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Two excited quintet states of 3,3′-dinitrenobenzophenone were observed by ESR in frozen organic matrix. One of their zero field splitting parameters were estimated to be D = 0.168 cm−1 and E = 0.024 cm−1.

High-resolution transmission electron microscopy (HRTEM) has been developed to possess functions of atomic force microscopy and scanning tunneling microscopy. Dynamics of subnano Newton-scale force and conductance were simultaneously observed at intervals of 1/30–1/3840 s during HRTEM imaging of contact, deformation and fracture processes between nanometer-sized tips. The experimental basis of the atomic-scale mechanics of materials was developed on the basis of the present microscopy.

Neutral fragments from the 248 nm laser ablation of polyarylsulfone (PAS) were investigated using laser post ionization (193 nm) time-of-flight (TOF) mass spectroscopy. Three regimes of ablation fluence were distinguished with respect to detected fragments and differences in their velocity distributions. Over the entire fluence range the arrival profiles of the products matched with a shifted Maxwell-Boltzmann distribution. Interestingly, average translational velocities revealed a non-monotonical dependency on ablation fluence. This is probably be due to screening effects of the ablation pulse by the plume, or to non-thermal effects that may contribute to the ablation process at high fluences. The dependencies of both the flight velocities and the Knudsen layer temperature of the fragments on fluence suggest that PAS ablation is photothermally driven. However, the excessively high values for average translational energies (up to 34 eV at high fluences) and their increases with increasing fragments amu indicate that the process also has some non-thermal features.

The surface of a fluoropolymer film was fabricated with micron-sized features by laser-induced backside wet etching (LIBWE), using a nanosecond XeCl excimer laser at 308 nm. The etch rate ranged from 5 to 20 nm/pulse by laser irradiation at fluences varying from 160 to 500 mJ/cm2. The threshold fluence for etching was about 100 mJ/cm2 in the case of a tetrahydrofuran (THF) solution containing pyrene. The mechanism of LIBWE is explained by the formation of superheated liquid in a cyclic multiphotonic absorption process.

Laser ablation of composite material consisting of elastomer and carbon black was performed using a KrF excimer laser. Remarkable sensitization of polymer ablation with carbon black was observed and cone-like microstructures were produced on the ablated surface. The development of large cones was due to the aggregation of carbon-rich cones by repeated etching and melting upon further laser irradiation. The cone-like microstructures revealed a visco-elastic property that could be useful in the applications of sealing and packing materials.

Irradiation of poly(tetrafluoroethylene) (PTFE) and poly(tetrafluoroethylene- co-hexafluoropropylene) (FEP) polymer films in an ammonia or hydrazine atmosphere with vacuum UV light resulted in a hydrophilic surface, where abstraction of fluorine atoms and introduction of nitrogen, oxygen, and hydrogen atoms occurred. We used Kr2 * and Xe2 * excimer lamps at wavelengths of 172 nm and 146 nm, respectively. The reaction mechanism for chemical surface modification is discussed on the basis of the results of X-ray photoelectron spectroscopy, secondary ion mass spectrometry, scanning electron spectroscopy, and attenuated total reflection Fourier transform infrared spectroscopy analyses.

Chemical vapor deposition of three kinds of 4-[ω(2-methylpropenoyloxy)alkyloxy]-4′-cyanobiphenyls (alkyloxy; ethyloxy, propyloxy and hexyloxy) was carried out using a polarized KrF excimer laser. The films deposited from the hexyloxy monomer, whose radical polymerization gave a side-chain-type liquid crystalline polymer, showed birefrengence and IR dichroism. The anisotropy of IR absorbance suggests that the direction of side chains of the polymer is parallel to the electric vector of the laser beam. The deposition of two other monomers, which yielded amorphous polymers because of the shortness of side chains, induced no molecular orientation. It was concluded that the molecular orientation took place due to an interaction between the liquid crystalline phase of the deposited polymer film and the polarized laser beam.

