Synthesis and photophysical properties of dinaphtho[2,3-b:2′,3′-i]dihydrophenazine derivatives

A dinaphtho[2,3-b:2′,3′-i]dihydrophenazine (DNP) derivative was synthesized by Buchwald-Hartwig cross-coupling, and its electronic spectrum was compared with that of dinaphtho[b,i]dihydrophenazine-5,18-dione (DNP-dione) as an anthraquinone analog. An absorption band of DNP is attributed to extension of π-conjugation over the entire molecule via the N atom. DNP-dione showed a broad absorption band in the range 450–490?nm due to intramolecular charge-transfer interactions. Additionally, the absolute fluorescence quantum yield of DNP was larger than that of DNP-dione. DNP-dione exhibited reversible oxidation peaks and a similar oxidation potential to DNP, since there are very weak electronic interactions between the anthracene and anthraquinone units across the N atoms with the 4-octyloxyphenyl substituent.     

Ti-sapphire femtosecond pulse pumped laser emission from all-plastic organic waveguide with distributed feedback resonator

We demonstrated the spectrally narrowed laser emission from all-plastic organic waveguide with the distributed feedback (DFB) resonator pumped by Ti-sapphire femtosecond laser. We fabricated the DFB resonator on a surface of a photoresist polymer using an interference of laser beams. All-plastic waveguide with organic dyes dispersed in poly(N-vinylcarbazole) and polystyrene matrix was spin-coated on a DFB resonator. Very narrow full width at half maximum (FWHM) of 0.15 nm in emission wavelength was observed, whereas an excitation laser of Ti-sapphire femtosecond laser has broad FWHM of 14 nm.     

Fundamental Relation Between Entropy Production and Heat Current

Journal of Statistical Physics - We investigate the fundamental relation between entropy production rate and the speed of energy exchange between a system and baths in classical Markov processes....     

RhIII-Catalyzed Double Dehydrogenative Coupling of Free 1-Naphthylamines with α,β-Unsaturated Esters

The Rh^III-catalyzed, consecutive double C−H oxidative coupling of free 1-naphthylamine and α,β-unsaturated esters through C−H/C−H and C−H/N−H bonds is reported. The one step reaction leads to the formation of biologically important alkylidene-1,2-dihydrobenzo[cd]indoles scaffolds. This efficient process is much more synthetically convenient and useful than others because the starting materials, such as 1-naphthylamine derivatives are readily available and the free amine serves as a directing group.     

Synthesis of conjugated polymers possessing diketopyrrolopyrrole units bearing phenyl,pyridyl, and thiazolyl groups by direct arylation polycondensation: Effects of aromatic groups in DPP on physical properties

Conjugated polymers containing phenyl‐, pyridyl‐, and thiazolyl‐flanked diketopyrrolopyrrole (DPP) were synthesized by direct arylation polycondensation of 3,4‐ethylenedioxythiophene derivatives and dibrominated DPP‐based monomers, in order to probe the effects of the aromatic groups in the DPP units on the absorption property, energy level, and crystallinity. A polymer possessing thiazolyl‐flanked DPP units was found to display long‐wavelength absorption properties and higher crystallinity than the polymers bearing phenyl‐ and pyridyl‐flanked DPP units. These features of the thiazolyl‐based polymer were afforded by its coplanar structure of the main chain. The synthesized polymers showed semiconducting properties in organic field effect transistors and organic photovoltaics. Direct arylation polycondensation is an efficient synthetic method that affords a series of DPP‐based polymers in a simple fashion and, thus, helping in a comprehensive understanding on the relationship between the aromatic groups in DPP units and their physical properties. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2337–2345     

Synthesis of Organosilyl-Functionalized Cage-Type Germanoxanes Containing Fluoride Ions

Eight corners of a double-four ring cage-type germanoxane, containing a fluoride ion, were successfully silylated by the combination of chlorosilanes and silazanes. Three different silyl groups, trimethylsilyl, dimethylsilyl, and dimethylvinylsilyl, were attached on the corners of germanoxane cage. The solubility and reactivity of the cage modified with dimethylvinylsilyl groups were significantly increased, allowing for further reaction. Hydrosilylation reaction between dimethylvinylsilylated cage geramanoxanes and dimethylsilylated cage siloxanes afforded porous solids. Functionalization of the corners of germanoxanes with silyl groups should provide valuable building blocks in various functional materials.     

Total Synthesis of Terpioside B

The first total synthesis of terpioside B ( 1 ) has been accomplished. Key steps include the stereoselective installments of a set of challenging 1,2-cis-glycosidic linkages. Thus, α(1,4)-linked d -galactoside was effectively constructed from a 1,2-anhydrogalactose donor and an unprotected 1,6-anhydrogalactose acceptor by using a boron-mediated aglycon delivery (BMAD) method. In addition, α-l -fucofuranosides were stereoselectively and simultaneously constructed by remote group-assisted 1,2-cis-α-stereoselective glycosylations.     

Cyclic and linear amidine catalysts for the efficient synthesis of cyclic trithiocarbonates from carbon disulfide and episulfides under mild conditions

Cyclic and linear amidines effectively catalyzed the reaction of carbon disulfide and episulfides under mild conditions, such as ordinary pressure and ambient temperature, to give the corresponding cyclic trithiocarbonates in high yields.