Electroactive Nanotubes from π-Conjugated Discotic Molecules

Abstract

Self-assembly of ³-conjugated molecules is attractive for construction of well-defined, nanometer-scale electroactive materials. This account describes our developments on self-assembled nanotubes from Gemini-shaped hexa-peri-hexabenzocoronenes (HBCs). At first, detailed molecular arrangement in the nanotube is presented, which is perfectly revealed by a synchrotron radiation X-ray diffraction analysis of a macroscopic fiber consisting of highly aligned HBC nanotubes. Next, electroconductive properties of the HBC nanotubes are investigated. By means of direct current and noncontact methods, anisotropic charge-transport properties in the nanotubes are confirmed. The effect of the surface oligoether chains on intertubular conduction is also examined by field-effect transistor measurements. Finally, optoelectronic applications are developed by constructing newly designed nanotubes. These nanotubes possess a coaxial configuration, where an electron-donating graphitic bilayer of ³-stacked HBC arrays is laminated by an electronaccepting molecular layer. Due to the molecular-layer donor/acceptor heterojunction, the nanotubes exhibit remarkable photoconduction and photovoltaic outputs. Furthermore, the optoelectronic properties are modulated by changing the density of electron acceptors on the nanotube surfaces by coassembly of multiple components or utilizing photochromism. These results will advance to electronic and optoelectronic applications of supramolecular nanomaterials.

Soft-Matter Nanotubes: A Platform for Diverse Functions and Applications

“…Not even the SMNT systems, such as AZNTs, ,, can achieve such stable reversibility and rich mobility. Light harvesting, ,, photoconductivity, ,,− and energy migration ,,,,, are typical physical functions characteristic of discrete RFBMNTs. Considering the homogeneous dimensions, specific chemical and physical functions, and the possibility for interlinking of heterogeneous pair of nanotubes, the RFBMNTs can be expected as highly smart nanomachines in every fields.…”

“…It is notable that most of physical functions, including ferroelectric, , piezoelectric, − nonlinear optical effect, ,− energy storage, , energy migration, − , photoconductivity, , and quantum confinement, ,, are manifested with the whole structures of FFNTs prepared from diphenylalanine (FF) as a molecular building block [Figure e]. Mechanical reinforcement, in which SMNTs act as incorporating fillers, − fiber mat, or additives in polymer electrolyte, is another example of the utilization of whole tube structures.…”

“…Among them, RFBMNTs self-assembled from amphiphilic, polycyclic aromatic hydrocarbons , are of particular interest regarding “all-in-one” photovoltaic nanomaterials (Figure ). , Saeki and co-workers conducted detailed kinetic studies on coassembled RFBMNTs consisting of gemini-shaped hexa- peri -hexabenzocoronene (HBC) derivatives by using flash-photolysis time-resolved microwave conductivity (FP-TRMC) technique and transient absorption spectroscopy . The obtained photoconductive RFBMNT is characterized by the coaxial structure, in which a hole-transporting layer of π-stacked HBC molecules is laminated by an electron-transporting layer of trinitrofluorenone (TNF).…”

The Chiral Separation Effect in quenched finite-density QCD

“…Previous lattice studies looked at the infrared values of the anomalous transport coefficients for the CME [26,27] and the Chiral Vortical Effect (CVE) [28,29]. These studies found a significant suppression of the CME and the CVE at both low and high temperatures, conflicting with expectations based on the hydrodynamic approximation.…”

“…At least at high temperatures the thermodynamic consistency arguments fixing the anomalous transport coefficients within this approximation should be valid [30,31]. It is possible that the origin of this discrepancy lies in the use of a naively discretised non-conserved vector current [26,27] and energy-momentum tensor [28,29]. Moreover, the simulations in [26,27] were performed with non-chiral Wilson-Dirac lattice fermions.…”