Perflucrooctyl-substituted cycloalkanes are prepared directly by photolysis of perfluoroazooctane in cycloalkanes upon 185 nm irradiation; a plausible mechanism is discussed on the basis of the time-course, quantum yield, and light intensity dependence during this photoreaction.

Poly(o-trimethylsllyl)-phenylacetylene (PTP) film, which was swollen in acetone under a high magnetic field of 15 T, showed birefringence and dichroism. Comparing the IR dichroism of magnetic-field-treated film with that of mechanically stretched film, it was found that the polymer long chain was aligned perpendicularly to the magnetic field. This alignment originated from the magnetic anisotropy of crystalline structures in PTP film.

Irradiation of 1,3-bis(diazo)indan-2-one (3) in an argon matrix at 10 K afforded the diazo ketene (7)via the photolabile diazo ketocarbene (5), and further irradiation caused the decomposition of the second diazo group to give strained carbonyl compounds as final photoproducts.

Azobenzenes in the host–guest Langmuir–Blodgett films prepared with amphiphilic β-cyclodextrin and azobenzene derivatives showed a photochromic behavior with complete reversibility owing to the free volume of cyclodextrin cavity, whereas the trans-to-cis isomerization was restricted in the case of the pure LB film prepared with long-chain azobenzene derivative alone. Thermal cis-to-trans isomerizations in the LB films were also studied.

The absorption spectrum of benz[cd]indazole is observed by low-temperature matrix photolysis of 1,8-diazidonaphthalene and is identified tentatively on the basis of its chemical behavior and the prediction of the spectroscopic data by SCF MO-CI calculations.

Langmuir–Blodgett films of host–guest complexes were fabricated for the first time using heptakis(6-dodecylamino-6-deoxy-)-β-cyclo-dextrin (1) and 4-(4-dimethylaminophenyl)azobenzoic acid. The guest molecule is included in the cavity of 1 with its long axis perpendicular to the film surface.

The photolysis of 2,3-diazidonaphthalene (3a) in a rigid matrix at 77 K gave the product having absorption bands in the 400–500 nm region, which has been assigned as α,ω-dicyano-o-xylylene (2a) by use of another precursor 1,2-dicyano-1,2-dihydrobenzocyclobutene. 2a has been also observed by the flash photolysis of 3a in fluid solution at room temperature, and the lifetime in methanol at 20 °C was 62 s. The dominating factor in the lability of 2a was the rigidity of the medium rather than the temperature. The reaction mechanism for the formation of 2a from 3a has been proposed as a monophotonic process involving the attack of the nitreno group on the azido group at the ortho position. Similarly, direct observations of α,ω-dimethoxy- and α,ω-diacetoxy-α,ω-dicyano-o-xylylenes have been given from 1,4-dimethoxy- and 1,4-diacetoxy-2,3-diazidonaphthalenes respectively.

The photocleavage reaction of naphthalene perp-fused cyclobutanes (I–IV) in rigid media is found to proceed from one (or several) of the upper triplet states. Nearly planar cyclobutanes (I–III), which were photocleaved in fluid solutions to yield acenaphthylene and 1,2-ethylenedicarboxylic acid derivatives, afford 1,8-naphthalenediacrylic acid derivatives in addition to the above products by irradiation in rigid media. Twisted cyclobutane (IV), which is considerably stable to irradiation in fluid solutions, was also photocleaved in rigid media to give dimethyl 1,8-naphthalenediacrylate. An NMR study shows that the formation of these diacrylic acid derivatives from I–IV in rigid media is considerably stereospecific. The yield ratio of diacrylic acid derivatives to acenaphthylene formed in the photolysis of I–III is independent of the viscosity of the solvents, i.e., of the matrix rigidity, but depends on other properties of the rigid solvents. A concerted mechanism is proposed for the photocleavage reactio...

