Dithienylethene‐Based Gated Ambichromic Dyads

Sanguinet, Lionel; Delbaere, Stéphanie; Berthet, Jérôme; Szalóki, György; Jardel, Damien; Pozzo, Jean‐Luc

doi:10.1002/adom.201600233

Cited by 8 publications

(11 citation statements)

References 38 publications

(36 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They can be found in Table 5 with their weighted averages as a function of the relative electronic energies, enthalpies, and Gibbs free energies (highlighting thermal and entropic effects) as well as the experimental values. 24,51 Concerning the methyl protons of both compounds under state I, the antiparallel (parallel) conformers are characterized by H 7 having a chemical shift smaller (higher) than 2.0 ppm and by H 8 being always below the same 2.0 ppm limit, with the exception of conformer h of 2 for which the H 7 and H 8 behaviors are reversed. Under state I, the most deshielded shifts are observed for H 7 in the parallel conformers at around 2.4 and 2.7 ppm for compounds 1 and 2, respectively.…”

Section: Methodsmentioning

confidence: 99%

“…Concerning the studied BOX/DTE hybrids, the opening/ closure of the oxazolidine ring induces a strong modification of the 1 H NMR spectrum facilitating the complete identification and quantification of the generated species. 24 The strong variation of the acceptor ability of BOX during its opening leads to an important deshielding of the different nuclei chemical shifts hiding a potential effect of conformational change on it. As a consequence, the increase of the chemical shifts of methyl protons (nuclei 7, Scheme 1) of the thienyl group bearing the R substituent with the BOX opening is until now the only element suggesting a variation of the parallel and antiparallel conformer ratio.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Assessing the Structure of Octastate Molecular Switches Using ¹H NMR Density Functional Theory Calculations

et al. 2018

Self Cite

View full text Add to dashboard Cite

Density functional theory calculations are used to reveal the relationships between the structures, energies, and NMR signatures of an octastate molecular switch composed of a dithienylethene (DTE) unit covalently linked to an indolino[2,1-b]oxazolidine (BOX) moiety through an ethylenic junction. Both the DTE and BOX moieties can adopt open or closed forms. The ethylenic junction can be Z or E, but the latter has been confirmed to be, by far, more stable than the former for all BOX/DTE combinations. In addition, when the DTE is open, the two thienyl units can fold to form parallel conformers, by opposition to the antiparallel or unfolded conformers. Usually parallel conformers present a higher energy than the antiparallel ones, but in the case of compound 2 having a bulky substituent (R = pPh-SMe) on the terminal thienyl group, the enthalpy of one conformer is very close (1–2 kJ mol–1) to that of the most stable antiparallel one, making photocyclization less efficient. These conformational differences and the presence of parallel DTE forms have been substantiated by analyzing experimental 1H NMR chemical shifts in light of their calculated values. These 1H NMR chemical shift calculations led to the following statements: (i) Going from state I (DTE open, BOX closed) to state II (both DTE and BOX are open) the H8 proton of compound 1 (R = Me) is deshielded by ∼0.15 ppm. (ii) The deshielding of H8 proton of compound 2 is larger and attains 0.41 ppm whereas H7 is more shielded by 0.11 ppm. (iii) Then, going from compound 1 to compound 2 leads to deshielding of both H7 and H8 protons. As a consequence, the difference of photochromism gating efficiency among compounds 1, 2, and 3 (R = pPh-OMe) can be attributed to the stabilization of parallel conformer due to an establishment of an intramolecular interaction with BOX opening.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Assessing the Structure of Octastate Molecular Switches Using ¹H NMR Density Functional Theory Calculations

et al. 2018

Self Cite

View full text Add to dashboard Cite

show abstract

“…In addition to light of different wavelengths, various external stimuli, including intramolecular hydrogen bonds, [ 156 ] multiphotonic excitation, [ 48,49 ] acid/base changes, [ 157 ] oxidation/reduction, [ 127,158 ] chemical reactions, [ 159 ] temperature changes, [ 145 ] electrochemical changes, [ 160 ] and chemical species such as ions, [ 121b,134,161 ] can also be used as input signals to change the output state or gating properties of a gate control switch containing DAE, with the changes usually reflected by a significant shift in color. Additional stimulus‐responsive units can be used to covalently modify DAE cores, [ 9c,160 ] introduce more responsive sites that allow modification in DAE‐gated switches, and design supramolecular assembly systems. [ 27,162 ] All those strategies can increase the richness of the DAE structure and function and expand its scope of application.…”

