Light-scattering and intrinsic-viscosity data are presented for fractions of poly(p-bromostyrene) in monochlorobenzene and dioxane at 30°C, and in benzene at temperatures ranging from 25 to 50°C. The theta temperature for this polymer in benzene is 26.3°C. With the data for the statistical-radius expansion factor αs and the interpenetration function Ψ appearing in the second virial coefficient, the agreement between theory and experiment is examined with respect to the same two criteria as those employed in the previous study on poly(p-methylstyrene). The Yamakawa–Tanaka theory of αs and also the modified Flory theory are again found to satisfy both criteria. The data also reproduce the relationship between the cubed viscosity-radius expansion factor α_η³ and the excluded-volume parameter z if z is estimated using the Yamakawa–Tanaka equation for αs. Specifically, the first-order perturbation theory of α_η³ recently developed by Yamakawa and Tanaka compares well with the data near the theta temperature. The recent critical comments by Isihara and Nagasawa are also replied to.

We have made an Extended Hückel Self Consistent Charge (EH-SCC) molecular orbital calculation for hydrogen cyanide, hydrogen isocyanide and cyanide ion. The main purpose of this calculation was to compare the EH-SCC and the more accurate SCF MO calculations for HCN in order to evaluate the method we used here for future use. Specifically, we have calculated and compared the following properties of HCN: total energy, binding energy, variation of ground state energy with geometric conformation, ionization potential and dipole moment. In addition, we have extended previous calculations of HCN by also considering its energy variation with bond angle for two excited state configurations and deducing some of the characteristics of its electronic spectra. Finally we have also made an MO calculation of the isocyanide isomer HNC and CN⁻ ion to compare with and add to the known characterization of the H, C, N, system.

A method for the synthesis of 2,3,3-trimethyl-2-hydroxy-5-pyrrolidone has been developed. 3,3-Dimethyl-2-methylene-5-pyrrolidone is initially formed during its thermolysis and then readily dimerizes. 2,3,3-Trimethyl-2-cyano-5-pyrrolidone was synthesized by the reaction of 2,3,3-trimethyl-2-hydroxy-5-pyrrolidone with potassium cyanide.

In some recent papers (H. A. Stöckler and H. Sano, Phys. Lett.25(A), 550, 1967, and Phys. Rev.165, 406, 1968) the phenomenon of integral asymmetry of Mössbauer quadrupole doublets caused by anisotropy of atomic thermal vibrations has been called the “Karyagin effect.”

It is confirmed from NMR data on the polymers and the initiator that there are two distinct propagation mechanisms of stereospecific polymerization in the methyl methacrylate–9-fluorenyllithium initiator system.Various kinds of tactic poly(methyl methacrylate) were prepared by the use of 9-fluorenyllithium under various compositions of the mixed solvents of toluene–THF and at different polymerization temperatures. Their microtacticities estimated from high resolution nuclear magnetic resonance (NMR) spectroscopy were analysed with the aid of the testing formulae for ultimate and penultimate unit effects in propagation step. From these analyses it was found that the microtacticities were remarkably dependent on the composition of solvents and on temperatures. The dependence on the composition of the solvents appearing in the plots of the testing formulae have been interpreted reasonably well by the introduction of two kinds of propagation mechanisms.NMR spectra of 9-fluorenyllithium and -sodium were also measured. Chemical shifts of protons in these salts varied with the composition of solvents and temperatures. This behavior has been interpreted in terms of two kinds of ion pairs, i.e., solvent-separated ion pairs and contact ion pairs. This difference in the states of the catalyst must influence on the microtacticities of the polymer obtained. It is concluded that the two distinct propagation mechanisms in the stereospecific polymerization must have originated from the two different kinds of catalyst.