Biased Bowl-Direction of Monofluorosumanene in the Solid State

Yakiyama Y., Li M., Zhou D., et al. Biased Bowl-Direction of Monofluorosumanene in the Solid State. Journal of the American Chemical Society 146, 5224 (2024); https://doi.org/10.1021/jacs.3c11311.A new curved π-conjugated molecule 1-fluorosumanene (1) was designed and synthesized that possesses one fluorine atom on the benzylic carbon of sumanene. This compound can exhibit bowl inversion in solution, leading to the formation of two diastereomers, 1endo and 1exo, with different dipole moments. Experimental and theoretical investigation revealed an energetical relationship among 1exo, 1endo, and solvent to realize the various endo:exo ratios in the single crystals of 1 depending on the crystallization solvent. Significantly, the molecular dynamics (MD) simulations revealed that 1exo positively worked for the elongation of the stacking structure and the final endo:exo ratio was affected by the relative stability difference between 1endo and 1exo derived by solvation. Such an arrangeable endo:exo ratio of 1 realized the preparation of unique materials showing a different dielectric response from the same molecule 1 just by changing the crystallization solvent

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2, 2'-bi-1H-imidazole系の多段階陽子移動と電子移動性に関する研究

本文データは平成22年度国立国会図書館の学位論文(博士)のデジタル化実施により作成された画像ファイルを基にpdf変換したものである京都大学0048新制・課程博士博士(理学)甲第6682号理博第1817号新制||理||990(附属図書館)UT51-97-H66京都大学大学院理学研究科化学専攻(主査)教授 斎藤 軍治, 助教授 浅見 耕司, 助教授 矢持 秀起学位規則第4条第1項該当Doctor of ScienceKyoto UniversityDFA

Organic nanodots of a cation radical salt of amphiphilic bis-TTF annulated macrocycle

Organic nanodots of a cation radical salt of amphiphilic bis-TTF annulated macrocycle derivative were fabricated on mica surface by cast technique. The nanodots, whose diameter and height of nanodots depended on the surface positions, were arranged on mica surface during the solvent evaporation process

Orthogonality of Jahn-Teller axes in a dinuclear Cu(II) complex bridged by one F- anion

The dinuclear Cu(II) complex bridged by a single F- anion has orthogonal Jahn-Teller axes, which induce a ferromagnetic interaction between the intramolecular Cu(II) ions

Electron transport in a gold nanoparticle assembly structure stabilized by a physisorbed porphyrin derivative

Gold nanoparticles stabilized by meso-5,10,15,20-tetrakis(2-thienyl)porphyrin (2T) via physisorption (2T-AuNP) were synthesized, and the electronic transport of assemblies of these films was studied. The adsorption mechanism of 2T on gold nanoparticles was examined using UV-vis-NIR, IR, Raman, and H-1-NMR spectroscopy, which showed no evidence of any covalent bonding between 2T and the gold nanoparticles. In temperature-dependent resistivity measurements, a crossover from thermally assisted hopping to Efros-Shklovskii-type variable-range hopping (ES-VRH) was observed around 50 K on decreasing the temperature. At higher temperatures, the 2T-AuNP assembly structure followed an Arrhenius plot (E-A=15 meV) with ohmic I-V characteristics at each measurement point. On the other hand, the activation energy at lower temperatures decreased nonlinearly in a T-1 plot, and the logarithm of the resistance obeyed a T-1/2 law, corresponding to an ES-VRH mechanism, which is predicted for disordered materials as a variable-range hopping mechanism influenced by strong Coulomb interactions. ES-VRH behavior has been observed previously in saturated molecule/gold nanoparticle assemblies and was confirmed in our 2T-AuNP assembly. Electronically active conjugated molecules were successfully incorporated between the nanoparticles, keeping the electronic structure of the gold nanoparticle and 2T moieties isolated from each other

Temperature dependence of band gap energies of GaAsN alloys

The temperature dependence of band gap energies of GaAsN alloys was studied with absorption measurements. As the N concentration in GaAsN increased, the temperature dependence of the band gap energy was clearly reduced in comparison with that of GaAs. The redshift of the absorption edge in GaAsN for the temperature increase from 25 to 297 K was reduced to 60% of that of GaAs for the N concentration larger than ~1%. The differential temperature coefficient of the energy gap at room temperature was also reduced to 70% of that of GaAs. The main factor for this reduced temperature dependence in GaAsN was attributed to the transition from band-like states to nitrogen-related localized states with detailed studies of the temperature-induced shift of the absorption edge

Crystal structure and physical properties of a dithiolene complex crystal with adamantane supramolecular rotator

Supramolecular cation salt of adamantane rotator with a dithiolene complex, (fluoroadamantylammonium(+))([18]-crown-6)[Ni(dmit)(2)](-) (1) was synthesized. The fluorine atom of the adamantane unit showed a large thermal factor elongated latitudinally, suggesting molecular rotation in the solid state. Crystal 1 exhibited a large dielectric response by applying an AC field along the a axis