Search

For the purpose of improving the visible method of γ-rays detection, detailed conditions with various acids have been examined for the color development of a fluoran-based black color former in acetonitrile. It is suggested that the protons (H + ), which may be produced from acid generators by γ-ray radiation, can be properly detected by the color development of the black color former containing proper kinds and concentrations of bases. Reversible decolorization through the interaction between Mg 2+ and polyamines (acyclic and macrocyclic) has been examined in order to reconfirm that the colored zwitterion is produced by the direct chemical interaction with Mg (ClO 4 ) 2 in the fluoran dye–acetonitrile solution.

チオフェン系アゾ色素は対応する置換アゾベンゼンより長波長側に吸収を示す。この現象（深色性）を明らかにする目的でベンゼン、チオフェン、フラン、ピロール、シクロペンタジエンおよびこれらのアザ置換体からなるアゾ化合物について量子化学計算をおこなった。まず、AM1、PM3、DFT計算によりそれぞれの安定配座を推定した。ついでチオフェン系アゾ化合物について硫黄原子の3d-AOを含めた場合と含めない場合のCNDO/S計算を行い、最長波長吸収帯に対する3d-AOの寄与は無視し得ることが確認された。さらに、CNDO/S法およびTD-DFT法によりスペクトル計算をおこなった。その結果、チオフェン系アゾ化合物が特異的に深色性を示すのではなく五員環系アゾ色素に共通した特性であることが示唆された。

Relationships between the HOMO energy and σ(p) in ylides 1-14 have been studied. Linear relationships between the HOMO energies obtained by HF/3-21G[*] and 6-31G*, BLYP/6-31G*, and B3LYP/6-31G* methods and the substituent constant (σ(p)) were found, respectively. Hence, for the electron donation of the ylide, it is noted that the HOMO energy can be used as a new parameter for predicting the basicity of SN ylides. By comparing the results obtained by these calculations, the best method is found to be B3LYP/6-31G*. The results of bond lengths and torsion angles obtained by DFT calculations correspond with that of X-ray structure determinations.

We report here a novel method of visualization to record Born's probability densities in glass blocks by the use of a recently developed three-dimensional laser technique. Conventional visualization methods cannot simultaneously show all the characteristic features of an atomic orbital, whereas a real image in a glass block in the present study allows us to recognize both the shape of the orbital and its wave character, such as the existence of spherical, planar and/or conical nodes, at the same time. One can take this block in one's hands and observe it from an arbitrary direction, to gain clearly the whole image of probability density in it. To show a physical image of the behavior of an electron in an atom is profitable for the understanding of atomic orbitals. This method is the most appropriate to understand images of "the probability density".

Symmetry elements in various hydrogen atomic orbitals are summarized with respect to quantum numbers n, l and m. The results are useful to improve the efficiency of drawing the isosurfaces of these orbitals.

Four dimensional hydrogen atomic orbital was investigated by a projection method to three dimensional space. The actual outputs were drawn on a two dimensional plane. Transparent plastic block mixed with a certain photochromic compound is expected to support the above visualization.

3,7-Bis(N,N-diethylamino)-10-(phenylthio)carbonylphenoxazine (1a) and its analogs (1b–f) were synthesized and the color change after γ irradiation was investigated. The color change of acetonitrile solutions of 1a ([1a]0 = 1.0 × 10−3 M) after γ irradiation was identified by naked eyes at the dose of 20 Gy. Phenylthio-substituted compound 1a showed more significant absorbance increase than phenoxy-substituted compound, 3,7-bis(N,N-diethylamino)-10-phenoxycarbonylphenoxazine (2a). The C‒S cleavage in 1a by γ irradiation was revealed to occur more easily than the C‒O cleavage in 2a. The sensitivity of the color formers (1a–f) to γ rays was correlated with the stability of the thiyl radicals generated in the reaction.

