Formation of a Molecular Wire Using the Chemically Adsorbed Monomolecular Layer Having Pyrrolyl Groups

Kazufumi Ogawa,Shin-Ichi Yamamoto,Tadashi Ohtake,Norihisa Mino

doi:10.1155/2011/560830

Kazufumi Ogawa, Shin-Ichi Yamamoto + Show 2 more

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https://doi.org/10.1155/2011/560830

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Abstract

A molecular wire containing polypyrrolyl conjugate bonds has been prepared by a chemical adsorption technique using 1,1,1-trichloro-12-pyrrolyl-1-siladodecane (PNN) and an electrooxidative polymerization technique, and the conductivity of the molecular wire without any dopant has been measured by using AFM/STM at room temperature. When sample dimension measured was about 0.3 nm (thickness of the conductive portion in the PNN monomolecular layer) ×100 μm (the average width of an electric path) ×2 mm (the distance between Pt positive electrode and the AFM tip covered with Au), the conductivity of the polymerized PNN molecular wire at room temperature was larger than 1.6 × 105 S/cm both in an atmosphere and in a vacuum chamber of 10−5 Torr. The activation energy obtained by Arrhenius' plots was almost zero in the temperature range between 320 and 450 K.

Highlights

There have been numerous investigations into the preparation of conductive polymers and those electricproperties, the conductivity of the conjugate bonds itself has not been measured at present.W
We tried to measure conductivity at the electric path (three points on the polymerized portion of the PNN monomolecular layer indicated by cross-marks on the images D2, E2, and F2 in Figure 7(b)) using the atomic force microscope (AFM) tip covered with Au in an atmosphere at room temperature
This indicates that the electric resistance of the electric path is smaller than the contact resistance and another contact resistance and the circuit resistance of our setup

Summary

Introduction

There have been numerous investigations into the preparation of conductive polymers and those electricproperties, the conductivity of the conjugate bonds itself has not been measured at present.W. There have been numerous investigations into the preparation of conductive polymers and those electricproperties, the conductivity of the conjugate bonds itself has not been measured at present. Little reported about forty years ago from a realistic estimation of the matrix elements and density of states in certain organic polymers having a long unsaturated polyene chain that superconductivity should occur even at temperatures well above the room temperature [1]. The superconductivity has not been confirmed yet at room temperatures on the organic polymer. Chiang et al reported that the highest room-temperature results were obtained by doping cis-(CH)x with AsF6 to yield cis- CH(AsF5)0.14 x with σ(300 K) = 560 Ω−1cm−1. The conductivity of the polyacetylenic conjugated bonds itself might no been measured directly

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Conclusion