The Quell Architecture: A Confined Supramolecular Bi-Stable Unit

This work proposes a chemically grounded design for a classical supramolecular computing cell built entirely from experimentally established molecular components. Each cell, referred to as a Quell unit, consists of three functional guest molecules—a bistable rotaxane, an azobenzene-based molecular gate, and a Ru(II)/Ru(III) redox center—encapsulated within a rigid metal–organic cage host. Confinement within the cage enforces fixed spatial relationships between these components and suppresses diffusional and conformational noise. The integrated assembly behaves as a classical bistable unit at the molecular scale: the rotaxane stores a binary mechanical state, the azobenzene gate controls access to the switching pathway, and the redox center provides an electrically addressable bias that favors one state over the other. Metal–organic cages of the type considered here are known to form ordered crystalline arrays in the solid state. A bulk Quell crystal is therefore a dense lattice of identical, structurally confined logic–memory units occupying fixed positions in three-dimensional space. The information density of such a material is determined primarily by molecular packing constraints and can reach on the order of 10^21–10^22 potential bits per cubic inch under conservative assumptions. The design relies exclusively on molecular behaviors that have already been demonstrated in the literature—bistable rotaxanes, azobenzene photoisomerization, reversible Ru(II)/Ru(III) redox transitions, and robust cage encapsulation—combined in a configuration that leverages confinement to achieve operational determinism [1–5]. This manuscript outlines the structural basis, operational mechanism, and scaling implications of the Quell architecture as a starting point for experimental exploration of classical molecular computing media.