Materials that can be switched between low and high thermal conductivity states would advance the control and conversion of thermal energy. Employing in situ time-domain thermoreflectance (TDTR) and in situ synchrotron X-ray scattering, we report a reversible, light-responsive azobenzene polymer that switches between high (0.35 W m−1K−1) and low thermal conductivity (0.10 W m−1K−1) states. This threefold change in the thermal conductivity is achieved by modulation of chain alignment resulted from the conformational transition between planar (
Caging groups are photoremovable protecting groups that render a molecule biologically inactive until light illumination, thereby allowing for temporal and spatial control of activity. While nitrobenzyl‐based caging groups have advantageous synthetic and photochemical properties, red shifting of the absorption spectrum through chemical modification has led to reduced decaging efficiency. 6‐Nitropiperonyloxymethylene (NPOM), a group with broad applicability in the caging of heterocyclic structures, in particular nucleic acids, traditionally requires ultraviolet (UV) irradiation for decaging. Herein, we investigated the decaging properties of NPOM under near visible light (400–450 nm) using N3‐caged 5’‐dimethoxytrityl (DMTr)‐thymidine as a substrate. To our surprise, we discovered highly efficient decaging at wavelengths outside the UV range, in particular when compared to other nitrobenzyl chromophores. These results have implications in the selection of light sources for photoactivation and for sequential photolysis to achieve selective control of biological processes.
more » « less- NSF-PAR ID:
- 10402828
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- ChemPhotoChem
- Volume:
- 7
- Issue:
- 3
- ISSN:
- 2367-0932
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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