On automorphism groups of some PCS graphs

In this paper we review the characterization of point-color symmetric (PCS) graphs based on the color preserving automorphisms given in [3]. In particular, we consider PCS pictures, arriving at another characterization theorem. We summarize a few results and give some examples.     

Magnetic field effect on the photoconductivity of poly-n-vinylcarbazole

Magnetic fields were found to increase the photocurrent in poly-N-vinylcarbazole (PVCz) films by up to 5–6% at 1 kG. This positive magnetic field effect was sensitive to both applied voltage and temperature, and was enhanced with dimethyl-terephthalate (DMTP) doping by a factor of two. Magnetic fields were also found to increase the prompt exciplex fluorescence of PVCz films doped with DMTP by up to 2% at 500 G. The observations made clear that a carrier generation process via an exciplex state has an important role in photo-carrier generation even in undoped PVCz films.     

Regio- and chemoselective transfer hydrogenation of quinolines catalyzed by a CpIr complex

An efficient method for the transfer hydrogenation of quinolines catalyzed by a Cp^∗Ir complex was developed. A variety of 1,2,3,4-tetrahydroquinolines were obtained by regio- and chemoselective transfer hydrogenation of quinolines using 2-propanol as a hydrogen source.     

Flavonol glycosides in leaves of two Diospyros species

Fourteen flavonol glycosides including two new compounds were isolated from the leaves of two Diospyros plants (D. cathayensis and D. rhombifolia). The structures of isolated compounds were determined by spectroscopic analysis. The scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical of the isolated compounds was also investigated.     

Novel and stereocontrolled synthesis of (+/-)-tetrodotoxin from myo-inositol

[reactions: see text] The novel and stereocontrolled synthesis of (+/-)-tetrodotoxin from myo-inositol is described. The key steps involve the stepwise oxidation of hydroxyl groups to the carbonyl function, followed by the addition of specific nucleophiles, including the successive spiro alpha-chloroepoxide formation and its ring-opening with the azide anion, to give the desired branched chain structures (5-->6, 17-->18-->19-->20 and 23-->24-->25) with the desired regio- and stereoselectivities in high yields. The stepwise conversion of the alpha-azido aldehyde 25 to the delta-lactone 29, followed by reduction of the azide, introduction of a guanidine moiety, aldehyde formation, and deprotection, produced the (+/-)-tetrodotoxin.     

Intermediate of the homomolecular oxygen exchange reaction at liquid nitrogen temperature

An O₄ intermediate is postulated instead of O₄^? for the homomolecular oxygen exchange reaction on ZnO (only at liquid nitrogen temperatures) by the parallel observations of O₂^? using oxygen-17 and of gas phase oxygen using oxygen-18.     

Total synthesis of (+/-)-mycoepoxydiene,a novel fungal metabolite having an oxygen-bridged cyclooctadiene skeleton

[reaction: see text] The first total synthesis of (+/-)-mycoepoxydiene has been accomplished. A ring-closing olefin metathesis (RCM) approach was employed for the construction of the oxygen-bridged eight-membered bicyclic skeleton. The RCM product was converted to the target natural product featuring the oxidative rearrangement of a furfuryl alcohol introduced as the side chain and the stereoselective 1,2-reduction of a delta-keto-beta,gamma-unsaturated alpha-lactol intermediate.     

Zooxanthellamide A, a novel polyhydroxy metabolite from a marine dinoflagellate of Symbiodinium sp.

A novel polyhydroxy metabolite named Zooxanthellamide A, C₁₂₈H₂₂₂N₂O₅₄S₂, was isolated from a cultured marine dinoflagellate, Symbiodinium sp., and the chemical structure was determined by spectroscopic methods.     

Deposition of Diamond-Like Carbon Film and Mass Spectrometry Measurement in CH4/O2 RF Plasma

The deposition of diamond-like carbon (DLC) film and the measurements of ionic species by means of mass spectrometry were carried out in a CH ₄ /O ₂ RF (13.56 MHz) plasma. The film deposition rate greatly decreased with increasing O ₂ content up to 10% O ₂ . The oxygen ion density indicated the remarkable increase with the increase of O ₂ content up to 10%. The hydrocarbon ion density is increased considerably by the addition of 5% O ₂ , and then decreased monotonically for O ₂ contents more than 5%. Many oxygenated hydrocarbon ions were detected in the CH ₄ /O ₂ plasma. They were classified into three kinds of ions: C _n H _m O ⁺ , C _n H _m OH ⁺ , and C _n H _m O ₂ H ⁺. When the O ₂ content was increased, the higher hydrocarbon C _n H _m ⁺ (n2) ion densities (except C ₂ H ₄ ⁺ ) decreased more than the principal (CH ₃ ⁺ and CH ₄ ⁺ ) ion densities, since the generation of higher hydrocarbon ions would be suppressed by the formation of oxygenated hydrocarbons. It was also suggested that the great decrease in the film deposition rate in the CH ₄ /O ₂ plasma was mainly associated with considerable decrease in the higher hydrocarbon ion densities. The properties of DLC film obtained in CH ₄ /O ₂ plasma did not indicate considerable change from those obtained in pure CH ₄ plasma.