Counterion-free molecular quantum-dot cellular automata using mixed valence zwitterions – A double-dot derivative of the [closo-1-CB9H10]− cluster

Molecular quantum-dot cellular automata (QCA) paradigm is a promising approach to molecular electronics. QCA cells can be implemented using mixed-valence compounds. However, the existence of counterions can perturb the local electric field and thus is detrimental to information encoding and processing. Here we examine the feasibility of using charge neutral, zwitterionic mixed-valence complex as QCA cells in which the positive and negative charges are found at different yet fixed locations within the molecule and therefore counterion effects are more predictable and controllable. A double-dot model molecule based on the derivative of the 1-carba-closo-decaborate monoanion [closo-1-CB9H10]− is investigated using computational chemistry techniques. The model molecule demonstrates bistability and switchability.