Design of Light‐Induced Molecular Switcher for the Driver of the Quantum Cellular Automata (QCA) Based on the Transition through the Intramolecular Charge Transfer (ICT) Structure

Abstract

The design of light‐induced switcher for the molecular QCA driver was discussed. The driver‐cell with two connected chromophores was proposed as a basic model of the molecular light‐induced trigger. One of the chromophores will conjugate with a left diagonal and the second chromophore will conjugate with a right diagonal. Some differences between two chromophores can allow selective controlling of the switch to the left or to the right. The following three‐steps mechanism for QCA switcher was suggested – light‐induced transition through ICT area (a), initiation of the driver‘s polarization (b) and the beginning of the signal transition to the other cells (c). The principal physical characteristics of the driver‘s trigger was proposed, and the corresponding chemical implementation was discussed. Three kinds of processes leading to ICT were discussed as mechanisms suggested for potential switchers: 1) Irradiation leading to the ICT excited state; 2) Chemical reaction with ICT transition state; 3) Excited State Intramolecular Proton Transfer (ESIPT). The common features of these processes are the non‐radiative transition to the initial state after excitation, with the back transition going through the highly polar charge transfer (CT) area.

Zwitterionic Mixed-Valence Species for the Design of Neutral Clocked Molecular Quantum-Dot Cellular Automata

“…Some prerequisites must be met, in particular: a two-dot QCA compound must have (i) a stable mixed-valence state with a rather large comproportionation constant; (ii) a moderate coupling between the two redox centers (rapid exchange of the charge between the two sites is necessary); and less importantly, (iii) the capability of functionalization for surface binding in ordered arrays. Large comproportionation constants and moderate coupling between the two redox centers are typically observed for partially localized Class-II systems according to the Robin–Day classification of MV compounds. , Several two-dot and four-dot organic and organometallic QCA candidate MV compounds have been proposed either theoretically − or experimentally, − more or less successfully for QCA applications.…”