The cis-isomer of p-Methyl Red (cis-p-MR) was appreciably stabilized by inclusion in equimolar amphiphilic heptakis(6-alkylamino-6-deoxy)cyclodextrins (CnN-CDs) in either chloroform solution or the Langmuir–Blodgett (LB) films, as compared with that in the isolated state. Amino moieties in the cyclodextrin derivatives were found to be essential for a tight inclusion of p-MR and also for the stabilization of cis-isomer.

The corona wind, with a velocity of several meters per second, is caused by applying high electric tension to bring about corona discharge in gases. In this paper the corona wind is experimentally and theoretically analyzed from an electrohydrod ynamical (EHD) standpoint. Experiments have been performed mainly in nitrogen by a two-dimensional electrode arrangement of a fine wire anode and a plate cathode. The voltage-current characteristics of an electrostatic probe indicate that positive ions predominate in the whole space except in an extremely narrow region close to the wire. A theoretical analysis has been conducted based on the model that positive ions produced by ionization near the wire electrode move toward the plate, introducing the bulk convective motion of neutral molecules as the result of collisions of ions and neutral molecules. The electric potential distribution in the space and pressure distribution on the plate calculated numerically agree well with the experimental data. Consequently, it is made clear that the corona wind is caused by the Coulomb force exerted on ions and collisions of ions and neutral molecules of gas.

Two derivatives of benz[cd]indazole were formed in rigid matrices by low-temperature photolyses of peri-diazidonaphthalenes: 5,6-diazidoacenaphthene containing more strain energy than 1,8-diazidonaphthalene and 1,8-diazido-3,6-dinitronaphthalene having strong electron-attractive groups. These indazoles were stable to prolonged irradiation in low-temperature matrices.

A Langmuir-Blodgett (LB) film of a novel amphiphilic β-cyclodextrin derivative containing a diacetylene group in the hydrophobic part was prepared, and its photochemical reaction was investigated. Intermolecular photopolymerization in the LB film was observed using UV-visible spectroscopy and gel permeation chromatography. The polymerized LB film was insoluble in organic solvents such as tetrahydrofuran and chloroform, and was immobilized on a glass plate.

立体保護を利用して安定に合成単離した薪規な環状ポリスルブイド〔4〕,〔5〕,〔6〕,〔8〕およびミポリセレニド〔9〕,〔10〕の光反応を検討した結果,容易に脱硫あるいは脱セレン化が進行し1,2-ジチオンおよびそのセレン類似体を生成すること,また種々のオレフィンを捕捉剤として共存させた場合に効率よくその環状付加反応生成物を与えることがわかった。また,1,2,3-セレナジアゾール〔1〕の熱反応によっても,4-t-ブチル-1,2,3-セヒオジアゾールをセレン源として用いることで,中間に1,2-ジセロンの生成が可能であることがわかった。さらに〔8〕,〔9〕,〔10〕およびその関連化合物の光分解に関し,低温マトリヅクス法を用いた電子スペクトル測定による反応追跡を行い,反応初期に生成する中聞体の構造に考察を加えた。特に1,2,5-チアジセレノール〔10〕の系においては,溶液中での光反応で見られた競争的脱硫および脱セレン化反応の共通め中間体と考えられるスピロチアセレニラン構造を有する薪規な反応活性種の存在を示唆する結果が得られた。

It was found that the unexpected phenazines were formed as minor products by the low-temperature photolysis of 2,2′-diazidobiphenyls in a rigid matrix. The phenazine formation results from the 1,1′-C–C bond fission of the biphenyl nucleus and suggests the aziridine intermediates. The low-temperature photolysis of 2-azido-2′-methylbiphenyl and 2-azido-2′,4′,6′-trimethylbiphenyl leads to the triplet-derived phenanthridine derivatives as major products.

The direct, triplet-sensitized, and low-temperature photolyses of 2,2′-diazidobiphenyl have been studied. The direct irradiation afforded 4-azidocarbazole, and the triplet sensitization resulted in the predominant formation of the azo dimer, accompanied by a low yield of benzo[c]cinnoline. The photolysis in a rigid matrix at 77 K afforded benzo[c]cinnoline quantitatively. The mechanism for its preferential formation in low-temperature matrix photolysis is discussed, and we propose a biphotonic process involving a dinitrene via a mononitrene.

