The University of Osaka · 재료과학
Yumi Yakiyama 교수의 연구실은 곡면 π-공명 구조를 가진 소마네인 유도체를 핵심으로 하여, 고체 상태에서의 분자 운동, 다공성 금속-유기 프레임워크, 그리고 전기적· dielectric 특성을 가진 신소재를 설계하고 있습니다. 특히, 분자 구조의 비대칭성과 유기 리간드의 다기능성에 기반한 정밀한 상호작용 제어를 통해 나노스케일의 기능성 물질을 창출합니다. 이는 에너지 저장, 전자소자, 스마트 재료 등 응용 분야로의 전환 가능성을 지닌 연구입니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Two sumanene-based porous coordination networks were successfully prepared by the complexation of hexapyridylsumanene with Zn(NO<sub>3</sub>)<sub>2</sub>·6H<sub>2</sub>O or Cd(NO<sub>3</sub>)<sub>2</sub>·4H<sub>2</sub>O. X-ray single crystal analysis unambiguously revealed that the curved structure of the central sumanene skeleton of the ligand resulted in the formation of a large confined space with a small aperture size. In the Zn<sup>2+</sup> network, the beltlike trimer units were connected
A tripyridyl multi-interactive ligand TPHAP is prepared by a one-pot reaction on a gram scale. Network formation of Co(ii) with TPHAP(-) gave kinetic and thermally more stable products. The kinetic network showed an unprecedented dynamic network transformation on the crystal surface by a ligand exchange reaction.
A large dipole moment of 1,1-difluorosumanene realized a 120° in-plane pendulum motion in the stacking columns at above 380 K. This dynamic motion in the solid state enabled anisotropic dielectric relaxation induced by the external electric field.
A new curved π-conjugated molecule 1-fluorosumanene (<b>1</b>) 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, <b>1</b><sub><b><i>endo</i></b></sub> and <b>1</b><sub><b><i>exo</i></b></sub>, with different dipole moments. Experimental and theoretical investigation revealed an energetical relationship among <b>1</b><sub><b><i>exo</i></b></sub>, <b>
A series of co-crystals of 1,1-difluorosumanene (F2-Sum) and sumanene (Sum) were obtained. The co-crystallization successfully tuned their structural and physical properties, especially the dielectric response, without any chemical modifications. X-ray analyses and theoretical calculations revealed the reduction of intermolecular interaction energy due to the presence of F2-Sum.
Abstract Complex formation of quaterimidazole with Fe II , Co II , and Ni II yielded dinuclear triple helicates in the solution state by the self‐assembling ability of the ligand based on the strong chelating coordination bonds. Crystallization of the Co II complex from aqueous solution afforded the Co III complex with a triple‐helical structure. X‐ray crystal structure analyses revealed that the helicates are linked through N–H ··· X hydrogen bonds with counteranions and solvent molecules to fo
A compact, low-power microchip laser system is utilized for pulse laser ablation in liquids, and the impact of solution viscosity on the efficiency of gold nanoparticle ablation in PVP solutions is explored.
Interconvertible molecular crystals 1<sub>close</sub> and 1<sub>open</sub> composed of 4-pyridyl-1,3-indanedione dimer 1 were selectively obtained. Thermal removal of solvent molecules in 1<sub>open</sub> afforded 1<sub>close</sub>. Further dipping of 1<sub>close</sub> in a specific solvent reproduced 1<sub>open</sub>. No crystallinity loss was observed even though both processes involved a drastic change of molecular packing arrangements.
Abstract Organic crystalline dielectric materials are attractive target in the field of materials chemistry. In their designing strategy, the molecular motion induced by the external dielectric field is required to maximize the polarization effect in the materials to realize a large dielectric constant. Especially, the molecular motion of curved-π aromatics such as C 60 and their supramolecular complexes are the known to show characteristic smoothness in the solid state. In this context, we focu
Ammonium and sodium salts (ion pairs) of a multi-interactive tri(4-pyridyl)hexaazaphenalenyl anion (TPHAP(-)) showed completely different ion-conductive properties depending on the crystal structure. TPHAP columnar crystals showed a high conductivity of 10(-3) S cm(-1) while retaining their structures even under humid conditions, whereas TPHAP dimer crystals exhibited a conductivity of ∼10(-5) S cm(-1) with crystallinity deterioration. The main unit structures induced by multi-interactivity real
Ru( ii ) complexes with sumanene-functionalised terpyridine ligands exhibited dual emission via the TICT mechanism due to the relatively easy rotation around the sumanene–terpyridine bond axis. They also showed selective Li + sensing ability.
We have observed the generation of sumanenylidene (2), a divalent, neutral-carbon species at the benzylic position of sumanene (1). We also clarified both experimentally and theoretically that the ground state of compound 2 was a triplet state and that its singlet-triplet energy gap (ΔE<sub>ST</sub> ) was similar to that in fluorenylidene. The curved structure of compound 2 led to slightly better spin delocalization over the two adjacent aromatic rings than in planar systems, because of the unpa
Crystalline powders self-assembled from interactive discrete molecules reversibly transformed from a porous structure to a 2D one with a nanometer-thick H2O layer by hydration/dehydration. Multi-point weak intermolecular interactions contributed to maintenance of each phase. This structure transformation induced a humidity-dependent ion conductivity change from insulator to 3.4 × 10(-3) S cm(-1).