Relationships between the HOMO energy, the ν(C=O) stretching band, basicity(pKa), and σ(p) in phosphorus ylides have been studied. A linear relationship between the HOMO energies obtained by the AM1, HF/3-21G, and HF/6-31G methods and pKa was found. The same linear relationship was found between the HOMO energies obtained by these methods and σ(p)(indicated p-position). Thus, the HOMO energy can be adopted instead of pKa and σ(p) for choosing the ylide as the donor in organic reactions. In addition, a linear relationship between the ν (C=O) stretching bands obtained by these methods and the parameters described above was found. Hence, as for the electron donation of the ylide, it is noted that the HOMO energy can be used instead of pKa as a new method for showing the basicity of ylides. Furthermore, the ν(C=O) stretching bands obtained by these methods can be estimated by the HOMO energy obtained by the same methods.

A unique binding property of the PET (photoinduced electron transfer) sensor 1 is described, in which a naphthalene moiety at the 1,3-positions is attached by isothiouronium units that serve as anion-binding units. Fluorescence emission (λmax=339 nm) was significantly switched on at an excitation wavelength of 279 nm upon recognition of anion in 6% (v/v) H2O/MeCN solution at 25 °C. Titration curves with HPO42− and AcO− differ greatly; that with HPO42− shows a stoichiometric 2:1 host-to-guest binding, whereas that with AcO− shows a biphasic 1:1 and 1:2 host-to-guest binding, reflecting principally the charged shapes of the oxoanions. This finding is attributable to the plural built-in isothiouronium units with a high anion-binding ability, and suggests a new way to develop fluorescent sensors for oxoanion recognition.

A film device to visualize UV irradiation was successfully fabricated by an agarose solid film containing Fluoran dye, acid generator N-tosyloxyphthalimide and 2-propanol medium, and the mechanism and kinetics of this system were investigated. The reactions involving: (1) acid generation from N-tosyloxyphthalimide by UV irradiation, (2) acid generation from N-tosyloxyphthalimide by chemical amplitude reaction, (3) coloring reaction of Fluoran dye by acid were analyzed by changing the Fluoran dye concentration. The concentration of the colored Fluoran dye was determined by the absorbance at 520 nm appearing by UV irradiation. The kinetic constants of the three reactions were estimated by solving the differential equations by the formation of the colored Fluoran dye with changing the parameters based on a least square method. The result was in accordance with the experimental results to give reaction rate constants of the processes.

A leuco crystal violet analog, tris(4-N, N-dimethylaminophenyl)methanethiol (1) was synthesized and utilized to the γ rays detection system. Acetonitrile solution of leuco dye 1 showed significant absorbance change after γ irradiation of 1 Gy, and the change was more significant than those of tris(4-N, N-dimethylaminophenyl)methanol (2) and leuco crystal violet (3).

A novel phenoxazine color former, 3, 7-bis(N, N-diethylamino)-10-(2, 2, 2-trichloroethoxycarbonyl)phenoxazine (1), was synthesized. Acetonitrile solution of colorless 1 was observed to give blue cation 2a by γ irradiation of 10 Gy. Little absorbance changes were observed when the blue shade solution was kept for 6 d after γ irradiation. Compound 1 showed excellent sensitivity to γ rays and the resulting cation 2a was stable enough to provide a candidate for a novel dosimetry system.

The cleavage of C–O bonds in two fluoran-based dyes by the addition of alkali metal (M+ = Li+, Na+) and alkaline earth metal (M2+ = Mg2+, Ba2+) perchlorates in acetonitrile solution was examined by means of UV-visible absorption and 1H and 13C NMR spectroscopy at room temperature. Although the 1H NMR signals of the xanthene part of Rhodamine B base (3′,6′-bis(diethylamino)fluoran) were shifted toward lower fields, those of the isobenzofuran (or the benzoate) part were not shifted much upon the addition of M+ and M2+. The appearance of 13C signals at 163.6 and 162.4 ppm (vs TMS) in the presence of Li+ and Ba2+, respectively, confirmed the formation of the zwitterions from Rhodamine B base. The assignments of the 1H and 13C signals were performed by the HMBC method. The colored zwitterion of a practical black color former, 2′-anilino-6′-dibutylamino-3′-methylspiro[3H-isobenzofuran-1, 9′-(9H)xanthene]-3-one, was produced by the addition of M+ and M2+. The 13C NMR signals at 162.2 and 159.8 ppm in the presenc...

