Molecular electronic properties of fused rigid porphyrin-oligomer molecular wires

✍ Scribed by J.R. Reimers; T.X. Lü; M.J. Crossley; N.S. Hush

• Book ID: 103036264
• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 512 KB
• Volume: 256
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(96)00435-6

✦ Synopsis

Porphyrin-derived materials may be linked together by fusion to rigid coplanar aromatic bridges such as substituted anthracenes to form linear or branched oligomers. Here, we consider linear oligomers of free-base porphyrin and meso-tetra-aryl derivatives, such as the tetramer. Previously, a number of semi-empirical quantum-chemical methods have been used to determine the geometries and electronic structures of the ground and excited electronic states. Here, the inter-ring coupling responsible for electron or hole conduction is discussed as a function of oligomer size and the predicted molecular-wire characteristics outlined. Comparisons with properties of other linear molecular wires are summarized, and possibilities of introducing switching capacity are indicated. It should be noted that the edge-to-edge length of the tetramer is ca. 56 ]k, sufficient for trans-membrane spanning, while the length of the octamer, ca. 110 A, is sufficient for nano-electrode spanning.