title: Polymetallated porphyrin ultrathin films as transducing elements for molecular devices and logic gates.
abstract: Meso-tetrapyridylporphyrins peripherally coordinated to four ruthenium complexes, such as [Ru(bpy)2Cl] and [Ru(5-ClPhen)2Cl] (bpy = 2,2'-bipyridine; Phen = 1,10-phenanthroline), provide a versatile class of molecular materials in which the complexes act as co-factors, inducing electronic effects and acting as electron-transfer relays and electron pools or sinks, depending upon their oxidation state. These cationic porphyrins can be assembled into thin films by conventional methods, or into organized layer-by-layer structures by combining with negatively charged tetrasulfonated porphyrins or phthalocyanines. Their electrocatalytic and photoelectrochemical properties have been successfully exploited in chemical sensors. Their usefulness in molecular logic gates are being demonstrated by using modified transparent conducting electrodes in miniaturized flow injection cells. In such designs, the chemical, electrochemical, and light inputs can be readily combined to perform the basic logic functions, such as AND, OR, and NOT, for molecular computing.
authors.affiliation: Instituto de Química, Universidade de São Paulo, Caixa Postal 26077, CEP 05513-970, Sao Paulo, SP, Brazil.
authors.forename: Herbert
authors.initials: H
authors.lastname: Winnischofer
authors.forename: Henrique Eisi
authors.initials: HE
authors.lastname: Toma
authors.forename: Koiti
authors.initials: K
authors.lastname: Araki
mesh_terms: D039301:Computers, Molecular; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D008128:Logic; D008665:Metalloporphyrins / Q000737:chemistry*; D015394:Molecular Structure; D036103:Nanotechnology / Q000379:methods*; D055672:Static Electricity; D014159:Transducers
chemical_list: D008665:Metalloporphyrins