A5015903245- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Synthesis and Properties of Aromatic Compounds
- Luminescence and Fluorescent Materials
- Axial and Atropisomeric Chirality Synthesis
- Porphyrin and Phthalocyanine Chemistry
- Molecular Sensors and Ion Detection
- Molecular spectroscopy and chirality
- Crystallography and molecular interactions
- Carbon dioxide utilization in catalysis
- Organic Electronics and Photovoltaics
- Asymmetric Hydrogenation and Catalysis
- Photochromic and Fluorescence Chemistry
- CO2 Reduction Techniques and Catalysts
- Supramolecular Chemistry and Complexes
- Polydiacetylene-based materials and applications
- Synthetic Organic Chemistry Methods
- Conducting polymers and applications
- Phytochemistry and Biological Activities
- Supramolecular Self-Assembly in Materials
- Thin-Film Transistor Technologies
- Advanced Sensor and Energy Harvesting Materials
- Metal-Organic Frameworks: Synthesis and Applications
- Organoboron and organosilicon chemistry
- Advanced Memory and Neural Computing
Okayama University
2016-2025
Lanzhou University
2023
Pioneer (Japan)
2019
RIKEN Advanced Science Institute
2009-2018
Advanced Science Research Center
2017
RIKEN
2008-2016
Faculty (United Kingdom)
2016
Engineering (Italy)
2016
Seikei University
2012-2015
RIKEN Center for Sustainable Resource Science
2015
A series of pyrenes sandwiched by axially chiral 1,1′-binaphthyls were synthesized. Among them, (R,R)-3 possessing 2-hydroxy-3,3′-dimethylbinaphthyls exhibited solvent-dependent inversion the sign circularly polarized luminescence (CPL) without a change in emission wavelength. The (−)- and (+)-CPL detected nonpolar polar solvents, respectively, with glum values −0.012 +0.012. This switching property originates from excimer chirality caused presence or absence intermolecular hydrogen bonds...
A series of chiral cyclic dyads, axially binaphthyls linked to a 3,3′-bipyridyl, was synthesized. The dyad 2 bearing methoxy groups exhibited ON/OFF properties in circularly polarized luminescence (CPL), yielding |glum| 1.6 × 10–3 or 0 without any change fluorescence. This type CPL switch is unprecedented. Regioisomer 4 dextro/levo rotation switching ability [α]D. X-ray structures as well experimental and theoretical analyses suggested that the depended on conformational changes.
A versatile method for converting various fluorescent polycyclic aromatic hydrocarbons into circularly polarized luminescence (CPL) excimer dyes with high glum and ΦFL values is reported. This involves the functionalization of a chiral quaternaphthyl six fluorophores via ester linkages in last step synthesis. The usefulness this approach was demonstrated 1-, 2-, 4-pyrenyl, 2- 3-perylenyl, 2-anthryl dyes. Most them are first or rare examples CPL In ground state, tightly arranged by cumulative...
Reactive oxygen species (ROS) are generated in the cell through multiple mechanisms. Intracellular ROS rapidly detoxified by various enzymatic and non-enzymatic mechanisms; however, disruption of oxidant-antioxidant balance causes oxidative stress elicits damage. The induced chemotherapy is known to cause side effects patients with cancer. However, few studies have examined whether anticancer drugs induce cancer cells. Furthermore, precise mechanism which generation remains unclear. In...
A series of axially chiral peri-xanthenoxanthenes (PXXs) were synthesized from 1,1′-bi-2-naphthol without optical resolution. These are the first examples PXXs. Among them, PXX 5 with two naphthalene rings connected via a methylenedioxy bridge and axis displayed intense fluorescence (FL) circularly polarized luminescence (CPL) both in solution (ΦFL 0.72 |glum| 1.4 × 10–3) solid state 0.13 4.8 10–3). The bridged structure adjusts angle between vectors electric magnetic transition dipole...
(R,R,R)-Quaternaphthyls possessing eight and six pyrenes (compounds 4 3) displayed intense excimer-CPL. The glum values in solution the solid state were +0.034-0.037 +0.0053-0.0056, respectively. of 3 indistinguishable, indicating that assumed same conformation, even excited states. CPL was caused by conformationally rigid arranged via cumulative steric effects along quaternaphthyl axis.
Hemisquaramide tweezers, a new family of H-bond donor organocatalysts, are reported. The catalysts could be synthesized within two steps. Among them, H8-binaphthyl-linked hemisquaramide 7 markedly accelerated the synthesis cyclic carbonates from epoxides and CO2. reactions proceeded well under mild solvent-free conditions. Kinetic resolution was also achieved at −20 °C (s = 3.0). adjustable bite angle orientation NH groups important for high activity.
Abstract A series of axially chiral 1,1′‐binaphthyls with trialkylsiloxy (OSiR 3 ) groups were synthesized. Among them, 1 a – c possessing OSiR at the 7,7′‐positions and methyl 2,2′‐positions liquids room temperature, neat showed circularly polarized luminescence (CPL) (R=Bu; Φ fl,liquid =0.21, | g lum,liquid |=1.6×10 −3 ). The value is highest pure liquids. These compounds remained liquid over broad range temperatures, down to −50 °C. Time‐dependent DFT calculations indicated that in...
