Toshikazu Ono

Simple yet ubiquitous multimolecular assembly systems with color-tunable emissions are realized by cooperative electron donor-acceptor interactions, such as the boron-nitrogen (B-N) dative bond as a Lewis acid-base pair and charge transfer (CT) interactions. These are ternary-component systems consisting of a naphthalenediimide derivative (NDI), tris(pentafluorophenyl)borane (TPFB), and aromatic molecules (guest) with an NDI:TPFB:guest ratio of 1:2:2. The crystal shows guest-dependent color-tuna

Uracil is a common form of DNA damage resulting from hydrolysis of cytosine, and cellular uracil DNA glycosylases (UDG) have evolved to remove it specifically. The use of nonnatural pyrene deoxyriboside in short DNA oligomers to directly report on UDG enzymatic activity is described. The mechanism relies on the use of uracil as a strong quencher of pyrene, and enzyme repair activity can be directly imaged with bacterial cells in real time. Detailed facts of importance to specialist readers are p

Benzene, toluene, ethylbenzene, the isomers of xylene, and trimethylbenzene are harmful volatile organic compounds and pose risks to human health and the environment. However, there are currently no effective chemosensors for vapors of these compounds. A porous supramolecular host for turn-on fluorogenic and chromogenic detection of the vapors of small aromatic hydrocarbons is presented. The host was constructed from a naphthalenediimide derivative that was supramolecularly connected to tris(pen

Effects of single and repetitive stimulation of the basolateral amygdaloid nucleus (AL) on the rat hypothalamic ventromedial nucleus (VMH) activity were investigated. Extracellular single unit discharges and evoked potentials were recorded in the VMH and stria terminalis using microelectrodes. Three effects of AL stimulation on the VMH were observed: exitation, inhibition, and disinhibition. Disinhibition may, in fact, be inhibition of inhibitory interneurons within the VMH. Finally, a tentative

A series of acid–base complexes reveal Δp<italic>K</italic>_a value and the crystalline environment determine the extent of proton transfer, which governs the intramolecular charge-transfer (ICT) strength of the complexes and tunes the photoluminescence properties.

We report the development of simple fluorogenic probes that report on the activity of both bacterial and mammalian uracil-DNA glycosylase (UDG) enzymes. The probes are built from short, modified single-stranded oligonucleotides containing natural and unnatural bases. The combination of multiple fluorescent pyrene and/or quinacridone nucleobases yields fluorescence at 480 and 540 nm (excitation 340 nm), with large Stokes shifts of 140-200 nm, considerably greater than previous probes. They are st

Oil spills and other industrial chemical leaks to natural environments can cause long-term impact on ecosystems, and the use of polymer-based absorbent materials for such media is a promising technique for cleaning up contaminated sites. Here, we prepared a set of poly(octadecyl acrylate)-based lipophilic polyelectrolyte gels bearing tetraalkylammonium tetrakis(3,5-bis(trifluoromethyl)phenyl) borate (TFPB) with different contents of the ionic groups from 1.0 mol% (EG18(1%)) to 10 mol% (EG18(10%)

The gram-scale production of porphycene derivatives is reported. This has been achieved by acid-catalyzed ring closure of an <i>E</i>/<i>Z</i>-mixture of 5,6-diaryldipyrroethenes, resulting in the formation of <i>meso</i>-tetraarylporphycenes in yields of up to 80%. <i>E</i>/<i>Z</i>-isomerization of the 5,6-diaryldipyrroethenes under acidic conditions was key to proceed the effective macrocyclization.

Molecular design of superabsorbent materials for organic solvents has attracted much attention due to their superior applications for the removal of hazardous leakages or spillages of volatile organic compounds (VOCs) and waste oils. One approach for preparing such soft matter is loosely crosslinked lipophilic polyelectrolytes. Here, we demonstrate the counter anion effect for superabsorbency for various organic solvents in a series of poly(octadecyl acrylate)-based lipophilic polyelectrolyte ge

Vapochromic materials, which change color and luminescence when exposed to specific vapors and gases, have attracted considerable attention in recent years owing to their potential applications in a wide range of fields such as chemical sensors and environmental monitors. Although the mechanism of vapochromism is still unclear, several studies have elucidated it from the viewpoint of crystal engineering. In this mini-review, we investigate recent advances in the vapochromism of organic crystals.

Polyelectrolytes are ubiquitous materials, and their unique properties originate from dissociation of ionic groups to the small number of macromolecular ions and the large number of small counterions. They have been exploited only in water or high-dielectric media and scarcely in nonpolar ones (ε < 10). Herein, we demonstrate that poly(octadecyl acrylate) bearing tetraalkylammonium tetraarylborate as ionic groups behaves as a polyelectrolyte in the common nonpolar organic solvents such as chloro

Two novel meso-dicycloalkylporphycenes, namely meso-dicyclopentyl- (Cy5Pc) and meso-dicyclohexylporphycenes (Cy6Pc) are synthesized for the first time in porphycene chemistry. We use intermolecular oxidative coupling of 5,6-dicycloalkydipyrroethenes mediated by hypervalent iodine(iii) reagents. The solution fluorescence maxima of Cy5Pc are more than 400 times as intense as that of Cy6Pc. The results suggested that photoluminescence switching is achieved through the ring strain perturbation of th

Discontinuous volume changes of lipophilic polyelectrolyte gels in non-polar organic solvent mixtures are demonstrated towards the construction of stimuli-sensitive materials in media other than water.

Inclusion crystals were effectively formed from a simple naphthalenediimide derivative with toluene, 4-fluorotoluene, and p-xylene by the aid of cooperative intermolecular interactions, such as charge-transfer interactions and inclusion phenomena. The crystals showed intense guest-dependent solid-state emission based on ground state CT complexes between naphthalenediimide and small aromatic guests.