Masahiko Suenaga

Studies on the translational and rotational motions of ionic liquids composed of N-methyl-N-propyl-pyrrolidinium (P13) cation and bis(trifluoromethanesulfonyl)amide and bis(fluorosulfonyl)amide anions and their binary systems including lithium salts

Room-temperature ionic liquids (RTIL, IL) are stable liquids composed of anions and cations. N-methyl-N-propyl-pyrrolidinium (P(13), Py(13), PYR(13), or mppy) is an important cation and produces stable ILs with various anions. In this study two amide-type anions, bis(trifluoromethanesulfonyl)amide [N(SO(2)CF(3))(2), TFSA, TFSI, NTf(2), or Tf(2)N] and bis(fluorosulfonyl)amide [N(SO(2)F)(2), FSA, or FSI], were investigated. In addition to P(13)-TFSA and P(13)-FSA, lithium salt doped samples were prepared (P(13)-TFSA-Li and P(13)-FSA-Li). The individual ion diffusion coefficients (D) and spin-lattice relaxation times (T(1)) were measured by (1)H, (19)F, and (7)Li NMR. At the same time, the ionic conductivity (σ), viscosity (η), and density (ρ) were measured over a wide temperature range. The van der Waals volumes of P(13), TFSA, FSA, Li(TFSA)(2), and Li(FSA)(3) were estimated by molecular orbital calculations. The experimental values obtained in this study were analyzed by the classical Stokes-Einstein, Nernst-Einstein (NE), and Stokes-Einstein-Debye equations and Walden plots were also made for the neat and binary ILs to clarify physical and mobile properties of individual ions. From the temperature-dependent velocity correlation coefficients for neat P(13)-TFSA and P(13)-FSA, the NE parameter 1-ξ was evaluated. The ionicity (electrochemical molar conductivity divided by the NE conductivity from NMR) and the 1-ξ had exactly the same values. The rotational and translational motions of P(13) and jump of a lithium ion are also discussed.

Facio: New Computational Chemistry Environment for PC GAMESS

Windows環境におけるフリーの分子軌道計算プログラムであるPC GAMESSのための新しい計算化学統合環境の開発を行った。分子モデリングの機能については、市販のモデリングソフトに匹敵するものを実装した。モデルの描画にはOpenGLを用いているため精緻な３Ｄモデルの作成ができる。GAMESSの入力データの作成および計算の起動はGUIを介して支援され、計算結果の可視化については、最適化構造、分子軌道、静電ポテンシャル・電子密度の等値表面の表示、基準振動のアニメーション表示、赤外・ラマンスペクトルのシミュレーション等を実装している。更に、最適化構造は計算終了後直ちにモデルに反映されるので、GAMESSと連携したモデリングができる。このように、PC GAMESSを中心とした計算化学に必要な種々機能が統合されているため、作業が効率的となる。

A facile synthesis of [3ncyclophanes, in which aromatic rings are connected with -CH2CO-CH2- bridges☆

Abstract The title compounds, I, were synthesized by the dialkylation of TosMIC, II, with appropriate bis (halomethyl) compounds, III, under phase-transfer condition, followed by acid hydrolysis.

The Proton Cryptate of Hexaethylenetetramine

The next higher homologue of hexamethylenetetramine was synthesized as the proton cryptate H+ @1⋅Br- (shown schematically), and its X-ray structure determined. The proton trapped by the lone pairs accumulated at the center of the T-symmetric tetraaza cage could not be exchanged or removed, even after heating for three days in 3 M NaOD.

Synthesis, optical properties, and electronic structures of fully core-modified porphyrin dications and isophlorins.

The synthesis, structures, optical properties, and electronic structures of the tetraphenyltetrathiaporphyrin dication (S(4)TPP(2+), 6) and tetrakis(pentafluorophenyl)tetrathiaisophlorin (S(4)F(20)TPP, 7) are reported. S(4)TPP(2+) (6) and S(4)F(20)TPP (7) were synthesized by acid-catalyzed condensation of the corresponding hydroxylmethylthiophene, followed by oxidation. The electronic structures of S(4)TPP(2+) (6) and S(4)F(20)TPP (7) were analyzed by using UV/Vis-absorption spectroscopy and by magnetic circular dichroism (MCD) spectroscopy and the bands were assigned by using time-dependent density functional theory (TD-DFT) and ZINDO/s calculations. A red-shift of the Q bands of S(4)TPP(2+) (6) is observed relative to the spectra of tetraphenylporphyrins because a destabilization of the HOMO leads to a narrower HOMO-LUMO band-gap. Michls perimeter model was used to assign the absorption bands and MCD spectra of S(4)F(20)TPP (7). Current-density maps and nucleus-independent chemical-shift (NICS) calculations of S(4)TPP(2+) (6) and of a model compound predict marked modification to the diamagnetic ring current, whilst nonaromatic character is predicted for S(4)F(20)TPP (7).

Synthesis of (Aza)n[3n]cyclophanes as host molecules

(Aza)n[3n]cyclophanes were synthesized by the coupling reaction of p-toluenesulfonamide and bis(halomethyl) derivatives in the presence of a base (K2CO3, NaH etc.) using DMF, dioxane etc. as a solvent, in acceptable yields. Tetraaza macrocyclic compound (the dimer in Fig. 1) obtained by the coupling of 2,ll-diaza[3.3]metacyclophane with 1,3-bis(bromomethy1)benzene gave a l:l adduct with benzene.

DAS PROTON-CRYPTAT VON HEXAETHYLENTETRAMIN

Das nachsthohere Homologe des Hexamethylentetramins wurde als das Proton-Cryptat H+@1⋅Br− (schematisch gezeigt) hergestellt, und dessen Kristallstruktur wurde ermittelt. Das Proton, das durch die im Zentrum des T-symmetrischen Tetraazakafigs befindlichen freien Elektronenpaare festgehalten wird, konnte sogar durch dreitagiges Erhitzen in 3 M NaOD nicht ausgetauscht oder entfernt werden.

Synthesis of the Trinaphthophenalenium Cation

Two successive intramolecular condensations afford the trinaphthophenalenium cation 1, containing a C3h-symmetric new π system, as a dark violet solid. In this reaction a methoxy substituent in the precursor is used first for the activation of an aromatic carbon, second for the stabilization of the cationinc center formed during the first condensation, and finally as a leaving group.

Synthese des Trinaphthophenaleniumions

Zwei aufeinanderfolgende, intramolekulare Kondensationen fuhren zum C3h-symmetrischen, dunkelvioletten Titelkation 1, das ein ausgedehntes π-Elektronensystem enthalt. Bei der Synthese von 1 wird in einer Vorstufe eine Methoxygruppe eingefuhrt, die erstens fur die Folgereaktion aktivierend wirkt, zweitens die bei der ersten Kondensation entstehende positive Ladung stabilisiert und drittens als Abgangsgruppe dient.