A chromoionophore-derived calix[4]crown, 1 , possessing an effective signal-controllable function by metal ionic inputs has been newly synthesized, whose function is mainly of our interest, by transforming the process of receptor activation to one that may be detected by an optical signal (i.e. color change), the basic feature of antagonist-agonist competition may be reproduced readily and visually detected. The process would be particularly new within the field of optical read-out receptors. Further, from the standpoint of material sciences, the controllable signal function may not only be welcome for molecular information processing, but also contribute to the design of new sensory materials.

New N -pyridinothiourea derivatives have been prepared by the high-pressure-promoted condensation of isothiocyanates with aminopyridines under uncatalyzed conditions. Complexation of the prototype 3c with diphenyl hydrogen phosphate was investigated by 1 H NMR, and the results suggest that it may be useful as a building block for hydrogen-bonding receptors.

An analyzer called “Q-chanG4” was developed with Visual Basic for photoluminescence quenching in a solid. This software can analyze the quenching mechanism in a solid matrix using emission decay curves and Stern-Volmer plots. Photoluminescence quenching of Tris(2,2’-bipyridine)ruthenium(II) in a polyethylene glycol solid by methylviologen was analyzed with Q-chanG4. The quenching mechanism was determined as a combination of a dynamic quenching and a static quenching involving multi-step equilibria and dynamic quenching. The dynamic quenching rate constant in the polyethylene glycol was as large as that in an aqueous solution, suggesting that the diffusion coefficient of molecules in the polyethylene glycol is almost the same as that in an aqueous solution in spite of the solid state.

水素原子の原子軌道をマルチメディア技術（静止画および動画）を用いて種々の表示方法（等値曲面, 擬三次元, 等高線, 断面図）で可視化するとともに, 対応する力学的振動についても同様に可視化した. 可視化結果を, CD-R (Compact Disk Recordable) に格納した. ランダム呼び出し可能な媒体の機能を使用して, 可視化データを任意に組合せて表示して対比させることにより, 節（節面）などの波の特徴を認識し, 原子軌道の波動性の理解を深めるよう工夫した.

A virtual bipolar photogalvanic cell was developed using Visual Basic. On the basis of the simulation, it is indicated that the charge separation (kd) and the charge recombination (kr) rate constants can be estimated using the photocurrent response. The thickness of the charge separation region can be anticipated by photocurrent response at various layer thicknesses. The increase in diffusion coefficients raises the short-circuit photocurrent to enhance the performance of the photogalvanic cell. An actual device was fabricated using tris(bipyridine)ruthenium(II) complex ([Ru(bpy)3]) as a sensitizer and Prussian Blue as a mediator. This device worked as a photogalvanic cell: short-circuit photocurrent (JSC), 2.3μA/cm2; open-circuit photovoltage (VOC), 0.118V; fill-factor, 20.5 %. It was shown from the action spectrum that electrons are transferred from [Ru(bpy)3] to Prussian Blue. The charge separation and the recombination rate constants were estimated, using the virtual device, to be 5 102 mol-1cm3s-1 and 6 109 mol-1cm3s-1, respectively.

A program written in JAVA language was developed for the virtual electrochemical measurement of a modified electrode with a finite diffusion thickness, e.g., an electrode coated with polymer film in which functional molecules were dispersed. This program, called ES-2, can simulate cyclic voltammetry and potential-step chronoamperospectrometry by considering the rate of charge injection from the electrode to the functional molecule and the diffusion of charge. The results are shown by a voltammogram (I-V curve), and concentration distribution in the layer at a series of voltages at cyclic voltammogram mode, I-t curve, and time dependence of concentration distribution in the layer at potential step mode and a text of current values, the fraction of the oxidized molecules (RCT ) and parameters used for the simulation in both modes. A dynamic textbook of electrochemistry can be constructed by this program combined with HTML text.

