Takachiyo Okuda

Infrared spectra of methanesulfonanilide and its C- and N-deuterated compounds

Abstract The i.r. spectra of methanesulfonanilide and its deuterated compounds in the crystalline state have been studied. The vibrational assignments have been made on the basis of the isotope effects. The characteristic isotope shifts of the NH bending, the CN stretching and the SN stretching band have been found.

Concerning methoxy substituent effect and topotactic assistance by methylene chain on photocyclization of n-methylene dicinnamates

Abstract Methoxy substituent effect and topotactic assistance by the methylene chain of n-methylene dicinnamates upon the photocyclization to the cyclobutane derivatives was explored and the relative efficiencies were rationalized in terms of the odd electron densities of S 1 state obtained by the CNDO/S-CI excited state calculation.

Vibrational spectra of methanesulfonyl chloride and methanesulfonyl chloride-d3

Abstract The i.r. and Raman spectra of methanesulfonyl chloride and methanesulfonyl chloride- d 3 have been recorded in the liquid state, and consistent assignments of the fundamental frequencies of the two isotopic compounds have been given. The normal coordinate calculation based on a modified Urey—Bradley force field has been carried out to give the satisfactory fit between the observed and calculated frequencies.

Nature of radical reactivity of organic plasma-exposed glass surface studied by the electron spin resonance spin-trapping technique

In order to investigate the nature of radical ractivity of a plasma-exposed glass surface, we have carried out a number of reactions for phenyl-N-t-butylnitrone (PBN) spin-adduct formation in various organic plasma-exposed glass ampoules. Certain plasma-exposed glass surfaces where an ultrathin film was deposited afforded the PBN spin adduct in such reactions. Spin-adduct formation continued to occur for a long period of time if an appropriate solvent was chosen as an activator, demonstrating that such a glass surface can undergo a constant slow release of radical species. A kinetic study indicated that the rate-determining step for the formation of the spin adduct is the stage when an active radical species is leached out of the ultrathin film. Thus the mechanism by which the ultrathin film immobilizes the active radical species and permits its slow release is ascribed to the presence of weakened σ-bonds in the film and their facile bond fission by physicomechanical action of the solvents used.

Physicochemical properties of a plasma-exposed glass surface in a closed system. Mechanistic inter-relation between plasma-state polymerization and plasma-initiated polymerization

Physicochemical properties of a plasma-exposed glass surface under plasma conditions similar to those in plasma-initiated polymerization (brief plasma generation in a closed system) were investigated by SEM, X.p.s., wettability and electric conductivity measurements in order to elucidate how long-lived organic radicals can be trapped on such a glass surface.It was found that an invisible ultrathin polymer film was deposited on such a glass surface in the case of organic plasma exposure even under the above plasma conditions, although the physicochemical properties of the polymer film vary with the compounds submitted to plasma generation, and is largely different from those formed in the plasma-state polymerization.It has been suggested that the film can serve as an efficient host matrix for a variety of organic radicals which can be released under appropriate conditions so as to initiate the polymerization of various vinyl monomers.

Photochemistry of novel azabicyclic compounds; concerning the site- and regio-selectivity of di-π-methane transformations of 5,6-benzo-2-azabarrelenes

Abstract Acetone sensitized irradiation of novel 5,6-benzo-2-azabarrelenols were performed to afford di-π-methane photoproducts whose structures and ratios depended on the structural features and substituents; the phenyl substituent at C-8 rendered the pronounced effect on the formation of novel “cross-bonding” product through the imino-ether bridge, and importance of the product forming step for the observed regioselectivity was pointed out.

Experimental and theoretical studies on physicochemical properties of novel six-membered cyclic α-monocarbonyl azo-compounds

The preparation and physicochemical properties of a novel six-membered α-monocarbonyl azo-compound are reported. Low-temperature oxidation of 4,4-diaryl-3,4-dihydrophthalazin-1(2H)-ones (2) with lead tetra-acetate (LTA) in the presence of triethylamine in, CH2Cl2 afforded 4,4-diarylphthalazin-1(4H)-ones (3). Molecular orbital (MO) calculations on the model compound (8) of (3) disclosed on comparison with the corresponding azo-compound (7) and the αα′-dicarbonyl azo-compound (9) that the FMO properties of (8) are markedly different from that of (9). Thus, (8) should be a poor dienophile unlike (9), and analyses of the bond population indicated that (8) would undergo ready nitrogen extrusion as well as (7) and indeed, (3) was stable only below –60 °C. The MO calculations also indicated inherent 1,2-migration of the 4-substituent to the N(3) atom. 1,2-Aryl migration of (3) in acidic CH2Cl2 solution results in the formation of 3,4-diaryl-1-oxidophthalazinium betaine derivatives (13).

Apparent anomalous behavior of polar substituents on the benzene ring in the regioselectivity of di-π-methane rearrangement of 5,6-benzo-2-azabicyclo[2.2.2]octadienones

Abstract Polar substituent effects on the aromatic ring emerge in the regioselectivity of the di-π-methane rearrangement of the title compounds when they possess the structural feature of including the bridgehead carbon in a saturated ring; the importance of the environment at the bridgehead carbon is pointed out.

Antarafacial role of an aromatic nucleus; a novel regiospecific [π4a + π2a] intramolecular cycloaddition of the ene-ketene with an aromatic ring

Abstract The thermally generated ene-ketene undergoes a facile and regiospecific intramolecular cycloaddition with N,N-dimethylaniline to result in the novel formation of the azulenone derivative via a norcaradiene intermediate.

Six-membered cyclic α-monocarbonyl azo-compounds; a novel rearrangement of 4,4-disubstituted 1(4H)-phthalazinone to 3,4-disubstituted-1-oxidophthalazinium betaine

Abstract The characterization (IR) and evaluation of the reactivity (MO calculation) on one series of six-memebered cyclic α-monocarbonyl azo-compound are presented. A competitive process involving a novel acid catalyzed rearrangement and the nitrogen extrusion is also described.