Bulletin of the Chemical Society of Japan

Imai, Hideo; Yamashita, Kazuo

doi: 10.1246/bcsj.51.3103pmid: N/A

The solvation free energy of electrons in N,N-dimethylformamide, methanol, and water was estimated by means of electron photoemission into solution, and the data were compared with empirical parameters such as thermodynamic quantities, structural and kinetic parameters of solvents. It was confirmed that the interaction of an electron with solvent molecules is purely electrostatic and that the solvation free energy can be used as a tentative criterion of electrophilic properties of solvents.

Mochinaga, Junichi; Igarashi, Kazuo; Aoki, Toshio; Iwadate, Yasuhiko

doi: 10.1246/bcsj.51.3107pmid: N/A

Refractive indices of molten LaCl3, PrCl3, NdCl3, DyCl3, and YCl3 were measured by the cylindrical lens method. The measurements were carried out with the lights of four wavelengths, and the refractive indices so obtained were represented by empirical equations as linear functions of temperature. From the data molar refractivities were calculated. The refractive indices at infinite wavelength were calculated by use of Cauchy’s relation for dispersion, and electronic polarizabilities were obtained for the salt molecules in molten state, and also the electronic polarizabilities of La3+, Pr3+, Dy3+, and Y3+ ions in the melts were obtained.

Yanagida, Shozo; Takahashi, Kazutomo; Okahara, Mitsuo

doi: 10.1246/bcsj.51.3111pmid: N/A

The interaction of homogeneous polyethylene glycol(PEG) (EOn, n=1–8) with the alkali and magnesium metal cations and the ammonium cation was investigated on the basis of 1H NMR(PMR) downfield shifts in acetone-d6 or in acetonitrile-d3 The specific complexations of EO4 with Mg2+, EO6 with Na+ and Ca2+, and EO7 with K+ were demonstrated by PMR studies, and their solid complexes were isolated. No specific interaction was detected for Rb+ and Cs+ in PMR studies. The magnesium ion interacts strongly with 15-crown-5, 18-crown-6, and PEG in acetone, and the Mg(SCN)2-EO4 and the Mg(SCN)2-above crown ether complexes were isolated. The terminal hydroxyl groups of PEG play an important role in the complexation with Li+ and Mg2+ in acetone. The formation of the 1 : 1 complex with Ca(SCN)2 was observed both for EO6 and for EO7. Strontium and barium thiocyanates formed solid complexes with PEG(EOn, n=2–8) and with glymes(tri- to octaglyme). Some novel complexes of 12-crown-4 and 15-crown-5 with NaSCN and Ca(SCN)2 were also isolated . The mechanism of metal-ion complexation of poly(oxyethylene) derivatives is discussed in terms of the coordination geometry.

Onda, Masao; Yamaguchi, Ichiro

doi: 10.1246/bcsj.51.3121pmid: N/A

The microwave spectrum of o-chlorophenol-d has been observed in the frequency range 17–34 GHz. The rotational and centrifugal distortion constants have been obtained. The analysis of the hyperfine structure has given the following nuclear quadrupole coupling constants for the 35Cl species: χaa=−67.1, χbb=33.1, and χcc=34.0 (MHz). The spectrum assigned has been attributed to the s-cis-form (the hydroxyl hydrogen pointed toward the chlorine) from the consideration of the rs-coordinates of hydrogen and chlorine atoms. The non-bonded Cl…H distance is 2.373±0.001 Å.

Yamasaki, Nakamichi

doi: 10.1246/bcsj.51.3125pmid: N/A

The chemisorption of sulfur on thermally decomposed copper and iron sulfides was studied and its application to the desulfurization process of heavy oil was attemped. Thermal decomposition of sulfides was carried out by calcining CuS and FeS2 at 200–800 °C under 10−3 mmHg and with 5 °C/min. Sulfur was adsorbed on the calcined sulfides in toluene. Thermally decomposed copper sulfide (Cu/S: 1–2) easily chemisorbs free sulfur in toluene below 100 °C, but not iron sulfide (Fe/S: 1–0.5). The relationship between sulfur affinity and the structure of partially decomposed sulfide was discussed in terms of the kinetics of initial chemisorption of sulfur and the sulfur adsorption coefficient calculated from the ratio of the adsorbed sulfur to the sulfur required to reform starting CuS and FeS2. The partially decomposed copper sulfide (Cu1-2S) easily chemisorbs free sulfur in heavy oil. Chemisorption might be applied to the desulfurization of heavy oil.

