Due to the small size and biocompatibility of molecules, molecular logic-based computation is a gateway to the informational basis of life processes. Logic-based computation operates widely with discrete molecules of up to nanometric sizes. The contribution of molecule-based bulk materials of milli/centimetric size to the field has begun in more recent years. However, artificial molecule-based meso-scale systems which intrinsically perform logic operations are very rare. Here, we show that self-assembled systems consisting of cyclophane octacarboxylates and a cationic surfactant can perform such functions, where a membrane itself behaves as a Reset-Set Flip-Flop which is integrated with 7 more logic elements. Now that molecular logic-based computation operates across a wide range of contiguous size-scales, the way opens for its general use in information processing aspects of biology and synthetic biology.

Switchable cyclophanes allow capture/release of guests to control their properties.

Electron/proton transfers in water proceeding from ground/excited states are the elementary reactions of chemistry. These reactions of an iconic class of molecules─polypyridineRu(II)─are now controlled by capturing or releasing three of them with hosts that are shape-switchable. Reversible erection or collapse of the host walls allows such switchability. Some reaction rates are suppressed by factors of up to 120 by inclusive binding of the metal complexes. This puts nanometric coordination chemistry in a box that can be open or shut as necessary. Such second-sphere complexation can allow considerable control to be exerted on photocatalysis, electrocatalysis, and luminescent sensing involving polypyridineRu(II) compounds. The capturing states of hosts are symmetry-matched to guests for selective binding and display submicromolar affinities. A perching complex, which is an intermediate state between capturing and releasing states, is also demonstrated.

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.

The fluorescence of sensors 1 and 6, which are designed in terms of photoinduced electron transfer (PET), is switched 'on' by factors of 15 and 6 with avidin in a rather selective manner. Sensors 3 and 7, simpler derivatives of 1, are switched 'on' by factors of 16 and 7.5 with bovine serum albumin, though at 30-fold higher concentrations.

Proton-driven YES and PASS 1 molecular logic tags based on anthracene and 4-aminonaphthalimide fluorophores, emitting blue and green, respectively, are employed on amino-terminated polyethylene glycol-polystyrene and aminopropyl silica particles. The (YES+PASS 1) logic combination is also a distinguishable tag in both colours. The scope of such tags is delineated.

When the question ‘What has supramolecular chemistry done for us?’ arises, we need to answer it in the full realisation that ‘us’ refers to everyone in the supramolecular chemistry community and th...

In the 21st century, information has become the most valuable resource that is available to modern societies. Thus, great efforts have been made to develop new information processing and storage techniques. Chemistry can offer a wide variety of computing paradigms that are closely related to the natural processes found in living organisms (e.g., in the nervous systems of animals). Moreover, these phenomena cannot be reproduced easily by solely using silicon-based technology. Other great advantages of molecular scale systems include their simplicity and the diversity of interactions that occur among them. Thus, devices constructed using chemical entities may be programmed to deal with different information carriers (photons, electrons, ions, and molecules), possibly surpassing the capabilities of classic electronic circuits. (C) 2016 Elsevier B.V. All rights reserved.

Following a brief introduction to the principle of fluorescent PET (photoinduced electron transfer) sensors and switches, the outputs of laboratories in various countries from the past year or two are categorized and critically discussed. Emphasis is placed on the molecular design and the experimental outcomes in terms of target-induced fluorescence enhancements and input/output wavelengths. The handling of single targets takes up a major fraction of the review, but the extension to multiple targets is also illustrated. Conceptually new channels of investigation are opened up by the latter approach, e.g.'lab-on-a-molecule' systems and molecular keypad locks. The growing trends of theoretically-fortified design and intracellular application are pointed out.

AbstractThe entitled conversion is applied to synthesize helquinoline (I) which is a novel trans‐disubstituted tetrahydroquinoline alkaloid isolated from the North Sea bacterium Janibacter limosus Hel 1.

It is an exciting era for molecular computation because molecular logic gates are being pushed in new directions. The use of sulfur rather than the commonplace nitrogen as the key receptor atom in metal ion sensors is one of these directions; plant cells coming within the jurisdiction of fluorescent molecular thermometers is another, combining photochromism with voltammetry for molecular electronics is yet another. Two-input logic gates benefit from old ideas such as rectifying bilayer electrodes, cyclodextrin-enhanced room-temperature phosphorescence, steric hindrance, the polymerase chain reaction, charge transfer absorption of donor–acceptor complexes and lectin–glycocluster interactions. Furthermore, the concept of photo-uncaging enables rational ways of concatenating logic gates. Computational concepts are also applied to potential cancer theranostics and to the selective monitoring of neurotransmitters in situ. Higher numbers of inputs are also accommodated with the concept of functional integration of gates, where complex input–output patterns are sought out and analysed. Molecular emulation of computational components such as demultiplexers and parity generators/checkers are achieved in related ways. Complexity of another order is tackled with molecular edge detection routines.

Molecular logic-based computation is a broad umbrella covering molecular sensors at its simplest level and logic gate arrays involving steadily increasing levels of parallel and serial integration. The fluorescent PET (photoinduced electron transfer) switching principle remains a loyal servant of this entire field. Applications arise from the convenient operation of molecular information processors in very small spaces.

Yttrium triflate or triflic acid catalysed Povarov reaction of methyl anthranilate with ethyl vinyl ether, both as aldehyde surrogate and as alkene, gave the desired 2-methyl-4-ethoxytetrahydroquinoline diastereoisomers as the major products along with four component coupling von Miller adducts. A proton NMR-study, using yttrium triflate as catalyst, revealed that the cis-diastereoisomers were the initial major products in both the Povarov and von Miller reactions but that these isomerised to the trans-diastereoisomers under the reaction conditions. Two distinct pathways for forming von Miller adducts were uncovered with the initial Povarov products being converted to von Miller adducts under the reaction conditions. Replacement of the 4-ethoxy with a 4-methoxy group under acidic conditions gave predominantly the trans-diastereoisomer, which was subsequently converted to a cis/trans mixture of the tetrahydroquinoline antibiotic helquinoline. It was also possible to convert the von Miller products to Povarov products under acidic conditions.

Molecular information gathering and processing-a young field of applied chemistry-is undergoing good growth. The progress is occurring both in terms of conceptual development and in terms of the strengthening of older concepts with new examples. This review critically surveys these two broad avenues. We consider some cases where molecules emulate one of the building blocks of electronic logic gates. We then examine molecular emulation of various Boolean logic gates carrying one, two or three inputs. Some single-input gates are popular information gathering devices. Special systems, such as 'lab-on-a-molecule' and molecular key-pad locks, also receive attention. A situation deviating from the Boolean blueprint is also discussed. Some pointers are offered for maintaining the upward curve of the field.