Photochromic and photoresponsive properties of optically active poly(methacrylate)s with pendantL-leucine,L-valine andL-proline residues connected to 4-aminoazobenzene moieties

Carlini, Carlo; Fissi, Adriano; Galletti, Anna Maria Raspolli; Sbrana, Glauco

doi:10.1002/1521-3935(20000701)201:11<1161::aid-macp1161>3.0.co;2-r

Cited by 4 publications

(6 citation statements)

References 32 publications

(37 reference statements)

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“…257 Another series of studies concentrated on polymethacrylates incorporating chiral side chains with azobenzene groups. [258][259][260][261] The photoisomerization of the azobenzene groups was studied in relation to the circular dichroism spectra in solution. H-bonding and dipolar interactions (in the case of donor-acceptor substituted azobenzenes) play an important role in the photoinduced phenomena.…”

Section: B Helical Structure Of Macromoleculesmentioning

confidence: 99%

Photoinduced Motions in Azo-Containing Polymers

2002

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Section: B Helical Structure Of Macromoleculesmentioning

confidence: 99%

Photoinduced Motions in Azo-Containing Polymers

2002

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“…As the absorbance of the cis isomer in this region is very small, this method provides a reasonable estimate of isomeric composition. 64 According to this method, the UVinduced photostationary state in the films shown in Figure 3B is 19% cis. In contrast, the UV-induced photostationary state of HPA-10-PPV in THF solution is 76% cis (data not shown).…”

Section: Resultsmentioning

confidence: 99%

Photomodulated PPV Emission in a Photochromic Polymer Film

and

Harbron

2007

J. Phys. Chem. C

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We present studies of fluorescence intensity modulation in neat films of a photochromic poly(p-phenylenevinylene) (PPV) derivative. Poly(2-hexyloxy-5-((10-(4-(phenylazo)phenoxy)decyl)oxy)-1,4-phenylenevinylene) (HPA-10-PPV), a PPV derivative functionalized with photoaddressable azobenzene side chains, is known to undergo modulated changes in fluorescence intensity upon azobenzene isomerization in solution. These changes are caused by nonradiative transfer of excitation energy from the PPV backbone to the azobenzene moiety. The efficiency of energy transfer is higher for the cis azobenzene isomer than for trans, a difference that enables fluorescence intensity modulation. Upon film formation, the fluorescence spectra of neat HPA-10-PPV films undergo a red shift of ca. 30 nm compared to those measured in dilute solution. Application of ultraviolet irradiation to induce trans → cis azobenzene isomerization yields a reduction in fluorescence intensity in HPA-10-PPV films that is reversed upon azobenzene cis → trans back isomerization. These reversible intensity changes can be cycled many times in the film with a modulation efficiency that is virtually identical to that measured in dilute solution. The isomeric state of the azobenzene side chains at the time of film casting has a negligible impact on film fluorescence properties and subsequent isomerization behavior in the film. This result implies that the azobenzene has ample free volume for isomerization in the film and that its isomeric state does not substantially impact film morphology in a way that affects the fluorescence. Spatial control of fluorescence intensity in HPA-10-PPV films is demonstrated by inscribing an image with increased fluorescence intensity on a lower intensity background. The successful photomodulation of fluorescence intensity in polymer films further demonstrates the potential for photochromic conjugated polymers as a class to find applications in optical data storage.

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“…[76][77][78][79][80] Such polymers commonly include photosensitive achiral rod-like mesogenic azobenzene moieties on their side chains (Figure 7A-a). A chiral amino acid group, such as lefthanded alanine, leucine, valine, or proline, [76,77] with a carbon stereo-center and left-handed lactic [78,79] as well as appropriate comparability with the polymers, was interposed between the backbone and azobenzene moieties on the side chain to induce chirality of the compounds. This category of polymers exhibited optical chirality in both solutions and films due to asymmetric electron transitions, which subsequently induced a dipole interaction between two adjacent side chains, and hence presented exciton splitting of the CD spectrum.…”

Section: Photoresponsive Helical Polymersmentioning

confidence: 99%

Section: Photoresponsive Chiro‐optical Mesogenic Helical Soft Materialsmentioning

confidence: 99%

Photoprogrammable Mesogenic Soft Helical Architectures: A Promising Avenue toward Future Chiro‐Optics

Zheng

2020

Advanced Materials

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reflection, exhibits photonic localization in the band gap determined by the period in the case of normal incidence. [6] Similarly, a helical superstructure composed of chiral chromophores leads to absorption differences between left-and right-handed CPL, referred to as the Cotton effect, owing to the asymmetry of chiral chromophores or that of achiral chromophores induced by a chiral system. [7] Chiro-optical characteristics in helical supramolecular assemblies and superstructures have attracted tremendous attention in the past decade, especially in self-organized mesogenic helical soft matter, which is an emerging scientific frontier in chemistry, functional materials, soft matter physics, biological medicine, and even sensor physics. Mesogenic soft matter, defined as soft condensed matter with molecules containing single or multiple anisotropic mesogen moieties, is distinct from common soft condensed matter in terms of molecular arrangement, interaction, and specific optical chirality, although the "soft" characteristic is still maintained. A primary reason for the softness is related to the responses of this type of matter to multiple external stimuli, such as electric fields, heat, light, mechanical forces, and even acoustic fields. [8] The control and manipulation of such soft materials by light is always more desirable than that of other stimuli due to the prominent advantages of non-contact, wireless, remote, and high-resolution control, which enable numerous unprecedented chiro-optical applications. [9] Optically, another fascinating feature of these materials is their molecular self-organization behavior, which can establish an ordered and regular arrangement with a structural parameter (≈µm) much larger than the single-molecule scale (≈nm) through the weak non-covalent molecular interaction, rather than the chemical bonds that normally exist in

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Photochromic and photoresponsive properties of optically active poly(methacrylate)s with pendantL-leucine,L-valine andL-proline residues connected to 4-aminoazobenzene moieties

Cited by 4 publications

References 32 publications

Photoinduced Motions in Azo-Containing Polymers

Photoinduced Motions in Azo-Containing Polymers

Photomodulated PPV Emission in a Photochromic Polymer Film

Photoprogrammable Mesogenic Soft Helical Architectures: A Promising Avenue toward Future Chiro‐Optics

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