Sunamoto, Junzo; Hamada, Tomiko

doi: 10.1246/bcsj.51.3130pmid: N/A

Configurational change takes place between tetrahedral and octahedral species, when cobalt(II) complexes are cosolubilized in reversed micelles formed by the cationic or ampholytic detergents in chloroform. This is accompanied by the elimination-addition reaction of ligand water from and to the metal ion in the reversed micellar core. The phenomenon is interpreted in terms of solvochromism and thermochromism. The nature and state of “naked” metal ion and “free” water molecule afforded in a highly restricted field of reversed micelles have been discussed on the basis of equilibrium constants and thermodynamic parameters for the configurational change, particular attention being given to the structure of micelles. Their resemblance to the active site of metalloenzymes is also discussed.

Yoshikawa, Satoshi; Ueno, Minoru; Meguro, Kenjiro

doi: 10.1246/bcsj.51.3136pmid: N/A

The monolayer properties of mixtures of poly(octadecyl methacrylate) and poly(butyl methacrylate) have been compared with those of their corresponding copolymers of octadecyl methacrylate and butyl methacrylate, using the measurements of their surface pressure-area isotherms at the air/water interface at 20 °C. The results showed that the isotherms of the mixed monolayers had three break points, and the surface pressures of the lower two break points agreed with those of poly(butyl methacrylate). This suggests that at lower surface pressures, the mixtures of the two homopolymers are compatible in a bidimensional state when each phase contains a small amount of the other homopolymer, and otherwise these are incompatible, while at higher surface pressures, up to 70 segment mol% of poly(octadecyl methacrylate) they are incompatible and above 80%, they are compatible. The copolymers showed characteristic isotherms different from those of the mixtures. The properties of the copolymers in the bidimensional state are affected by variations in the vitrified, liquid, or crystalline states with an increase in the mean lengths of the side chains in the three-dimensional state.

Lee, Ha Chung; Miyahara, Yutaka

doi: 10.1246/bcsj.51.3140pmid: N/A

Vapor-pressure depressions and electric conductivities at 40.3 °C have been measured for LiCl, LiBr, NaI, KI, and RbI in acetone. The greatest care has been taken to minimize the contact of salts and their solutions with air. In order to account for the data of vapor-pressure osmometry (VPO) for lithium salts in acetone, the dissociation-association equilibria of the salts, MX, expressed asM++X−\ightleftharpoonsMX\ightleftharpoons1⁄2(MX)2are proposed. The analysis of the conductance data of LiCl and LiBr, without considering the dimerization of the salts, leads to irrationally large values of the ionic association constants. For LiCl, NaI, and KI, VPO and conductometry give similar values of the dissociation constants, while for LiBr and RbI the agreement is not so satisfactory, though still within a factor of ten.

Egashira, Makoto; Kawasumi, Shohachi; Kagawa, Shuichi; Seiyama, Tetsuro

doi: 10.1246/bcsj.51.3144pmid: N/A

The adsorbed state of water on TiO2 was studied by temperature programmed desorption (TPD) in the range 0–1000 °C. Pure anatase and rutile samples, the TPD spectra of water from which were not affected by any contaminant, could be obtained by the hydrolysis of titanium oxalate and tetrachloride solutions, respectively. Two desorption peaks were observed for anatase with the peak maxima at 69–127 (I) and 191–256 °C (II), and three for rutile at 32–90 (I), 188–265 (II), and 310–356 °C (III). The sum of adsorbed amounts for peaks II, and III are within a monolayer coverage, that of peak I exceeding it. The enthalpies of adsorption were evaluated to be 36 and 55–69kJ·mol−1 for peaks I and II of anatase, and 36, 64, and 104 kj·mol−1 for peaks I, II, and III of rutile, respectively. From these results, the corresponding adsorbed species of peak I was tentatively assigned to physical adsorption, that of peak II to chemisorption on surface oxygen ion by hydrogen bond, and that of peak III to chemisortpion on Ti4+ by the coordination of oxygen atom of water molecule. The last species may be dissociated into surface OH groups.

Fukuda, Yasuo; Hattori, Hideshi; Tanabe, Kozo

doi: 10.1246/bcsj.51.3150pmid: N/A

The decomposition of 4-hydroxy-4-methyl-2-pentanone and the isomerization of 1-butene were carried out over La2O3, Y2O3, and CeO2. The activities for both types of reactions were in the following order; La2O3>Y2O3>CeO2. With La2O3, the change in the activity for the decomposition with the pretreatment temperature of the catalyst correlated well with the change in basicity, the activity and basicity maxima being observed when the catalyst was pretreated at 500 °C. Yttrium sesquioxide showed a maximum activity for the decomposition when pretreated at 700 °C. For the isomerizations of 1-butene and cis-2-butene, La2O3 exhibited activity maxima when pretreated at 700 °C. The cis/trans selectivities from 1-butene were considerably greater than unity, and the trans/1 selectivities from 2-butene were less than unity. The coisomerization of cis-2-butene-d0/d8 revealed that the reaction involved an intramolecular H(or D) transfer. The isotope effects for the formation of 1-butene from cis-2-butene were 4–10, while those for the formation of trans-2-butene were about 1.