Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, UP 208016, India.
Institute for Organic Chemistry and Chemical Biology, Goethe-University Frankfurt, 60438 Frankfurt, Germany.
J Phys Chem Lett. 2021 Jun 17;12(23):5463-5468. doi: 10.1021/acs.jpclett.1c01186. Epub 2021 Jun 4.
A new class of pyridine-based spiropyran (SP) shows photoinduced reversible switching between the closed SP and ring-opened merocyanine (MC). We show that a condensed crystalline monolayer of SP on graphite can be quantitatively converted to MC upon UV irradiation. In solution only ∼10% of SP can be transformed to MC because of the establishment of a photostationary state. Using an electrical field applied by a scanning tunneling microscopy (STM) tip, single molecules are reversibly switched between SP and MC forms in their condensed phases without any threshold voltage at ambient conditions. The microscopic structure of submonolayer films of SP and MC are investigated using atomic force microscopy (AFM) and STM.
一类新型吡啶基螺吡喃（SP）在闭合的 SP 和开环的甲川菁（MC）之间表现出光诱导的可逆转换。我们表明，在石墨上的 SP 凝聚结晶单层可以在紫外线照射下定量地转化为 MC。在溶液中，由于光稳定态的建立，只有约 10%的 SP 可以转化为 MC。使用扫描隧道显微镜（STM）尖端施加的电场，在环境条件下无需任何阈值电压，单分子在其凝聚相中在 SP 和 MC 形式之间可逆切换。使用原子力显微镜（AFM）和 STM 研究了 SP 和 MC 的亚单层膜的微观结构。