Section: Changes In the Physical And Chemical Properties Of Daementioning

confidence: 99%

Future‐Oriented Advanced Diarylethene Photoswitches: From Molecular Design to Spontaneous Assembly Systems

et al. 2022

View full text Add to dashboard Cite

cycloreversion of DAE under light irradiation produces many exciting functional effects, such as changes in photophysical and photochemical properties, [12] changes in the shape or mechanical properties of the solid, [13] electrical conductivity, [7b,14] and the generation of reactive oxygen species (ROS). [15] This type of photochromic compound can be considered a stilbene derivative. At this time, the most widely known and systematically studied DAE derivative structure contains two aryl groups and a benzene ring (usually two identical or different thiophene units with low aromatic stabilization energy [16] ) and a five-membered ring of perfluorocyclopentene and cyclopentene units [17] where the ethene bridge is located, which significantly improve photochromism. [18] In essence, the DAE photoisomerization process is a reversible electrocyclic reaction of the central 6π-electron systems. [2] Under light irradiation, DAE can rapidly and reversibly transform between its open and closed forms, and that transformation is accompanied by a color change caused by a change in the π-conjugation distribution. [2] The important thing is that the colorless opened-and colored closed-ring isomers are both thermally stable; that is, cyclization and cycloreversion do not proceed spontaneously in the dark; they need to be driven by external light irradiation at specific wavelengths. [2,19] Compared with classic lightresponsive molecules such as azobenzene, [20] the light intensity required to drive the isomerization of DAE is relatively low. Moreover, even after multiple cycles, the photochromic performance does not show significant fatigue in either the solution or solid state. [2,18b,21] DAE research to this point can be roughly divided into three stages in chronological order: early exploration of DAE's molecular structure and theory, nearly two decades of purpose-oriented molecular structure modification research, and about ten years of research into practical applications of DAE in assembly systems. Research before about 2000 focused mainly on developing more abundant DAE-derivative structures and advancing the systematic understanding of DAE's physical and chemical properties and switching performance. To regulate its switching performance and give it new functionality, many strategies for modifying the ethene bridge and aryl groups of DAE have been proposed. [22] In the first two research stages, the mechanisms and structural modification of DAE isomerization were thoroughly and systematically explored, and countless important Diarylethene (DAE) photoswitch is a new and promising family of photochromic molecules and has shown superior performance as a smart trigger in stimulus-responsive materials. During the past few decades, the DAE family has achieved a leap from simple molecules to functional molecules and developed toward validity as a universal switching building block. In recent years, the introduction of DAE into an assembly system has been an attractive strategy that enables the photochromic behavior of the b...

show abstract

“…Absorption band is bathochromically shifted to 442 nm (443 nm) with a concomitant decrease of the band at 280 nm, translating the extension of the π conjugated system and the establishment of a charge transfer band between thienyl donor and indoleninium acceptor parts , the stability of this last one is limited in our experimental conditions. Indeed, while similar compounds associating the DAE unit with one BOX unit showed no thermal evolution [18][19]…”

Section: Investigations Of Processes Between All-trans Isomers Of Tarmentioning

confidence: 99%

“…In resume, the different evidenced interconversions between the all-trans states are displayed in Scheme 2. Investigations of processes between cis isomers of targets Based on previous investigations on similar molecular system[18,19], the photo-isomerization of the ethylenic junction between BOX and DAE is expected, especially when the pending BOX is open. In this context, the trans-cis isomerization of both ethylenic junctions has been studied by 1 H NMR spectroscopy.…”

mentioning

confidence: 99%

13 metastable states arising from a simple multifunctional unimolecular system

et al. 2017

Self Cite

View full text Add to dashboard Cite

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

show abstract

Dithienylethene‐Based Gated Ambichromic Dyads

Cited by 8 publications

References 38 publications

Assessing the Structure of Octastate Molecular Switches Using ¹H NMR Density Functional Theory Calculations

Assessing the Structure of Octastate Molecular Switches Using ¹H NMR Density Functional Theory Calculations

Future‐Oriented Advanced Diarylethene Photoswitches: From Molecular Design to Spontaneous Assembly Systems

13 metastable states arising from a simple multifunctional unimolecular system

Contact Info

Product

Resources

About

Dithienylethene‐Based Gated Ambichromic Dyads

Cited by 8 publications

References 38 publications

Assessing the Structure of Octastate Molecular Switches Using 1H NMR Density Functional Theory Calculations

Assessing the Structure of Octastate Molecular Switches Using 1H NMR Density Functional Theory Calculations

Future‐Oriented Advanced Diarylethene Photoswitches: From Molecular Design to Spontaneous Assembly Systems

13 metastable states arising from a simple multifunctional unimolecular system

Contact Info

Product

Resources

About

Assessing the Structure of Octastate Molecular Switches Using ¹H NMR Density Functional Theory Calculations

Assessing the Structure of Octastate Molecular Switches Using ¹H NMR Density Functional Theory Calculations