Femtosecond Raman spectroscopy has been developed to investigate ultrafast photoinduced structural changes of materials. Vibrational modes in the photogenerated transient species are measured by stimulated Raman scattering using a Raman pump pulse with narrow bandwidth and a femtosecond supercontinuum probe pulse. The Raman signal can be measured without slowing the temporal response and broade...

We report an organic solid-state distributed feedback laser consisting of an organic active layer and a Bragg grating without morphological change. The active layer consists of 4-~dicyanomethylene!-2-methyl-6-~4-dimethylaminostryl!-4H-pyran as a laser dye, tris~8hydroxyquinoline! aluminum as a host, and poly~methyl methacrylate! as a binder. The threshold and linewidth of the laser are 400 mJ/c...

The title compound, C(19)H(18)O(7) [systematic name 5-hy-droxy-3,6,7-tri-meth--oxy-2-(4-meth-oxy-phen-yl)-4H-1-benzopyran-4-one], is a flavonoid which was isolated from the traditional Chinese medicine Laggera alata. The benzene ring of the benzopyran-one unit forms dihedral angles of 1.72 (3) and 37.39 (5)° with the pyran ring and the substituent benzene ring, respectively. The mol-ecular conf...

Isoflavone, Biochanin A, Dihydrobiochanin A, Phenylacetic acids, Fusarium javanicum After a lag-phase of 1 h a mycelial suspension of Fusarium javanicum completely degraded 5,7-dihydroxy-4'-methoxyisoflavone (biochanin A) to a series of transiently accumulating catabolites. The compounds were elucidated by spectroscopic techniques and are arranged in the first known degradative pathway for an i...

In this paper, 4-(dicyanomethylene)-2-t-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) has been used in interface modification of dye-sensitized solar cells (DSCs) with combined effects of retarding charge recombination and Förster resonant energy transfer (FRET). DCJTB interface modification significantly improved photovoltaic performance of DSCs. I-V curves shows the conversion...

This paper reports on the synthesis and characterization of two Schiff bases bearing 1,2,4-triazolic moieties, namely 4H-4-(2-hydroxy-benzylidene-amino)-5-benzyl-3-mercapto-1,2,4-triazole and 4H-4-(4-nitro-benzylidene-amino)-5-benzyl-3-mercapto-1,2,4-triazole using thin layer chromatography, melting interval, elemental analysis, spectroscopy and thermal stability studies.

2-Amino-3-cyano-4H-chromenes show great potential as novel anticancer agents. Here we report a quinine-catalyzed highly enantioselective formal 4 + 2 cycloaddition of ortho-quinone methides and malononitrile, providing a unique approach to 4-arylvinyl, 4-aryl and 4-vinyl 2-amino-3-cyano-4H-chromenes with excellent yields and enantioselectivities. Moreover, this reaction can be performed in up t...

An enantioselective (52-98% ee) Michael addition between cyclic β-diones and α,β-unsaturated enones was established in the presence of quinine-based primary amine or squaramide. A variety of cinnamones were smoothly converted into the desired 3,4-dihydropyrans in moderate to high yields (63-99%). Chalcones were also suitable acceptors and gave rise to the expected adducts in satisfactory yields...