Logic gates design

Another very good example of the mapping procedure, which can be practiced to design a semiclassical intramolecular logic gate molecular circuit, is the nontrivial... 

Renaud N, Joachim C (2008) Design and stability of NOR and NAND logic gates constructed with three quantum states. Phys Rev A 78 062316... 

S. Tuchman, S. Sideman, S. Kenig, and N. Lotan, Enzyme based logic gates controlled by outside signals principles and design, in Molecular Electronics and Molecular Electronic Devices, K. Sienicki, Ed., Vol. HI, CRC Press, Boca Raton, FL, 1994, pp. 223-238. 

Figure 9. (a) Schematic representation of the five-module format of a photoactive triad which is switchable only by the simultaneous presence of a pair of ions. This design involves the multiple application of the ideas in Figure 1. The four distinct situations are shown. Note that the presence of each guest ion in its selective receptor only suppresses that particular electron transfer path. The mutually exclusive selectivity of each receptor is symbolized by the different hole sizes. All electron transfer activity ceases when both guest ions have been received by the appropriate receptors. The case is an AND logic gate at the molecular scale. While this uses only two ionic inputs, the principle established here should be extensible to accommodate three inputs or more, (b) An example illustrating the principles of part (a) from an extension of the aminomethyl aromatic family. The case shown applies to the situation (iv) in part (a) where both receptors are occupied. It is only then that luminescence is switched "on". Protons and sodium ions are the relevant ionic inputs.

One of the most promising bottom-up approaches in nanoelectronics is to assemble 7i-conjugated molecules to build nano-sized electronic and opto-electronic devices in the 5-100 nm length scale. This field of research, called supramolecular electronics, bridges the gap between molecular electronics and bulk plastic electronics. In this contest, the design and preparation of nanowires are of considerable interest for the development of nano-electronic devices such as nanosized transistors, sensors, logic gates, LEDs, and photovoltaic devices. 

Fig. 1 Design principle ofYES logic gates with luminescence output and chemical input accordingto photoinduced electron transfer (PET) concepts.

Another way of designing NOT logic gates is to arrange PET involving the input guest species (Figure 3). Examples from the supramolecular era can be illustrated from publications by Czarnik and Fabbrizzi, with 3 32,33 and 4, 34 35 respectively. 

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