A program, called PLEC-1, has been developed with Visual Basic to simulate and analyze the electrochemical measurement of a polymer-coated electrode with dispersed functional molecules. The program has two independent buffers for oxidant and reductant per one material and can concurrently treat seven materials and three chemical reactions of either first- or second-order. The user can not only experience virtual cyclic voltammetry and potential-step chronoamperometry but also analyze cyclic voltammograms by the Gauss-Newton method using the program. In PLEC-1, simultaneous partial differential equations are solved by the combination of Crank-Nicolson and iteration methods.

5, 8-Diphenyl-5, 8-dihydroanthra[1, 9-bc:4, 10-b′c′]diquinoline (ADQ, 3) and its endoperoxide (ADQepo, 4) were photochromic compounds with high heat stability. By heating above 100°C, colorless ADQepo (4) was slowly converted to green ADQ (3) in toluene. Reaction of ADQepo with some protic acid gave ADQ (3) at room temperature. The mechanism of this reaction was proposed based on the measurement of electronic spectrum.

Electrochemical measurements in a three electrode system under finite conditions, e.g., at an electrode coated with a polymer film incorporating functional molecules have been simulated using a program written in the JAVA language. The simulation with or without a catalytic reaction by the functional molecules has been performed using the program. The shape of a cyclic voltammogram under finite conditions is different from that under infinite conditions applied to ordinary solution electrochemistry. The fraction of the functional molecules that accepted charges (RCT) has been calculated by integrating a concentration distribution. The current under finite conditions in a potential-step measurement deviated from that under infinite conditions above RCT ≈ 0.5. The program was introduced to a document on the electrochemistry written in HTML. It can be used by many students in an electrochemistry class without heavy loads on the server computer.

QTVR (QuickTime Virtual Reality) と呼ばれるソフトウェアを利用して，水素原子の原子軌道 19 種について対話型動画表示を実現させた．この動画表示が，量子化学の教育にどのように役立つか調査した．対話型動画の利用は，軌道の形状と数式の関係，節の形状と数式の関係を理解する手助けとなることがわかった．

The first absorption maxima of linear para acenoquinones (LPAs) were calculated by the Pariser–Parr–Pople molecular orbital (PPP MO) method using a novel, two-centre electron repulsion integral new-γ. The spectrochemical softness parameter k in the new-γ was evaluated from the absolute hardness, η PPP and η HMO , which were obtained by the PPP MO and the HMO level approximations, respectively. The first absorption maxima calculated using the new-γ with k obtained from η PPP are greatly improved to reproduce the observed values better than using the conventional Nishimoto·Mataga-γ function.

The sensitivities to γ rays were investigated for photo acid generators: N-sulfonyloxy phthalimide 2, N-sulfonyloxy succinimide 3, N-sulfonyloxy 1, 8-naphthalimide 4, N-tosyloxy 5-norbomene-2, 3-dicarboximide 5, triphenylsulfonium trifluoromethane-sulfonate 6, diphenyliodonium chloride 7 and chloroform 8. The acid generation efficiency was monitored by the use of acid sensitive dye, fluoran dye 1a. The efficiency for γ irradiation decreased in the order 7>2>6>5>3>4. In the case of 8, decomposition of 1a was accompanied. 7 and 8 were of no practical use because volatile hydrogen chloride was generated. The others (2-6) generate methanesulfonic acid, p-toluenesulfonic acid or trifluoromethanesulfonic acid which are not so volatile acid as hydrogen chloride. N-sulfonyloxy imide compounds (2-5) have an advantage for practical use as dosimeter because these reagents dissolve in either polar or nonpolar solvent.

