To transduce DNA drug effectively for Affective area, DNA bundling technique was developed using naphthalene diimide having two adamantane (NDI-Ad) and benzene derivatives carrying two β-cyclodextrins (bis-β-CD). NDIAd bound to double stranded DNA with threading intercalation mode with 106 M-1 order of binding constant. Gel electrophoretogram of the mixture between supercoiling plasmid pBR322 (4361 bp) in the absence or presence of NDI- Ada and the bis-β-CD showed the retarded DNA bands only in the presence of NDI- Ada and bis-β-CD. These results suggested that supercoiling plasmid aggregates by the DNA bundling through the host-gest interaction between adamantane and β-CD.
Palladium (Pd) is often substituted with the central gold (Au) atom of the icosahedral Au13 core of Aun clusters. Therefore, normally, two Au atoms are replaced by Pd atoms for the cluster having the two icosahedral Au13 cores. However, in this work, we have succeeded in isolating [Au24Pd(SC2H4Ph)5(PPh3)10Cl2]Cl in which only one Au atom was replaced by a Pd atom. Thus, this cluster has hetero-biicosahedral core composed of Au13 and Au12Pd. Such a replacement was found to change the electronic structure of the cluster.
Aluminum carbide cluster anions AlnC2 – (n = 5–13) were observed as the most dominant products in gas-phase reactions of laser-ablated Aln – with organic molecules, such as pentane, methanol, ethanol, acetonitrile, and acetone. Density functional theory calculations predicted two possible isomeric structures for AlnC2 –: isomers in which two carbons are dissociated (type D) and novel isomers in which two carbons form an acetylide-like C2 unit. The latter isomers are further categorized into three types: the C2 unit is encapsulated within the Al cage (type I), contained in the surface of Al clusters (type S), or attached to the surface of Al clusters (type O). Size-dependent behavior of the adiabatic electron affinities of AlnC2 determined by photoelectron spectroscopy was explained in terms of polymorphism as a function of size (n): type I for n = 5–8, type D for n = 9–11, type D or O for n = 12, and type O for n = 13. The tendency in which the position of the C2 unit was shifted from inside to outside with the increase in n was ascribed to the balance between the stabilizations gained by forming the Al–C bonds and the Al–Al bonds.
Plasmonic photoelectric conversion system which consists of wide energy band gap semiconductor substrate and plasmon-active metal nano-structures is one of the promising choices for the efficient use of light energy. In this study, we have carried out the plasmon induced oxidative polymerization of the conductive polymer for the visualization of the reaction active site. Through the various attempts, the detail charge transfer process has been successfully revealed. One of the important information was that we have determined the absolute electrochemical potential of the excited holes from the redox potential of the monomer. In addition to these, we have also examined the detail reaction process triggered by the excitation of the higher order plasmon mode. Our new findings would be a key information for the design of the future visible light driven high-performance plasmonic photo-conversion devices.
Localized surface plasmon resonance (LSPR) which is the collective oscillation of free electrons in the metal nanoparticle is excited under the illumination of the visible/near-infrared light. With the excitation of the LSPR, the strong electromagnetic field forms in the vicinity of the metal nanoparticle, leading to the nanoscale confinement of the light energy. However, the lifetime of the plasmon excited state is relatively shorter because of the energy loss which is originated from the light absorption and scattering. Especially, the metal nanostructure with diameter of larger than 20 nm, radiative damping is crucial factor. Thus, for further improvements of plasmonic devices, suppression of light scattering is one of the very important issue. From this background, recently, two-dimensionally arranged metal nanoparticles which show the surface lattice resonance (SLR) mode has been receiving much attention due to its long lifetime of the excited state. In this study, we have tried to optimize the characteristic of SLR mode for achieving the longer lifetime of the excited state and the effective confinement of the light energy by electrochemical approach.
Oxide dispersion strengthened (ODS) alloys are one of the most exiting candidate materials for the core components of nuclear fission/fusion reactors, because of their excellent strength at high temperatures and superior resistance against radiation damage to the conventional nuclear materials. This article explains the mechanism of the formation of nano-oxide particles in the alloys, the increasing strength by the oxide particles, the resistance to the irradiation at nuclear environment and the perspective of the ODS alloys for the future nuclear safety.