Mechanistic Basis for Red Light Switching of Azonium Ions

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989100%3A27740%2F23%3A10254101" target="_blank" >RIV/61989100:27740/23:10254101 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/61989592:15640/23:73621898

Výsledek na webu

<a href="https://pubs.acs.org/doi/10.1021/jacs.3c06157" target="_blank" >https://pubs.acs.org/doi/10.1021/jacs.3c06157</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/jacs.3c06157" target="_blank" >10.1021/jacs.3c06157</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Mechanistic Basis for Red Light Switching of Azonium Ions

Popis výsledku v původním jazyce

Azonium ions formed by the protonation of tetra-ortho-methoxy-substituted aminoazobenzenes photoisomerize with red light under physiological conditions. This property makes them attractive as molecular tools for the photocontrol of physiological processes, for example, in photopharmacology. However, a mechanistic understanding of the photoisomerization process and subsequent thermal relaxation is necessary for the rational application of these compounds as well as for guiding the design of derivatives with improved properties. Using a combination of sub-ps/ns transient absorption measurements and quantum chemical calculations, we show that the absorption of a photon by the protonated E-H+ form of the photoswitch causes rapid (ps) isomerization to the protonated Z-H+ form, which can also absorb red light. Proton transfer to solvent then occurs on a microsecond time scale, leading to an equilibrium between Z and Z-H+ species, the position of which depends on the solution pH. Whereas thermal isomerization of the neutral Z form to the neutral E form is slow (similar to 0.001 s(-1)), thermal isomerization of Z-H+ to E-H+ is rapid (similar to 100 s(-1)), so the solution pH also governs the rate at which E/E-H+ concentrations are restored after a light pulse. This analysis provides the first complete mechanistic picture that explains the observed intricate photoswitching behavior of azonium ions at a range of pH values. It further suggests features of azonium ions that could be targeted for improvement to enhance the applicability of these compounds for the photocontrol of biomolecules.

Název v anglickém jazyce

Mechanistic Basis for Red Light Switching of Azonium Ions

Popis výsledku anglicky

Azonium ions formed by the protonation of tetra-ortho-methoxy-substituted aminoazobenzenes photoisomerize with red light under physiological conditions. This property makes them attractive as molecular tools for the photocontrol of physiological processes, for example, in photopharmacology. However, a mechanistic understanding of the photoisomerization process and subsequent thermal relaxation is necessary for the rational application of these compounds as well as for guiding the design of derivatives with improved properties. Using a combination of sub-ps/ns transient absorption measurements and quantum chemical calculations, we show that the absorption of a photon by the protonated E-H+ form of the photoswitch causes rapid (ps) isomerization to the protonated Z-H+ form, which can also absorb red light. Proton transfer to solvent then occurs on a microsecond time scale, leading to an equilibrium between Z and Z-H+ species, the position of which depends on the solution pH. Whereas thermal isomerization of the neutral Z form to the neutral E form is slow (similar to 0.001 s(-1)), thermal isomerization of Z-H+ to E-H+ is rapid (similar to 100 s(-1)), so the solution pH also governs the rate at which E/E-H+ concentrations are restored after a light pulse. This analysis provides the first complete mechanistic picture that explains the observed intricate photoswitching behavior of azonium ions at a range of pH values. It further suggests features of azonium ions that could be targeted for improvement to enhance the applicability of these compounds for the photocontrol of biomolecules.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10400 - Chemical sciences

Projekt

—

Návaznosti

—

Rok uplatnění

2023

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of the American Chemical Society

ISSN

0002-7863

e-ISSN

1520-5126

Svazek periodika

145

Číslo periodika v rámci svazku

36

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

9

Strana od-do

19894-19902

Kód UT WoS článku

001061672500001

EID výsledku v databázi Scopus

2-s2.0-85171203333