In FY 1984, a national project called " The Development of a Super Heat Pump Energy Accumlation System" had been started by the MOON LIGHT PROJECT PROMOTION OFFICE of the Agency of Industrial Science and Technology. In this project, experimental study was carried out for a practical condenser by utilizing EHD phenomena. This report introduces results of the EHD effect on a vertical tube with three types of electrode at atmospheric pressure, and results of the EHD effect on a vertical tube bundle at high pressure. As a result, the condensation heat transfer coefficients of three types of electrode have been increased over about 3-4.2. Also, the condensation heat transfer of tube bundle has been achieved at the level of a single tube.

低温酸素マトリックス中での光化学反応により過酸化物中間体-シラノンオキシド〔7a〕およびペルスルキシド〔10a〕～〔12a〕を合成し,IRスペクトルにより検出した。酸素マトリックス中トリシランの光分解によりシリレンを発生させ,酸素分子との付加体を形成させた。18O2および16O18Oの同位体標識した酸素を用いることにより付加体が環状構造〔21b〕ではなく,開環形のシラノンオキシド構造〔2a〕を有することを明らかにした。理論計算1(HF/6-31G*)も行いジヒドロシリレン-酸素分子の三重項状態の付加体がシラノソオキシド構造を有し,振動解析の結果,O-O伸縮振動の吸収帯の理論値とジメシチルシリレン-酸素付加体の実測値が一致した。低温酸素マトリックス中スルフィドー酸素の接触電荷移動錯体のUV照射により付加体の生成をIRスペクトルにより確認し,同位体実験の結果,環状構造〔3b〕ではなく開環形のペルスルホキシド構造〔3a〕を有することを明らかにした。

Four kinds of amphiphilic aromatic compounds which one might expect to undergo efficient [2+2] or [4+4] photocycloadditions have been prepared for the investigation on photochemical reactions in Langmuir-Blodgett films. The properties of monolayers were very sensitive to molecular structure. The strong interaction of chromophores in LB films showed remarkable shift in electronic spectra.

An amphiphilic charge transfer complex with azobenzene introduced as a switching unit into the hydrophobic part was synthesized. The occurence of the reversible cis-trans photoisomerization of azobenzene in the Langmuir-Blodgett (LB) films depends on the state of aggregation of azobenzene. The conductivity in the LB film increases by ca. 20% on irradiation with UV light and reverts to the initial state on irradiation with visible light. The photoresponsive switching in the conductivity can be repeated more than 100 times without any noticeable fatigue.

The photochemical reactions of dimethyl 1,8-naphthalene diacrylate (I) in solution are found to be cis,trans isomerization and concomitant intramolecular cycloaddition through a triplet state (ET is ca. 40 kcal/mol). Cyclization reaction gives naphtho[1′,8′]bicyclo[3.1.1]hept-2-ene-6-exo,7-endo-dimethyl dicarboxylate (VI), its 6-endo, 7-endo substituted isomer (VII) and cis-anti-naphtho[1′,8′]bicyclo[3.2.0]hept-2-ene-6,7-dimethyl carboxylate (II) in a ratio of ca. 85: 10: 5. Predominant formation of crossed adducts is discussed, taking into consideration the ground-state conformations of (I). Biradical mechanism is proposed for the cyclization to explain the stereochemistry of the crossed products.

Monitoring of the photolysis of 1,2,5-thiadiselenole( 4 ) in low temperature matrix by electronic spectroscopy has implied an initial formation of a novel spirothiaselenirane intermediate, which is consistent with the competitive photochemical decarcogenation of 4 in solution.