原子軌道関数は, r, θ, φを極座標とするとき, 原子核からの距離rのみに依存する動径部分Rn,l(r)と,角部分Yl,m(θ, φ)の積で表される．角度θ, φのみに依存する角部分は, 球面調和関数としてYl,m(θ, φ)= Θl,m(θ)Φm(φ).の式で表わすことができる．角部分には, 波動関数の対称性に関する情報が全て含まれるため, 重要である．われわれは, AVS (Application Visualization System)というソフトウェアの等値曲面表示技術を用いて，原子軌道の角部分の数式を可視化する新しい方法を研究した. 本方法では, Yl,m(θ, φ)・rはデカルト座標の[(x, y, z)系]に変換可能であることに注目し, Yl,m(θ, φ) /r(x, y, z)の値を, 40×40×40の格子点に対して求めて, その等値曲面を描くことで,角部分表示を実現する．本研究では, Y0,0(θ, φ), Y1,0(θ, φ), Y1,±1(θ, φ), Y2,0(θ, φ), Y2,±1(θ, φ), Y2,±2(θ, φ)について,３次元の角部分の数式を可視化し, これまでと同等の表示が得られることを確認した．また, 本方法は４次元を超える原子軌道の角部分の可視化にも適用でき, 拡張性が高いことを確認した．

The excitation energies of the α-, β-, and p-bands of benzo-annelated polyacenes were estimated by the Pariser–Parr–Pople (PPP) molecular orbital calculation method using a novel concept for evaluating the two-centre electron repulsion integral, new-γA, in which the spectrochemical atomic softness (SCAS) parameter krA was taken into account. The value of krA was determined using the concept of the spectroactive portion (SP) and allotted to each carbon atom. The calculated results using new-γA were excellent for the simultaneous calculations of the p-, α- and β-bands of benzo-annelated polyacenes and were better than those obtained from the conventional N·M-γ or the usual new-γ. The C–C bond lengths calculated using new-γA reproduced quantitatively the observed values.

Due to our interest in the functionalization of dibenzo-30-crown-10 moiety, a regioselectively dinitro-derived congener 1 was conveniently synthesized. The availability of the compound as a building block to develop new molecular systems allowed us to prepare a multi-site receptor 3 , desirable for cooperative complexation of cationic and anionic species in an induced fit fashion. Indeed, K + accommodated in the crowned cavity did not only tune the conformation to bind anions but also associated in the anion binding efficiently.

Xantheno[1′, 9′ : 4, 5, 6]benzo[1, 2, 3-kl]N-(1-dodecyl-2-pyridynium)-acridine iodide (2a) was synthesized from 1, 5-dichloroanthraquinone in six steps. The polarized UV-VIS spectra of the LB film of (2a) on CaF2 were compared with the transition moments of (2a) calculated by semi-empirical molecular orbital method to discuss the orientation of (2a) in the LB film. The plane of the skeleton structure of the polycondensed aromatic ring of (2a) on CaF2 in the LB film was rather oblique, not parallel to the CaF2 surface.

The application of Windows 95/98/NT for PPP MO (Pariser-Parr-Pople molecular orbital) calculation was developed by using the Inprise C++ builder. The novel two-center electron repulsion integral (new-γ), the concept of spectrochemical softness parameter krs for PPP calculation, was introduced in this application. The user can perform quickly the modeling of π-conjugated compounds on a PC monitor and select many suitable parameters (for example, ionization potentials, resonance integrals etc.) for the PPP calculation. The SCF calculation was momentarily performed and oscillator strength and LCAO coefficients of HOMO, LUMO or others were displayed. The calculations gave satisfactory results for the prediction of the electronic absorption spectra of polycyclic aromatic hydrocarbons(PAHs), symmetric cyanins and so on.

The first absorption bands of the tetramethyl polyenyl cations were calculated by the Pariser-Parr-Pople molecular orbital method. By considering the extraordinary hyperconjugation effect of methyl substituents and using the new-y, the calculated absorption wavelengths reproduce well the observed ones.

Reaction of fluoran dyes 1a-1f with hydrochloric acid was investigated. Hydrochloric acid was added to the fluoran solution ([1a-1f]=1.0x10-4mol dm-3) in organic solvents, and absorbance of formed colored species 2a-2f was measured by UV-Vis Spectrometer. The increment of the electron donation ability of substituent X at 3-position of 1 resulted in the increase of the formation of 2. When the chloroform solution of the most sensitive compound 1a was irradiated with γ rays, the solution turned red even at dose of 1 Gy. In order to investigate the effect of acid generators, 1b was irradiated with γ rays. Tosyl chloride 4 showed the possibility as an applicant for dosimetry in place of diphenyliodonium chloride 5.

