Molecular memory with downstream logic processing exemplified by switchable and self-indicating guest capture and release

Abstract

Molecular-logic based computation (MLBC) has grown by accumulating many examples of combinational logic gates and a few sequential variants. In spite of many inspirations being available in biology, there are virtually no examples of MLBC in chemistry where sequential and combinational operations are integrated. Here we report a simple alcohol-ketone redox interconversion which switches a macrocycle between a large or small cavity, with erect aromatic walls which create a deep hydrophobic space or with collapsed walls respectively. Small aromatic guests can be captured or released in an all or none manner upon chemical command. During capture, the fluorescence of the alcohol macrocycle is quenched via fluorescent photoinduced electron transfer switching, meaning that its occupancy state is self-indicated. This represents a chemically-driven RS Flip-Flop, one of whose outputs is fed into an INHIBIT gate. Processing of outputs from memory stores is seen in the injection of packaged neurotransmitters into synaptic clefts for onward neural signalling. Overall, capture-release phenomena from discrete supermolecules now have a Boolean basis.

Stimuli‐Responsive Circularly Polarized Organic Ultralong Room Temperature Phosphorescence

“…In light of the unique features of the photo/thermal responsive reversible CP‐OURTP emission of these purely organic materials, a new‐concept integrated combinational logic encryption device was designed and fabricated using S/R‐COOCz , a normal yellow OURTP molecule ( CPM ), a blue fluorescent molecule (9‐bromoanthracene), and an inorganic phosphor (Figures b and S23–S25) . This integrated combinational logic encryption device contains one INHIBIT and one OR logic gate (Figure S24).…”

Supra-molecular agents running tasks intelligently (SMARTI): recent developments in molecular logic-based computation

“…We used these general considerations to design the specific case 55/56. 219 When dissolved in alkaline water, dialcohol 56 contains a reasonably deep hydrophobic cavity which has the appropriate size, shape and nature 220 to inclusively bind the dicationic guest 57. On the other hand, diketone 55 has collapsed phenylene walls owing to their pi-delocalization with the carbonyls and is therefore unable to hold this guest.…”

“…Somewhat similar serial gate integration was seen in 56 acting as a receptor for 57. 219 The end result is the production of 'current signal 2 ' because switch 1 and switch 2 are now both 'on'. This end result is visualized as a fluorescence output by using a reporter containing a fluorophore-quencher assembly which is disassembled by the action of 'current signal 2 '.…”

“…Physical electronic representation of a RS flip-flop, which is found in a part of the behaviour of 55/56 219. …”

A Supramolecular Counter Circuit Based on Cyanine Dye Assembly

“…Sequential logics are another kind of electronic devices, whose outputsd epend on both present and previous inputs. The memory functione ndows the sequential logic circuits huge possibilities in practice, but posesagreat challengef or designing their molecular analogues.D uring the last two decades, only af ew molecular sequential circuits have been reported, and their functions were primarily limited in keyboard lock, [8] flip-flop, [9] and register. [10] Thus, designing versatile sequential devices at the molecular level is attractive, and urgently needed concerning the blossom of molecularc omputation.…”