Acid-Base Switching of Tautomerism and Conformation of a Dioxoporphyrin for Integrated Binary Subtraction

Journal article, 2014

Compared with most of the reported logic devices based on the supramolecular approach, systems based on individual molecules can avoid challenging construction requirements. In this work, a novel dioxoporphyrin DPH22 was synthesized, and two of its tautomers were characterized by single crystal X-ray diffraction analyses. DPH22 exhibits multichannel controllable stepwise tautomerization, protonation and deprotonation processes by its interactions with H+ and F-. Using the addition of H+ and F- as the inputs and UV-vis absorption values at 412, 510, 562 and 603 nm as outputs, the controlled tautomerism of DPH22 has been successfully used for the construction of an integrated molecular level half-subtractor and comparator. Besides, this acid and base switched tautomerism turns out to be reversible, endowing the system with ease of reset and recycling, and there is no need to modulate complicated intermolecular interactions and electron/charge transfer processes.