In situ monitoring of polymerredox states by resonance μRaman spectroscopy and its applications in polymer modified microfluidic channels

Logtenberg, Hella; Jellema, Laurens-Jan C.; Lopez-Martinez, Maria J.; Areephong, Jetsuda; Verpoorte, Elisabeth; Feringa, Ben L.; Browne, Wesley R.

doi:10.1039/c1ay05475a

Cited by 7 publications

(18 citation statements)

References 22 publications

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“…The spacer unit, in such systems, plays an important role in determining the overall function of the systems. Earlier studies on compounds in which a functional unit, such as a dithienylethene photochromic switch, was tethered to a pair of electrodimerizable/polymerizable units showed that the introduction of a phenyl spacer aids the polymerization process and improves the retention of the functionality of the photoswitchable moiety. − Koyuncu et al took a similar approach in which carbazole units are attached directly at their 3-position to both ends of a naphthalene diimide, enabling polymerization through sequential dimerization (Figure ). With this approach, however, only partial quenching of photoluminescence was observed, ascribed in part due to perturbation of the properties of the carbazole by direct attachment of the diimide unit to it.…”

Section: Introductionmentioning

confidence: 99%

Reversible Charge Trapping in Bis-Carbazole-Diimide Redox Polymers with Complete Luminescence Quenching Enabling Nondestructive Read-Out by Resonance Raman Spectroscopy

et al. 2017

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The coupling of substituted carbazole compounds through carbon–carbon bond formation upon one-electron oxidation is shown to be a highly versatile approach to the formation of redox polymer films. Although the polymerization of single carbazole units has been proposed earlier, we show that by tethering pairs of carbazoles double sequential dimerization allows for facile formation of redox polymer films with fine control over film thickness. We show that the design of the monomers and in particular the bridging units is key to polymer formation, with the diaminobenzene motif proving advantageous, in terms of the matching to the redox potentials of the monomer and polymer film and thereby avoiding limitations in film thickness (autoinsulation), but introduces unacceptable instability due to the intrinsic redox activity of this moiety. The use of a diimide protecting group both avoids complications due to p-diamino-benzene redox chemistry and provides for a redox polymer in which the photoluminescence of the bis-carbazole moiety can be switched reversibly (on/off) with redox control. The monomer design approach is versatile enabling facile incorporation of additional functional units, such as naphthalene. Here we show that a multicomponent carbazole/naphthalene containing monomer (APCNDI) can form redox polymer films showing both p- and n- conductivity under ambient conditions and allows access to five distinct redox states, and a complex electrochromic response covering the whole of the UV/vis–NIR spectral region. The highly effective quenching of the photoluminescence of both components in poly-APCNDI enables detailed characterization of the redox polymer films. The poly-APCNDI films show extensive charge trapping, which can be read out spectroscopically in the case of films and is characterized as kinetic rather than chemical in origin on the basis of UV/vis–NIR absorption and resonance Raman spectroscopic analyses. The strong resonantly enhanced Raman scattering for the various oxidized and reduced states of APCNDI enables nondestructive “read-out” of the state of the polymer, including that in which charges are trapped kinetically at the surface, making poly-APCNDI highly suitable for application as a component in organic nonvolatile memory devices.

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Section: Introductionmentioning

confidence: 99%

Reversible Charge Trapping in Bis-Carbazole-Diimide Redox Polymers with Complete Luminescence Quenching Enabling Nondestructive Read-Out by Resonance Raman Spectroscopy

et al. 2017

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“…23 One approach that has been taken to prevent the loss of photochromic function upon electropolymerization is to introduce a spacer unit between the photoswitchable moiety and the unit responsible for electropolymerization. 24,25 Although this approach leads to polymer films that show reversible photochemical switching, the methoxystyryl units used to form the polymer through oxidative coupling resulted in poor photostability of the film overall, especially upon irradiation with UV light. 25 In the present contribution, an alternative approach is taken to circumvent these complications by avoiding the use of a separate functional unit for electropolymerization.…”

Section: ■ Introductionmentioning

confidence: 99%

A Remarkable Multitasking Double Spiropyran: Bidirectional Visible-Light Switching of Polymer-Coated Surfaces with Dual Redox and Proton Gating

et al. 2016

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Smart or functional surfaces that exhibit complex multimodal responsivity, e.g., to light, heat, pH, etc., although highly desirable, require a combination of distinct functional units to achieve each type of response and present a challenge in achieving combinations that can avoid cross-talk between the units, such as excited-state quenching. Compounds that exhibit multiple switching modalities help overcome this challenge and drastically reduce the synthetic cost and complexity. Here we show that a bis-spiropyran photochrome, which is formed through coupling at the indoline 5-position using redox chemistry, exhibits pH-gated photochromism, with opening of the spiro moiety by irradiation with UV light and the expected reversion by either heating or irradiation with visible light gated by protonation/deprotonation. Remarkably, when the photochrome is oxidized to its dicationic form, bis-spiropyran(2+), visible light can be used instead of UV light to switch between the spiro and merocyanine forms, with locking and unlocking of each state achieved by protonation/deprotonation. The formation of the bis-spiropyran unit by electrochemical coupling is exploited to generate "smart surfaces", i.e., polymer-modified electrodes, avoiding the need to introduce an ancillary functional group for polymerization and the concomitant potential for cross-talk. The approach taken means not only that the multiresponsive properties of the bis-spiropyran are retained upon immobilization but also that the effective switching rate can be enhanced dramatically.

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“…51,52 The ringopening was manifested in a disappearance of the redox waves at 0.3 and 0.6 V (i.e., the oxidation of 1c to 1c + and 1c 2+ , respectively) and an increase in the intensity of the oxidation waves above 0.8 V. Cyclic voltammetry between −0.2 and 1.4 V resulted in ring closure to restore the closed polymer poly-1c (Figure 3), as observed for the monomer when electropolymerizing with the open form (vide supra).…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…At λ exc 785 nm, resonance enhancement is expected for the polaronic states (as observed before for a related sexithiophene polymer). 52 Spectro-electrochemistry reveals the changes in the resonance Raman spectra as the potential is varied (Figure 6). The resonance enhancement of Raman scattering from either the central switch unit or of the tetrathiophene unit in the polymer can be expected depending on the localization of the polarons.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Electrochemical Switching of Conductance with Diarylethene-Based Redox-Active Polymers

et al. 2012

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Reversible switching of conductance using redox triggered switching of a polymer-modified electrode is demonstrated. A bifunctional monomer comprising a central electroswitchable core and two bithiophene units enables formation of a film through anodic electropolymerization. The conductivity of the polymer can be switched electrochemically in a reversible manner by redox triggered opening and closing of the diarylethene unit. In the closed state, the conductivity of the modified electrode is higher than in the open state.

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In situ monitoring of polymerredox states by resonance μRaman spectroscopy and its applications in polymer modified microfluidic channels

Cited by 7 publications

References 22 publications

Reversible Charge Trapping in Bis-Carbazole-Diimide Redox Polymers with Complete Luminescence Quenching Enabling Nondestructive Read-Out by Resonance Raman Spectroscopy

Reversible Charge Trapping in Bis-Carbazole-Diimide Redox Polymers with Complete Luminescence Quenching Enabling Nondestructive Read-Out by Resonance Raman Spectroscopy

A Remarkable Multitasking Double Spiropyran: Bidirectional Visible-Light Switching of Polymer-Coated Surfaces with Dual Redox and Proton Gating

Electrochemical Switching of Conductance with Diarylethene-Based Redox-Active Polymers

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