Utroša Petra, Carroll Joshua A, Žagar Ema, Pahovnik David, Barner-Kowollik Christopher
Department of Polymer Chemistry and Technology, National Institute of Chemistry, Hajdrihova 19, 1000, Ljubljana, Slovenia.
Centre for Materials Science, School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, QLD 4000, Brisbane, Australia.
Chemistry. 2024 Jul 2;30(37):e202400820. doi: 10.1002/chem.202400820. Epub 2024 May 17.
Photoacids and bases allow remote control over pH in reaction solutions, which is of fundamental importance to an array of applications. Herein, we determine the wavelength-by-wavelength resolved photoreactivity of triarylsulfonium hexafluorophosphate salts as a representative photoacid generator and p-(benzoyl)benzyl triethylammonium tetraphenylborate as a photobase generator, constructing a wavelength-resolved photochemical action plot for each of the compounds. We monitor the pH change of the solution on-line within the cavity of the laser vial and demonstrate a marked mismatch between the absorption spectrum of the photoacid and base with the photochemical action plot, unveiling reactivity at very low absorptivities. Our findings are of critical importance for the use of photoacids and bases, unambiguously demonstrating that absorption is no guide to chemical reactivity with critical consequences for the wavelength employed in applications of photoacids and bases.
光酸和光碱能够远程控制反应溶液的pH值，这对于一系列应用至关重要。在此，我们测定了六氟磷酸三芳基锍盐作为代表性光酸产生剂以及对（苯甲酰基）苄基三乙铵四苯基硼酸盐作为光碱产生剂的逐波长分辨光反应性，为每种化合物构建了波长分辨光化学作用图。我们在激光小瓶腔内在线监测溶液的pH变化，并证明光酸和光碱的吸收光谱与光化学作用图之间存在明显不匹配，揭示了在非常低的吸光度下的反应性。我们的发现对于光酸和光碱的使用至关重要，明确表明吸收并非化学反应性的指南，这对光酸和光碱应用中所采用的波长具有关键影响。
