogen bonds. The Cambridge Structural Database contains only four structures with the same I···CH2=C contact. For all compounds, a 19F NMR spectroscopic analysis confirms the formation of halogen bonds in solution through a recognition process with chloride anion, and the reversible photo-responsiveness is demonstrated upon exposing a solution to UV light irradiation. Finally, intermediate I-azo-NO2 also shows a pronounced color change due to pH variation. These azobenzenes are thereby attractive building blocks to design multi-stimuli responsive materials for highly functional devices.

scholarly journals Concomitant Photoresponsive Chiroptics and Magnetism in Metal-Organic Frameworks at Room Temperature

Research ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Bin Xia ◽  
Qian Gao ◽  
Zhen-Peng Hu ◽  
Qing-Lun Wang ◽  
Xue-Wei Cao ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Smart Materials ◽  
Room Temperature ◽  
Color Change ◽  
Metal Organic Frameworks ◽  
Stimuli Responsive ◽  
Responsive Materials ◽  
Chiral Carbon ◽  
Cotton Effects ◽  
Metal Organic

Stimulus-responsive metal-organic frameworks (MOFs) can be used for designing smart materials. Herein, we report a family of rationally designed MOFs which exhibit photoresponsive chiroptical and magnetic properties at room temperature. In this design, two specific nonphotochromic ligands are selected to construct enantiomeric MOFs, {Cu2(L-mal)2(bpy)2(H2O)·3H2O}n (1) and {Cu2(D-mal)2(bpy)2(H2O)·3H2O}n (2) (mal=malate, bpy=4,4’−bipyridine), which can alter their color, magnetism, and chiroptics concurrently in response to light. Upon UV or visible light irradiation, long-lived bpy− radicals are generated via photoinduced electron transfer (PET) from oxygen atoms of carboxylates and hydroxyl of malates to bpy ligands, giving rise to a 23.7% increase of magnetic susceptibility at room temperature. The participation of the chromophores (-OH and -COO−) bound with the chiral carbon during the electron transfer process results in a small dipolar transition; thus, the Cotton effects of the enantiomers are weakened along with a photoinduced color change. This work demonstrates that the simultaneous responses of chirality, optics, and magnetism can be achieved in a single compound at room temperature and may open up a new pathway for designing chiral stimuli-responsive materials.

scholarly journals Contrasting Photo-Switching Rates in Azobenzene Derivatives: How the Nature of the Substituent Plays a Role

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1019
Author(s):  
Domenico Pirone ◽  
Nuno A. G. Bandeira ◽  
Bartosz Tylkowski ◽  
Emily Boswell ◽  
Regine Labeque ◽  
...  
Keyword(s):  
Visible Light ◽  
Smart Materials ◽  
Density Functional ◽  
Molecular Design ◽  
Visible Region ◽  
Building Blocks ◽  
Stimuli Responsive ◽  
Order Of Magnitude ◽  
Azo Derivatives ◽  
Commercial Polymers

A molecular design approach was used to create asymmetrical visible light-triggered azo-derivatives that can be good candidates for polymer functionalization. The specific electron–donor substituted molecules were characterized and studied by means of NMR analyses and UV-visible spectroscopy, comparing the results with Time Dependent Density Functional (TD-DFT) calculations. A slow rate of isomerization (ki = 1.5 × 10−4 s−1) was discovered for 4-((2-hydroxy-5methylphenyl) diazenyl)-3-methoxybenzoic acid (AZO1). By methylating this moiety, it was possible to unlock the isomerization mechanism for the second molecule, methyl 3-methoxy-4-((2-methoxy-5-methylphenyl) diazenyl)benzoate (AZO2), reaching promising isomerization rates with visible light irradiation in different solvents. It was discovered that this rate was heightened by one order of magnitude (ki = 3.1 × 10−3 s−1) for AZO2. A computational analysis using density functional (DFT/PBE0) and wavefunction (QD-NEVPT2) methodologies provided insight into the photodynamics of these systems. Both molecules require excitation to the second (S2) excited state situated in the visible region to initiate the isomerization. Two classic mechanisms were considered, namely rotation and inversion, with the former being energetically more favorable. These azo-derivatives show potential that paves the way for future applications as building blocks of functional polymers. Likewise, they could be really effective for the modification of existing commercial polymers, thus transferring their stimuli responsive properties to polymeric bulky structures, converting them into smart materials.