XeCl excimer laser (308 nm) irradiation of RhH(CO)(PPh3)3 accelerates the homogeneous hydrogenation of olefins under mild conditions. Significantly enhanced dark reactions were observed after periods of laser irradiation. These demonstrate the generation of a highly active catalytic species. Furthermore, the apparent quantum yield of the reaction has been estimated to be larger than unity (2.4) under appropriate conditions. XeCl excimer laser-induced acceleration of homogeneous hydrogenation with other catalysts, RhCl(PPh3)3 as well as IrCl(CO)(PPh3)2 was also observed.

Transient absorbing in the 400–450 nm range was observed in the photolysis of 1,4-diacetoxy-2,3-diazidonaphthalene in rigid matrices at 77 K. The transient was assigned as α,α′-diacetoxv-α,α′-dicyano-o-xylylene by comparison with the low-temperature photolysis of the other precursors, 1,2-diacetoxy-1,2-dicyano-1,2-dihydrobenzocyclobutenes. The three o-xylylene stereoisomers showed differences in the longest-wavelength absorption maxima. Continued irradiation of the o-xylylenes converted them to 2-acetoxy-2-methyl[1,3]dioxolo[4,5-c]isoquinoline-5-carbonitrile as the result of the reaction of a cyano group with the o-xylylene system and the migration of an acetoxyl group. The rate of formation of the isoquinoline in rigid matrices depends on the viscosity of glassy solvents and the configuration of the intermediate o-xylylenes. The room-temperature photolysis of the diazide gave 2,3-diacetamido-1,4-naphthoquinone as the main product and compounds via the o-xylylene as minor products. A mechanism involving t...

The purpose of this study is to investigate unsteady characteristics of the annular impinging jet. Water and air were employed as working fluids. Two pressure transducers made of a semiconductor were installed, one being at the center of the disk placed downstream end of a inner tube and the other on an impinged flat plate. Cross-spectrum and cross-correlation functions of pressures were measured by varying a distance H between the annular nozzle and the impinged flat plate. It was found that there were four types of distinguishable frequencies for pressure, according to a value of H. It was ascertained that fluctuations with the large scale of the annular impinging jet had essentially two modes and the frequencies of these changed linearly with an issuing velocity alone of the annular jet. Some discussion of a cause of their generation took place.

It was described in the preceding paper that the recovery of actinoids were sometimes unsatisfactory. In this paper, some experiments on the recovery were carried out. Dependence of pH on adsorption (uptake) with glass fibre filter paper, influence of the presence of ammonium nitrate and calcium magnesium phosphate on the uptake were examined for uranium, neptunium, plutonium and americium. Centrifugation of the solution were also examined. In the case of solution containing calcium magnesium and phosphate, centrifugal experiments revealed that a very small amount of precipitate was formed at pH less than 5.0, and a close relation was found between precipitate formation and uptake or centrifuged out of the actinoids. As the results, it is thought that the actinoids are first coprecipitated with phosphate precipitate, then it is separated by the glass fibre filter paper. The amount of the precipitate may be influenced by the calcium magnesium contents in the sample, or by the conditions of the pH adjustment, and it has an effect on coprecipitation or counting efficiency of the actinoids. Consequently, it seems that some extents of the recovery fluctuation is unavoidable.

One remarkable phenomenon generated in an annular impinging jet is the formation of a reverse stagnation point at the center of the annular impinging jet on an obstacle or a flat plate. Because few of the heat transfer problems on the reverse stagnation flow have been reported so far, heat transfer at the reverse stagnation point has been experimentally studied by using the analogy between the heat transfer and the mass transfer of naphtha- lene. It was experimentally clarified that the flow pattern of the annular impinging jet was divided into three regions and that the Nusselt number at the reverse stagnation point had a weak dependency on the Reynolds number.

Mixed Langmuir–Blodgett (LB) films of (10-butyl-9-anthryl)-3-propanoic acid (1) and arachidic acid were prepared and their UV-Vis spectra were measured. Photodimerization of 1 in these LB films was successfully performed with monochromatic light.