Hidenori Itsuki

Partial molar volumes at infinite dilution for CmH2m+2 as solute in CnH2n+2 as solvent for m, n=6 to 16 at 298.15 K

Partial molar volumes at infinite dilution VB∞ for an n-alkane from n-hexane to n-hexadecane as the solute B in another of the same set of n-alkanes as solvent A were measured at 298.15 K by the dilatometric method. An empirical equation is proposed: VB∞/(cm3·mol−1) = {16.531 − 27.81/n2)mm}+27.95+54.60/n, for the solute B = CmH2m+2 in solvent A = CnH2n+2. This equation reproduces the experimental values within ±0.3 cm3·mol−1. Empirical expressions for the molar volume of a pure n-alkane and for the excess partial molar volumes at infinite dilution are also derived.

Partial molar volumes at inifinite dilution for 1-Cm−1H2m−1X as solute in the n-alkane CnH2n+2 as solvent for X = Cl, Br, I, CN, and OH, and n = 6, 9, and 12 at 298.15 K

Partial molar volumes VB∞ at infinite dilution were measured for 1-Cm−1H2m−1X as the solute B in CnH2n + 2 as the solvent A at 298.15 K where X = Cl (m = 5 to 13), Br (m = 5 to 13), I (m = 3 to 7), CN (m = 3 to 6), and OH (m = 3 to 9), and n = 6, 9, and 12. The deviation of VB∞ for the polar 1-Cm−1H2m−1X solute from that for the n-alkane CmH2m+2 solute having the same segment number of m in the same CnH2n+2 solvent is found to be almost independent of m for each of the homologues, and dependent on X and n. An empirical expression for the deviation is derived as a functional form with respect to n, the electric dipole moment in vacuum of CH3X, the contribution of X to the molar van der Waals volume of solute, and the contribution of X to the molar refraction of solute.

Preparative Liquid Chromatography for Macrolide Antibiotics.

マクロライド系抗生物質の分取液体クロマトグラフィー (分取液クロ) に対する操作設計の手法を開発するため以下の検討を行った.エリスロマイシンおよびエチルコハク酸エリスロマイシンをモデル物質および不純物とし, シリカゲル-有機溶媒系におけるラングミュア型吸着等温式および速度式のパラメーターを1成分クロマトグラムのモーメント値より得た.移動相の種類, 組成により吸着等温式のパラメーター値は変化し, 分取液クロにおける分離の程度が異なることを示した.移動相側境膜物質移動係数および固定相内物質移動係数の実験結果を既往の相関式と比較した.マーカム・ベントン型吸着等温式および各パラメーター値を用いて得た2成分クロマトグラムの計算結果は実測結果と良好に一致した.結論として, 本研究の方法で得たパラメーター値を用いてクロマトグラムの計算をすることでマクロライド系抗生物質に対する分取液クロの操作設計が可能になるといえた.

Preparative HPLC of Macrolide Antibiotics

Adsorption isotherms and mass transfer coefficients were measured for one of macrolide antibiotics, erythromycin, with combinations of spherical silica gel and various organic solvents. Measured and simulated chromatorgams agreed well for various combinations and several operating conditions. The effects of equilibrium and rate parameters on the shape of chromatogram were discussed from results of simulation.

Empirical correlations of partial molar volumes at infinite dilution of organic solutes and transition states for SN1 and SN2 ethanolysis of alkyl halides

Activation volumes are measured to be –21 to –29 cm3 mol–1 for the ethanolysis of t-butyl chloride and bromide and methyl bromide in ethanol at 318.15 K. Partial molar volumes at infinite dilution are measured for 34 organic solutes. Partial molar volumes of the transition states can be treated in the same way as those of common solutes, in which the partial molar volume of each solute is compared with that of an alkane having the same van der Waals volume. The volume changes caused by the molecularity of reaction and the intermolecular interaction during the activation process are discussed.

Empirical correlations of partial molar volumes at infinite dilution of organic solutes and transition states for SN2 hydrolysis and ethanolysis of n-alkyl bromides

Pseudo-first-order rate constants under pressures ⩽98.1 MPa have been measured for the hydrolysis of ethyl, n-propyl, and n-butyl bromides in water at 298.15 K and for the ethanolysis of methyl, n-propyl, and n-butyl bromides in ethanol at 333.15 K. Activation volumes (cm3 mol–1) were ca. –11 for the hydrolysis and about –25 for the ethanolysis. Partial molar volumes at infinite dilution were measured for n-butyl bromide in water at 298.15 K and for 66 organic solutes in ethanol at 333.15 K. Partial molar volumes of the transition states are shown to be adaptable to volumetric behaviour for, common solutes, in which the partial molar volume of each solute is compared with that of the n-alkane having the same van der Waals volume.