Polymerization of acrylamide initiated with pinacol–ceric ion redox system

Polymerization of acrylamide initiated with a pinacol–ceric ion redox system was investigated. The polymer obtained was found to contain one cerium atom in a polymer molecule. It was considered that the cerium atom was introduced into the polymer molecule by the termination reaction as there is no cerium atom in the initiating radical in the present system. A similar termination reaction was attained by ferric ion but not by cerous ion. The metal ion was considered to terminate the polymerization to form a stable polymer. Some considerations on the structure of the reaction product relating to the polymerization mechanism were discussed.     

The Hellmann-Feynman theorem applied to long-range forces

The relations between the Hellmann-Feynman forces in laboratory fixed (L-) and relative (R-) coordinate systems are clarified. In the usualL-coordinate system, the force is interpreted as force on nucleus, while in theR-coordinate system, it means force on whole particles consisting of the electrons and nuclei of each interacting subsystem. From a perturbation theoretical viewpoint, the concept of the force on whole particles correctly corresponds to the perturbation energy and is superior to the force on the nucleus.     

Non-linear structures in the non-critical NSR string

We investigate the Ward identities of theW symmetry in the super-Liouville theory coupled to the super-conformal matter of central charge . The theory is classified into two chiralities. For the positive chirality, all gravitationally dressed scaling operators are generated from theq–1 gravitational primaries by one of the ring generators in the R-sector acting on them repeatedly. After fixing the normalizations of the dressed scaling operators, we find that the Ward identities are expressed in the form of theusual W _q algebra constraints as in the bosonic case:W _n ^(k+1) ,=0, (k=1,...,q–1;nZ1–k), where the equations for even and oddn come from the currents in the NS- and the R-sector respectively. The non-linear terms come from the anomalous contributions at the boundaries of moduli space. The negative chirality is defined by interchanging the roles ofp andq. Then we get theW _p algebra constraints.     

Radiation-induced heterogeneous polymerization of acrylamide in acetone and acetone–water mixtures

The effects of temperature, dose rate, and monomer concentration on the heterogeneous polymerization of acrylamide in acetone–water mixtures have been studied. Heterogeneous polymerization takes place in mixtures containing less than 60 vol-% water. The polymerization is steady in acetone and nonsteady in acetone an nonsteady in mixtures containing 10–50 vol-% water. The average rate of polymerization is highest in mixtures with about 20 vol-% water. Polymer molecular weight increases with the increasing water content in range 0–10 vol-% and does not change in the range of 30–70 vol-% water. For the polymerization in acetone and an acetone–water 60/40 mixture the activation energies are 2.3 and ?1.8 kcal/mole, the dose rate exponents of rate are 0.78 and 0.52, and the monomer concentration exponents of rate are 0.5 and 1.6, respectively. The polymer molecular weight increases with decreasing dose rate, decreasing temperature, and increasing monomer concentration. These results are discussed in connection with the mechanism of heterogeneous polymerization and the solvent effect.     

Oxidative cleavage reactions of catechol and phenol to monoester of cis,cis,-muconic acid with the oxidizing systems of O2/CuCl,KOH/CuCl2

Oxidative cleavage reactions of catechol with CuCI to give monoester of cis,cis-muconic acid in pyridine containing alcohol was investigated under various conditions. The same oxidation was carried out also with the systems of KO₂/CuCl₂ and KOH/CuCl₂ in pyridine containing alcohol in the absence of oxygen. Phenol was oxidized with the same oxidizing systems to give the same monoester of muconic acid.     

Comparative pharmacokinetics of 67Ga among the different routes of injection

The pharmacokinetic study of 67Ga-citrate (67Ga) following intravenous (i.v.), subcutaneous (s.c.) and intraperitoneal (i.p.) injection was performed in anesthetized rats using the repeated blood sampling method by cannulation technique into the external jugular vein. The disappearance of 67Ga from the blood following i.v. and s.c. injection was best fit a three-exponential equation. There was no significant difference between the areas under the curves following i.v. and s.c. injection of 67Ga. In the case of i.p. injection, the disappearance of 67Ga from the blood was described by a two-exponential equation. However, the maximum blood radioactivity was very low, and the disappearance rate of 67Ga from the blood was extremely slow compared to the other routes of injection. The conclusion from these results was that s.c. injection was as suitable as i.v. injection, but i.p. injection was not appropriate for the distribution study of 67Ga such as scintigraphy or autoradiography. However, i.p. route may be available for a special experiment which needs the long-time retention of 67Ga in the blood.     

Preparation and properties of poly(imide-oxoisoindolobenzothiadiazine dioxides)

New thermally stable poly(imide-oxoisoindolobenzothiadiazine dioxides) (PIOD) have been prepared by the three-step cyclopolycondensation reaction of diaminobenzenesulfonamides with aromatic tetracarboxylic dianhydrides. The polymerization proceeded through the formation of poly(amic acid-sulfonamides) (PAAS), followed by cyclodehydration to yield polyimide-sulfonamides (PIS), which were subsequently converted to PIOD at 300°C. PAAS having inherent viscosities in the range of 0.1–0.5 in N-methyl-2-pyrrolidone (NMP) were obtained in approximately quantitative yield. PIOD were insoluble in most organic solvents, whereas PAAS and PIS were soluble in NMP and dimethyl sulfoxide. Differential thermal analysis and thermogravimetric analysis indicated that PIOD began to decompose at 460°C in air. The cyclodehydration of the model compounds was also investigated.     

A novel rearrangement reaction in doubly charged ion mass spectra of acetophenone derivatives

A novel rearrangement reaction for a methyl group is found in doubly charged ion mass spectra of p-substituted acetophenone derivatives. The driving force for the reaction is discussed.     

Novel ring transformation reactions of xanthine derivatives

The novel ring transformation reactions were found in the reactions of 1,3,7,9-tetra-alkyl-8,9-dihydroxanthines and acetylenic compounds. The reaction of the dihydroxanthine with DMAD gave a propellane type compound and with methyl propiolate afforded the similar type compound and a pyrimido[4,5-b]diazepine derivative. The mechanism of these reactions was also discussed.     

Experimental determination of ionization potentials of tetraphenylporphine and metallotetraphenylporphines

Gas-phase ionization potentials of tetraphenylporphine and some metallotetraphenylporphines have been determined by the method of photocurrent measurements in nonpolar solvents reported previously [1]. The values obtained range from 5.9 to 6.3 eV, depending on the central metal ion, correlating well with the reported polarographic oxidation potentials. It has been concluded that photoelectron ejection from these complexes in isooctane occurs from the porphyrin π-system in all cases including Co(II) tetraphenylporphine, in which the electron is thought to be removed from the metal in polar solvents.