Efficient Cycloreversion Reaction of a Diarylethene Derivative in Higher Excited States Attained by Off-Resonant Simultaneous Two-Photon Absorption

Abstract

Off-resonant excitation of the closed-ring isomer of a photochromic diarylethene derivative at 730 nm induced the efficient cycloreversion reaction with a yield of ∼20%, while the reaction yield was only 2% under one-photon excitation at 365 nm. Excitation wavelength dependence of the one-photon cycloreversion reaction yield under steady-state irradiation in a wide wavelength range showed that the specific electronic state leading to the large cycloreversion reaction yield, which is originally forbidden in the optical transition but partially allowed owing to the low symmetry of the molecule, is spectrally overlapped with the electronic state accessible by the allowed one-photon optical transition in the UV region. Femtosecond transient absorption spectroscopy also revealed that the off-resonant two-photon excitation preferentially pumped the molecule into the specific state, leading to the 10-fold enhancement of the cycloreversion reaction.

Solid Materials with Near‐Infrared‐Induced Fluorescence Modulation

“…Although this value is averaged over all the illuminated area and, hence, is a lower limit of the actual temperatures reached in the vicinity of the gold nanostructures, it unambiguously demonstrates their capacity of photothermally melting TdOH (and even higher‐ T m PCMs) at NIR intensities that are considerably inferior than those required for inducing multiphoton operation of regular photochromes. [ 34–40 ]…”

“…Although this value is averaged over all the illuminated area and, hence, is a lower limit of the actual temperatures reached in the vicinity of the gold nanostructures, it unambiguously demonstrates their capacity of photothermally melting TdOH (and even higher-T m PCMs) at NIR intensities that are considerably inferior than those required for inducing multiphoton operation of regular photochromes. [34][35][36][37][38][39][40] Detailed analysis of the behavior of NIAD-4/TdOH-AuNS@ paper uncovered other additional advantages of our approach toward NIR-driven emission modulation. First, multiple consecutive cycles (up to 100) of light-induced fluorescence modulation could be measured without apparent degradation by repeatedly switching on and off the NIR source (Figure 2e), which demonstrates the large fatigue resistance of our switchable materials.…”

“…[ 29 ] Actually, making photochromic compounds sensitive to NIR radiation still remains a challenge that requires intricate synthetic procedures [ 30–33 ] and/or multiphoton excitation under high irradiation powers. [ 34–40 ] As such, their incorporation into more complex systems to attain NIR‐induced luminescence modulation has been largely hampered to date.…”

Donor–acceptor–acceptor-type near-infrared fluorophores that contain dithienophosphole oxide and boryl groups: effect of the boryl group on the nonradiative decay

“…To quantitatively evaluate the photostability of these compounds, we attempted to determine their total quantum yield of photodecomposition (F dec ), which is dened as the sum of the quantum yields of all photoreactions producing products under light irradiation. [37][38][39] The F dec values estimated were considered to be the minimum possible values, as F dec is underestimated when the decomposition products absorb light at the monitored wavelength.…”

“On-The-Fly” Non-Adiabatic Dynamics Simulations on Photoinduced Ring-Closing Reaction of a Nucleoside-Based Diarylethene Photoswitch

“…An in-depth understanding of relevant photophysical and photochemical processes of photoswitches is of fundamental importance for the design of novel photoswitches with better performances. Therefore, many time-resolved spectroscopical works have been carried out to explore the underlying photochromic mechanism of various diarylethenes [ 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 ]. Particularly, Jäschke’s group applied femtosecond transient absorption spectroscopy to study the photoinduced pericyclic and cycloreversion reactions of PS-IV [ 36 , 37 ].…”