A mechanochromic donor-acceptor torsional spring

AbstractMechanochromic polymers are intriguing materials that allow to sense force of specimens under load. Most mechanochromic systems rely on covalent bond scission and hence are two-state systems with optically distinct “on” and “off” states where correlating force with wavelength is usually not possible. Translating force of different magnitude with gradually different wavelength of absorption or emission would open up new possibilities to map and understand force distributions in polymeric materials. Here, we present a mechanochromic donor-acceptor (DA) torsional spring that undergoes force-induced planarization during uniaxial elongation leading to red-shifted absorption and emission spectra. The DA spring is based on ortho-substituted diketopyrrolopyrrole (o-DPP). Covalent incorporation of o-DPP into a rigid yet ductile polyphenylene matrix allows to transduce sufficiently large stress to the DA spring. The mechanically induced deflection from equilibrium geometry of the DA spring is theoretically predicted, in agreement with experiments, and is fully reversible upon stress release.

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Spectral fine tuning of cyanine dyes: electron donor–acceptor substituted analogues of thiazole orange

Photochemical & Photobiological Sciences ◽

10.1039/c5pp00117j ◽

2015 ◽

Vol 14 (9) ◽

pp. 1703-1712 ◽

Cited By ~ 11

Author(s):

Elizabeth E. Rastede ◽

Matteus Tanha ◽

David Yaron ◽

Simon C. Watkins ◽

Alan S. Waggoner ◽

...

Keyword(s):

Electron Donor ◽

Emission Spectra ◽

Fine Tuning ◽

Cyanine Dye ◽

Thiazole Orange ◽

Absorption And Emission ◽

Donor And Acceptor ◽

Dye Absorption ◽

Donor Acceptor ◽

Electron Donor And Acceptor

Strategically placed electron donor and acceptor groups allow fine-tuning of cyanine dye absorption and emission spectra while preserving recognition of biomolecular hosts such as DNA and proteins.

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Near infra-red dyes based on pyrene aza-BODIPYs

New Journal of Chemistry ◽

10.1039/c7nj03408c ◽

2018 ◽

Vol 42 (8) ◽

pp. 5875-5888 ◽

Cited By ~ 7

Author(s):

Naresh Balsukuri ◽

Nayan Jyoti Boruah ◽

Praseetha E. Kesavan ◽

Iti Gupta

Keyword(s):

Energy Transfer ◽

Emission Spectra ◽

Efficient Energy Transfer ◽

Absorption And Emission ◽

Efficient Energy ◽

Absorption And Emission Spectra ◽

Infra Red ◽

Donor Acceptor

Donor–acceptor type pyrene substituted aza-BODIPYs are reported, and efficient energy transfer from pyrene moieties to the aza-BODIPY core caused significant red shifts in their absorption and emission spectra.

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Theoretical Study of the Substituent and Solvent Effects on the Molecular Structures, Absorption and Emission Spectra of Open-Form Spiropyrans

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20040047 ◽

2004 ◽

Vol 69 (1) ◽

pp. 47-62 ◽

Cited By ~ 2

Author(s):

Yinghong Sheng ◽

Jerzy Leszczynski

Keyword(s):

Solvent Effects ◽

Emission Spectra ◽

Molecular Structures ◽

Open Form ◽

Geometrical Parameters ◽

Excitation Energies ◽

Absorption And Emission ◽

Absorption And Emission Spectra ◽

Donor Acceptor ◽

The Impact

The effects of substituents and solvents on the molecular structures, excitation energies and emission energies of a series of donor-acceptor substituted spiropyrans were investigated using the density functional methods. Different donor-acceptor pairs lead to alternations of the molecular structures. A relationship between the strengths of donor-acceptor pairs and the structural parameter BLA (bond length alternation) was examined and discussed. The impact on geometrical parameters induced by the solvents is more significant than that caused by the substituents, as indicated by the larger BLA changes. The substituent and solvent effects on the UV absorption and emission spectra of open-form spiropyrans were studied by the TD-DFT method. The absorption maxima of open-form spiropyrans are expected to red shift, and the emission are expected to blue shift as the strengths of donor-acceptor pairs and the polarities of solvents increase. A simple model was adopted to mimic the substituent and solvent effects, in the framework of AM1, employing Sparkles to create an external electric field on the open-form spiropyran, in order to induce a systematical polarization of the molecular equilibrium geometry and the electronic configuration.

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Backbone Effects on the Thermoelectric Properties of Ultra-Small Bandgap Conjugated Polymers

Polymers ◽

10.3390/polym13152486 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2486

Author(s):

Dexun Xie ◽

Jing Xiao ◽

Quanwei Li ◽

Tongchao Liu ◽

Jinjia Xu ◽

...

Keyword(s):

Conjugated Polymers ◽

Power Factor ◽

Carrier Mobility ◽

Polymeric Materials ◽

Thermoelectric Performance ◽

Organic Thermoelectric Materials ◽

Higher Power ◽

Donor Acceptor ◽

Maximum Power Factor ◽

Higher Carrier Mobility

Conjugated polymers with narrower bandgaps usually induce higher carrier mobility, which is vital for the improved thermoelectric performance of polymeric materials. Herein, two indacenodithiophene (IDT) based donor–acceptor (D-A) conjugated polymers (PIDT-BBT and PIDTT-BBT) were designed and synthesized, both of which exhibited low-bandgaps. PIDTT-BBT showed a more planar backbone and carrier mobility that was two orders of magnitude higher (2.74 × 10−2 cm2V−1s−1) than that of PIDT-BBT (4.52 × 10−4 cm2V−1s−1). Both exhibited excellent thermoelectric performance after doping with 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane, where PIDTT-BBT exhibited a larger conductivity (0.181 S cm−1) and a higher power factor (1.861 μW m−1 K−2) due to its higher carrier mobility. The maximum power factor of PIDTT-BBT reached 4.04 μW m−1 K−2 at 382 K. It is believed that conjugated polymers with a low bandgap are promising in the field of organic thermoelectric materials.

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Aromaticity and photophysics of tetrasila- and tetragerma-annelated tetrathienylenes as new representatives of the hetero[8]circulene family

Physical Chemistry Chemical Physics ◽

10.1039/c9cp01608b ◽

2019 ◽

Vol 21 (18) ◽

pp. 9246-9254 ◽

Cited By ~ 11

Author(s):

G. V. Baryshnikov ◽

R. R. Valiev ◽

V. N. Cherepanov ◽

N. N. Karaush-Karmazin ◽

V. A. Minaeva ◽

...

Keyword(s):

Electronic Structure ◽

Emission Spectra ◽

Absorption And Emission ◽

Absorption And Emission Spectra ◽

Photophysical Behavior

The electronic structure, absorption and emission spectra, aromaticity and photophysical behavior of the recently synthesized tetrasilatetrathia[8]circulene and tetragermatetrathia[8]circulene compounds have been studied computationally.

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