scholarly journals Stimuli-Responsive Materials for Tissue Engineering and Drug Delivery

2020 ◽  
Vol 21 (13) ◽  
pp. 4724 ◽  
Author(s):  
Sofia Municoy ◽  
María I. Álvarez Echazú ◽  
Pablo E. Antezana ◽  
Juan M. Galdopórpora ◽  
Christian Olivetti ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Smart Materials ◽  
Controlled Drug Release ◽  
Stimuli Responsive ◽  
Responsive Materials ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers ◽  
Stimuli Response ◽  
Materials Used

Smart or stimuli-responsive materials are an emerging class of materials used for tissue engineering and drug delivery. A variety of stimuli (including temperature, pH, redox-state, light, and magnet fields) are being investigated for their potential to change a material’s properties, interactions, structure, and/or dimensions. The specificity of stimuli response, and ability to respond to endogenous cues inherently present in living systems provide possibilities to develop novel tissue engineering and drug delivery strategies (for example materials composed of stimuli responsive polymers that self-assemble or undergo phase transitions or morphology transformations). Herein, smart materials as controlled drug release vehicles for tissue engineering are described, highlighting their potential for the delivery of precise quantities of drugs at specific locations and times promoting the controlled repair or remodeling of tissues.

Synergistic effects of halogen bond and π–π interactions in thiophene-based building blocks

RSC Advances ◽  
2015 ◽  
Vol 5 (100) ◽  
pp. 82544-82548 ◽  
Author(s):  
Jamey Wilson ◽  
Jon Steven Dal Williams ◽  
Chesney Petkovsek ◽  
Peyton Reves ◽  
Jonah W. Jurss ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Computational Chemistry ◽  
Building Block ◽  
Halogen Bond ◽  
Synergistic Effects ◽  
Supramolecular Assembly ◽  
Halogen Bonding ◽  
Building Blocks ◽  
X Ray ◽  
X Ray Crystallography

The use of a thiophene-based building block (Pyr-T) to achieve a supramolecular assembly driven by halogen bonding (XB) is described. X-ray crystallography, NMR, Raman spectroscopy, and computational chemistry afford evidence of strong XB and π–π stacking.

scholarly journals A Raman Spectroscopic and Computational Study of New Aromatic Pyrimidine-Based Halogen Bond Acceptors

Inorganics ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 119 ◽  
Author(s):  
Hardin ◽  
Ellington ◽  
Nguyen ◽  
Rheingold ◽  
Tschumper ◽  
...  
Keyword(s):  
Self Assembly ◽  
Density Functional ◽  
Computational Study ◽  
Halogen Bond ◽  
Normal Modes ◽  
Halogen Bonding ◽  
Building Blocks ◽  
Molecular Assembly ◽  
X Ray ◽  
X Ray Crystallography

Two new aromatic pyrimidine-based derivatives designed specifically for halogen bond directed self-assembly are investigated through a combination of high-resolution Raman spectroscopy, X-ray crystallography, and computational quantum chemistry. The vibrational frequencies of these new molecular building blocks, pyrimidine capped with furan (PrmF) and thiophene (PrmT), are compared to those previously assigned for pyrimidine (Prm). The modifications affect only a select few of the normal modes of Prm, most noticeably its signature ring breathing mode, ν1. Structural analyses afforded by X-ray crystallography, and computed interaction energies from density functional theory computations indicate that, although weak hydrogen bonding (C–H···O or C–H···N interactions) is present in these pyrimidine-based solid-state co-crystals, halogen bonding and π-stacking interactions play more dominant roles in driving their molecular-assembly.

scholarly journals Bacillus spores as building blocks for stimuli-responsive materials and nanogenerators

2014 ◽  
Vol 9 (2) ◽  
pp. 137-141 ◽  
Author(s):  
Xi Chen ◽  
L. Mahadevan ◽  
Adam Driks ◽  
Ozgur Sahin
Keyword(s):  
Building Blocks ◽  
Stimuli Responsive ◽  
Responsive Materials ◽  
Bacillus Spores

scholarly journals Cobaloximes as Building Blocks in Halogen-Bonded Cocrystals

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2370
Author(s):  
Nikola Bedeković ◽  
Valentina Martinez ◽  
Edi Topić ◽  
Vladimir Stilinović ◽  
Dominik Cinčić
Keyword(s):  
Single Crystal ◽  
Halogen Bond ◽  
Halogen Bonding ◽  
Building Blocks ◽  
X Ray Diffraction ◽  
X Ray ◽  
Organic Halogen ◽  
Metal Organic

