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Masateru Taniguchi

Publications and source records attributed to Masateru Taniguchi.

7 recordsLinked to original sources
PubMed2006

Photoconductive coaxial nanotubes of molecularly connected electron donor and acceptor layers.

Controlled self-assembly of a trinitrofluorenone-appended gemini-shaped amphiphilic hexabenzocoronene selectively formed nanotubes or microfibers with different photochemical properties. In these nanotubes, which are 16 nanometers in diameter and several micrometers long, a molecular layer of electron-accepting trinitrofluorenone laminates an electron-donating graphitic layer of pi-stacked hexabenzocoronene. The coaxial nanotubular structure allows photochemical generation of spatially separated charge carriers and a quick photoconductive response with a large on/off ratio greater than 10(4). In sharp contrast, the microfibers consist of a charge-transfer complex between the hexabenzocoronene and trinitrofluorenone parts and exhibit almost no photocurrent generation.

Journal Article↗
PubMed2006

Self-organized interconnect method for molecular devices.

Lack of an appropriate method for wiring molecules that have controlled functions and structures has been a barrier for the development of molecular devices. We developed an interconnect method to program three kinds of component molecules with their own functions and to wire a molecular device in a self-organized manner. By using the interconnect method we developed, we produced conductive wires and optical switching devices and have demonstrated their device functions. Our interconnect method allows us to control various molecular device characteristics by combining the three molecules.

Journal Article↗
PubMed2005

Electron-molecular-vibration coupling for small polarons in DNAs.

Within a tight-binding electron-phonon interacting model, we calculated the spectrally resolved polaron binding energy between electrons and phonons and between holes and phonons on poly(dA).poly(dT) and poly(dG).poly(dC).Poly(dA).Poly(dT) is a DNA where one single strand consists only of adenine(A) and the other single strand consists only of thymine(T), while Poly(dG).Poly(dC) is a DNA where one single strand consist only of guanine(G) and the other of cytosine(C). We found that the polaron binding energies of poly(dA).poly(dT) were larger than those of poly(dG).poly(dC), and that the polaron binding energy and the electrical conductance were strongly temperature dependent. These findings agree well with the current experimental data. We concluded that small polaron hopping occurs by a conduction mechanism on the DNA molecules examined.

Binding Sites↗
PubMed2004

Synthesis of long Poly(dG).Poly(dC) DNA using enzymatic reaction.

Non-defect Poly(dG).Poly(dC) of 500 bp (170 nm) has been synthesized by using enzymatic reactions and was characterized by its UV spectrum, showing that conjugated pi-electrons between base pairs are spread over the DNA molecule suggesting the absence of structural defects.

DNA↗
PubMed2004

Electronic structures of A- and B-type DNA crystals.

The electronic band structures and total density of states based on a density-functional theory are performed on four deoxyribonucleic acid (DNA) molecules: namely, A- and B-type DNA where a single pitch is formed by 11 and 10 base pairs, respectively, of Poly (dA) *Poly (dT) and Poly (dG) *Poly (dC). Poly (dA) *Poly (dT) is a DNA where one single strand consists only of adenine (A) and the other single strand consists only of thymine (T), while Poly (dG) *Poly (dC) is a DNA where one single strand consists only of guanine (G) and the other of cytosine (C). A- and B-Poly (dA) *Poly (dT) and A- and B-Poly (dG) *Poly (dC) DNA. Compared in the same structure, the band gap of Poly (dA) *Poly (dT) is larger than that of Poly (dG) *Poly (dC). The highest occupied molecular orbitals (HOMO's) of Poly (dA) *Poly (dT) and Poly (dG) *Poly (dC) are formed by adenine's and guanine's HOMO, respectively, regardless of the structure type. On the other hand, the lowest unoccupied molecular orbitals (LUMO's) of DNA of both types are formed by the orbitals of Na and P O4, though the LUMO's of B-Poly (dA) *Poly (dT) and B-Poly (dG) *Poly (dG) are formed by thymine's and cytosine's LUMO when the DNA-DNA distance is more than 3 nm. The minimum energy gap between the valence edge and the empty state of Na and PO4 is 0.9 eV in A-Poly (dG) *Poly (dC). The narrow bandwidth of the valence and conduction bands show that the conduction arises not from band transport but a hopping mechanism in the presence of doping.

Base Pairing↗