A series of D2 -symmetric macrocycles composed alternately linked pyrene and binaphthyl moieties (binaphthyl-bridged pyrenophanes) have been synthesized. Among them, a pyrenophane possessing ether linkers at the 2,7-positions pyrenes exhibited intense circularly polarized luminescence (CPL) with |glum | value 0.053. This is by far highest for excimers was not sensitive to temperature, solvent, or concentration. The CPL originated from twisting excimer, (R)-binaphthyl producing left-handed...
Abstract D 2 ‐symmetric ( R )‐binaphthyl‐bridged pyrenophanes containing thioether bonds were synthesized. The exhibited the temperature‐induced sign inversion of circularly polarized luminescence (CPL) while maintaining emission wavelength and reversibility. Δ g lum value reached 0.02, FL quenching by heat was negligible. CPL originates from intramolecular excimer chirality associated with excitation dynamics. two pyrenes form a kinetically trapped left‐handed twist at low temperatures,...
Asymmetrie durch Ionenpaare: Auf den Zusatz chiraler Ammoniumchloride und -bromide hin entstehen in Lösungen pyrrolbasierter π-konjugierter linearer Oligomere helikale Strukturen, wobei die Bildung diastereomerer Ionenpaare mit chiralen Kationen für eine asymmetrische Induktion sorgt (siehe Bild). Diese zeigen einen Circulardichroismus (CD) stark circular polarisierte Lumineszenz (CPL) glum-Werten über 0.1.
Using a bottom-up method, we prepared series of oligonaphthofurans composed alternating naphthalene rings and furan rings. The largest compound (compound 25) contained 8 units 7 units. DFT calculations revealed that these compounds were fan-shaped molecules each ring was oriented in an alternate mountain-valley fold conformation because steric repulsion by the hydrogens at peri-positions. We investigated optical properties derived from their sequences. As number aromatic increased, peaks...
Unique self-assembled macrocyclic multinuclear ZnII and NiII complexes with binaphthyl-bipyridyl ligands (L) were synthesized. X-ray analysis revealed that these consisted of an outer ring (Zn3 L3 or Ni3 ) inner core (Zn2 Ni). In the complex, Zn2 part rotated rapidly inside in solution on NMR timescale. These exhibited dual catalytic activities for CO2 fixations: synthesis cyclic carbonates from epoxides temperature-switched N-formylation/N-methylation amines hydrosilane.
Abstract A series of oligonaphthodioxepins was synthesized, revealing a helically arranged octamer, ( R , )‐ 3 which showed intense circularly polarized luminescence (CPL) both in solution and the solid state. The fluorescence quantum yields (Φ FL ) state were 0.90 0.22, respectively, g lum values +2.2×10 −3 +7.0×10 respectively. This is one highest solid‐state CPL yet reported. high Φ due to rigidity, as well fact that non‐planar molecule. Moreover, highly stable chemically stereochemically.
Oriented salts from planar charged species were prepared by combining positively and negatively receptor-anion complexes with similar geometries using dicationic electronically neutral π-conjugated receptors. Phenylene- or pyrimidine-bridged bis(imidazolium) anion receptors formed monocationic receptor-Cl(-) that accompanied a free Cl(-). This Cl(-) was subsequently captured pyrrole-based to form complexes. The ion pair of the resulting could produce supramolecular octane gel, adopting...
Among chiral macrocycles 1 synthesized, 1m with the 3,5-bis(trifluoromethyl)phenylethynyl group was best organocatalyst for enantioselective synthesis of cyclic carbonates from disubstituted or monosubstituted epoxides and CO2. The X-ray crystal structure revealed a well-defined cavity multiple hydrogen-bonding sites that is suitable activation epoxides. A catalytic cycle proposed supported by DFT calculations.
Doubly (R)-binaphthyl-strapped porphyrins with methylene chains were synthesized. The CD spectra showed the positive Cotton effect around Soret bands, and several CPL. In addition, we found that chiral applicable to kinetic resolution of epoxide CO2.
Chiral carbazole-based BODIPYs with a binaphthyl unit were synthesized via an Al-mediated reaction. Et2AlCl was found to be convenient reagent for the reaction give chiral in high yields. It has been shown first time that these show circularly polarized luminescence (CPL) both solution and solid state.
Hexameric and tetrameric porphyrin nanorings, Z6·T6 Z4·T4, were synthesized in 53% 14% yields, respectively, by the Sonogashira-type self-oligomerization of monomer 1 using hexadentate template T6 tetrapyridylporphyrin T4. Template-free nanorings Z6 Z4 also prepared. The femtosecond transient absorption measurements revealed fast excitation energy hopping (EEH) along these with rates 2–5 ps. Treatment chiral CT6 gave Z6·CT6 showing circular dichroism (CD) circularly polarized luminescence...
This paper reports the formation and properties of covalently strapped double helices bidipyrrin–ZnII complexes, where four dipyrrin chromophores interact with one another by strong exciton coupling. Thorough experimental examination, UV/vis, CD 1H NMR spectra, theoretical studies suggest existence two modes helix depending on dihedral angles between units at pyrrole α–α bond. In fact, changes were observed according to lengths straps as well temperatures.
<italic>meso</italic>-Octamethylcalix[4]pyrrole worked as an organocatalyst for the conversion of epoxides and CO<sub>2</sub> into cyclic carbonates under solvent-free conditions.
Recent progress in homogeneous catalysis with macrocyclic multinuclear metal complexes (categories A–C) is overviewed.
Axially chiral binaphthyls and quaternaphthyls possessing two kinds of fluorophores were synthesized. In the excited state, formed a twisted exciplex exhibited CPL. This study gave us named chirality rule.