In this work, we explore the halogen-bonded cocrystallization potential of cobaloxime complexes in the synthesis of cocrystals with perhalogenated benzenes. We demonstrate a strategy for synthesizing halogen-bonded metal–organic cocrystals by utilizing cobaloximes whose pendant bromide group and oxime oxygen enable halogen bonding. By combining three well-known halogen bond donor molecules differing in binding geometry and composition with three cobaloxime units, we obtained a total of four previously unreported cocrystals. Single crystal X-ray diffraction experiments showed that the majority of obtained cocrystals exhibited the formation of the targeted I···O and I···Br motives. These results illustrate the potential of cobaloximes as halogen bond acceptors and indicate that this type of halogen bond acceptors may offer a novel route to metal–organic halogen-bonded cocrystals.

scholarly journals Exploring the Halogen-Bonded Cocrystallization Potential of a Metal-Organic Unit Derived from Copper(ii) Chloride and 4-Aminoacetophenone

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2385
Author(s):  
Vinko Nemec ◽  
Katarina Lisac ◽  
Marin Liović ◽  
Ivana Brekalo ◽  
Dominik Cinčić
Keyword(s):  
Hydrogen Bonding ◽  
Halogen Bond ◽  
Halogen Bonding ◽  
Building Blocks ◽  
Supramolecular Interactions ◽  
X Ray Diffraction ◽  
Square Planar ◽  
Metal Organic ◽  
Acetyl Group ◽  
Conventional Solution

In this work, we describe a novel halogen-bonded metal-organic cocrystal involving a square-planar Cu(ii) complex and 1,4-diiodotetrafluorobenzene (14tfib) by utilizing an amine ligand whose pendant acetyl group enables halogen bonding. The cocrystal was prepared by both mechanochemical synthesis (liquid-assisted grinding) and the conventional solution-based method. Crystal structure determination by single crystal X-ray diffraction revealed that the dominant supramolecular interactions are the I···O halogen bond between 14tfib and CuCl2(aap)2 building blocks, and the N–H···Cl hydrogen bonds between CuCl2(aap)2 molecules. The combination of halogen and hydrogen bonding leads to the formation of a 2D network. Overall, this work showcases an example of the possibility for extending the complexity of metal-organic crystal structures by using halogen bonding in a way that does not affect other hydrogen bonding synthons.

scholarly journals Performing calculus: Asymmetric adaptive stimuli-responsive material for derivative control

2021 ◽  
Vol 7 (14) ◽  
pp. eabe5698
Author(s):  
Spandhana Gonuguntla ◽  
Wei Chun Lim ◽  
Fong Yew Leong ◽  
Chi Kit Ao ◽  
Changhui Liu ◽  
...  
Keyword(s):  
Smart Materials ◽  
Self Regulation ◽  
Fast Response ◽  
Stimuli Responsive ◽  
Mathematical Operation ◽  
Responsive Materials ◽  
Analytical Functions ◽  
Temporal Derivative ◽  
Impermeable Layer ◽  
Designed Materials

Materials (e.g., brick or wood) are generally perceived as unintelligent. Even the highly researched “smart” materials are only capable of extremely primitive analytical functions (e.g., simple logical operations). Here, a material is shown to have the ability to perform (i.e., without a computer), an advanced mathematical operation in calculus: the temporal derivative. It consists of a stimuli-responsive material coated asymmetrically with an adaptive impermeable layer. Its ability to analyze the derivative is shown by experiments, numerical modeling, and theory (i.e., scaling between derivative and response). This class of freestanding stimuli-responsive materials is demonstrated to serve effectively as a derivative controller for controlled delivery and self-regulation. Its fast response realizes the same designed functionality and efficiency as complex industrial derivative controllers widely used in manufacturing. These results illustrate the possibility to associate specifically designed materials directly with higher concepts of mathematics for the development of “intelligent” material-based systems.

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