Molecular Electronic s in Nanosciences

Hiroshi Nishihara

Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.


A goal of molecular electronics which is one of the most imperative targets in nanoscience is to control electron conduction in molecular networks by combining appropriate molecular units. Construction of molecular networks comprising highly conducting molecular wires1 and introduction of external stimuli responsive molecular units2 can lead to intelligent molecular circuits. To realize these molecular circuits, evaluat ion of the total performance of molecular wires is necessary, and thus the electron conduction properties of internal molecular segments as well as the resistivity at the electrode - molecular wire junction must be elucidated. Here present two topics concerning molecular electronics. The first topic concerns the interfacial bottom-up synthesis of p -conjugatged redox molecular wires of metal complex oligomers 3. In this method, molecular wire structures with the controlled number of complex units and designed shapes and hetero-metal sequence s can be built on the surface. We have analyzed the electron transport mechanism and kinetics for the redox reaction of the films of linear and branched oligomer wires , long-range electron-transport abilities , and surface junction effects. The second topic is development of bio-photosensors composed of cyanobacterial photosystem I (PSI) and a molecular wire4. We have succeeded in photosensing using a combination of PSI, VK1-like molecular wire, Au nanoparticle, and field-effect transistor (FET), and further developed related photoelectronic conversion systems.



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[2] S. Kume and H. Nishihara, Struct. Bond.2007, 123, 79. S. Kume and H. Nishihara, Dalton Transactions (Perspective), 2008, 3260 . K . Namiki et al. , New J. Chem. 2011 , 35 , 2146.

[3] Y. Nishimori, et al., Chem. Asian J. 2007, 2, 367. Y. Nishimori, et al., Chem. Asian J. 2009 , 4, 1361 T. Kurita, et al., J. Am. Ch e m. Soc. 2010 , 132 , 4524. K . Uchida et al. , J. Am. Chem. Soc. 2011 , 133, 9239 . H. Maeda et al., Chem. Commun.2011, 47, 8644.

[4] N. Terasaki et al., Biochim. Biophys. Acta , Bioenerg.2007, 1767, 653. M. Nakai et al., Angew. Chem. Int. Ed.2008, 47. 6699. N. Terasaki et al., Angew. Chem. Int. Ed.2009, 48, 1613. M. Miyachi et al. J. Naosci. Nanotech. 2009 , 9, 1722. M. Miyachi et al. Chem. Commun.2010, 46 , 2557 .