http://academic.oup.com/chemlett en-us Tue, 01 Jul 2025 00:00:00 GMT Tue, 01 Jul 2025 15:12:40 GMT Silverchair https://academic.oup.com/chemlett/advance-article/doi/10.1093/chemle/upaf129/8180592?rss=1 Tue, 01 Jul 2025 00:00:00 GMT <span class="paragraphSection"><div class="boxTitle">Abstract</div>The photo- and pH-responsive physicochemical properties of the neutral nitrobenzospiropyran derivative (HSP) at toluene/acidic-water interface were investigated. HSP undergoes photoisomerization to form zwitterionic merocyanine (HMC), and the protonation of HMC makes it cationic state. Rapid conversion of the interfacial tension at the toluene/water interface was achieved by the photoisomerization and protonation of HSP. In addition, the applicability of light-induced control in emulsion formation was evaluated.</span> upaf129 10.1093/chemle/upaf129 http://doi.org/10.1093/chemle/upaf129 https://academic.oup.com/chemlett/article/doi/10.1093/chemle/upaf085/8138103?rss=1 Tue, 20 May 2025 00:00:00 GMT <span class="paragraphSection"><div class="boxTitle">Abstract</div>The key factors determining the feasibility of epimerization of <span style="font-style:italic;">P</span>-spiro chiral tetraaminophosphoniums have been elucidated by DFT calculations. <span style="font-style:italic;">P</span>-Spirochirality inversion proceeds through the formation of a pentacoordinate phosphorane by the nucleophilic attack of the counter ion and the subsequent pseudorotation via the square pyramidal transition state (TS). The TS energies are highly dependent on the nitrogen substituents of the aminophosphoniums and the counter ion structure. The energy barrier for the TS significantly increases by the introduction of methyl groups on two of the four nitrogen atoms of the aminophosphonium because of their steric repulsion. On the other hand, the energy barrier decreases when oxyanions, such as nitronate and phenoxide, are involved due to the effective interaction of the oxyanion p-orbitals with P–N σ* orbitals unlike the case with chloride ions. These profiles will account for our experimental observations.</span> 54 5 upaf085 10.1093/chemle/upaf085 http://doi.org/10.1093/chemle/upaf085