For Pariser–Parr–Pople molecular orbital (PPP MO) calculations of the p -band of fluoranthene derivatives, the values of the spectrochemical softness (SCS) parameter k in a novel two centre electron repulsion integral new-γ were evaluated based on the spectroactive portion (SP) of a molecular framework. The SP was determined by the character of MO calculated by the HMO method with reference to the structural analysis by ab initio MO calculations with 6-31G* level. The calculated excitation energies of the p -band of fluoranthene derivatives using the new-γ including k values based on the SP reproduced accurately the observed ones.

QTVR (QuickTime Virtual Reality) と呼ばれるソフトウェアを利用して，水素原子の原子軌道の新しい動画表示を行なった．これは，前もって種々の縮尺に相当する原子軌道を描画しておいて連続表示する方法である．この手法によれば，原子軌道の外側から近づいて原子軌道の内側に入っていくかのような効果，すなわち，仮想現実感が得られ，複数の球状の等値曲面を持つ 2s 以上の s 軌道や，複数の球状の節を持つ 5d3z2-r2 軌道などの等値曲面表示に有効であった．

Synthesis of a new bis-porphyrinic system coupled with biphenyl-20-crown-6 as an allosteric spacer, 1, is described; the incorporated rotatable biphenyl unit is capable of regulating the porphyrin center-to-center distance by an encapsulated metal ion in the crown-strapped cavity, so that the system displayed a potentially heterotropic allostery at the binding stage with a certain stereogenic α,ω-diamine guest, 2.

The steric hindrance at the 2-position of the fluoran ring and its influence on the electronic absorption spectrum were studied by semiemprical MO calculations. All fluoran dyes in this study gave two or more conformers by using structure optimization. Spectral changes and band shapes with respect to the steric hindrance of the amino group at the 2-position are discussed on the basis of calculations performed for a variety of conformations. A good correlation between the wavelengths of separated peaks and those of calculated peaks was obtained.

The reactions of sulfilimines with TCNQ were undertaken to investigate the electronic structure of the sulfilimine. The reaction of ylide bond (S = N) of sulfilimine with the multiple bonds (C = C or C ≡ N of TCNQ does not occur, but new charge-transfer complexes were formed as products. The molar ratio of the sulfilimine and TCNQ in new charge-transfer complex I was 1:1.3. This ratio was determined by elemental analyses. The results of various thermal analyses indicated that these complexes do not have definite melting points. The reason for this result is that the sulfilimine is instabilized by the weakened ylide bond in the complex, because IR data showed that the electron transfer from ylide bond to TCNQ in the complex occurs and as a consequence, the bond strength of ylide bond is weakened. ESR measurements of various sulfilimine-TCNQ complexes were performed. It was also clarified from the measurements of conductivities that the behaviors of conductivity of new complexes are similar to thos...

This article is concerned with our recent achievement in developing synthetic chromogenic receptors for optical active amines and amino acid derivatives. Pre-organized (S)-1,1′-bi-2-naphthyl- and bis(indophenol)-derived calix[4]crown 1a shows naked-eye detectable chiral recognition between those enantiomers. The spectroscopic properties are reported, as well as an estimation of the enantioselectivity using an HPLC equipped with a chiral packing column.

New fluoran leuco dyes incorporating a p-(N,N-dibutylamino)phenylamino moiety at the 6-position of 2,3-dimethylxanthene (1) and of 2-chloro-3-methylxanthene (2) have been synthesized. The spectral characteristics of these compounds were quite different from those of conventional flouran dyes; remarkably broad absorption bands in the range ca. 500–850 nm (λmax: 608 nm for 1, 645 nm for 2) were observed in m-cresol as a result of yielding zwitterions of 1 and 2. Coloured anions of these compounds were also formed in a basic methanol solution. The molecular structures of the colourless lactones and the coloured zwitterions were identified by 13C NMR spectroscopy. The new fluorans reported herein are promising compounds as a basic skeleton of new functional leuco dyes because of their unique spectral characteristics and colour properties in both acidic and basic media.