Shizuo Fujiwara

Analysis of the Nuclear Magnetic Resonance Spectrum of a Six‐Spin System of Monofluorobenzene

This paper is concerned with the general analysis of a six‐spin system belonging to the point group C2V, using monofluorobenzene as an example. The apparatus used for the NMR measurements is the one constructed in this laboratory, operating at 27.030 Mc. The absorption lines calculated suggest the doublet structure of the spectrum, which is consistent with the observed spectrum. It was confirmed that this doublet structure is due to the spin‐spin couplings of the ring protons with fluorine. More precise comparison of the calculated results with the observed spectrum was made by integrating the intensities of the lines having a suitable line shape and width. It was noted that this procedure for constructing the absorption spectrum from the calculated lines is useful in the discussion of the power of resolution of the apparatus and the type of line shape.

Superfine Particle Magnetite

Superfine particle magnetites were prepared in crosslinked polyvinylalcohol (PVA) media. PVA gel prepared by Co⁶⁰ gamma irradiation was immersed in a mixed aqueous solution of ferric and ferrous chlorides and then in sodium hydroxide. Measurements of Fe₃O₄ concentration, residual magnetization, and coercive force were made. Data are presented in tabular form. (L.N.N.)

Chemical shifts of stilbene derivatives

Abstract The proton magnetic resonance chemical shifts of stilbene derivatives have been observed in carbon tetrachloride, cyclohexane, and benzene solutions. The observed shifts were compared with those calculated on the basis of Poples model of circulating π-electrons, assuming various kinds of molecular structures.

Determination of the State of Manganese in Japanese Limestones

本研究は前報につづき,天然の炭酸カルシウム中のマンガン(II)の存在状態を知る目的で行なわれ,岐阜県赤坂町地区石灰岩鉱床から採取した試料112種について,マンガン(II)イオンのEPRスペクトルとマンガン含量が測定された。その結果,マンガン(II)イオンの存在状態は全試料にわたり,全体としては孤立分散形であるが,スペクトルの超微細構造線の線幅の実測値は,マンガン(II)イオンが炭酸カルシウムの結晶格子中でまったく均一な分散分布をとって,カルシウム・イオンと同形置換していると仮定して得られる理論値よりもつねに大きく,したがって試料中のマンガン(II)イオンは不均一分散をとって存在していることが明らかとなった。なお,マンガン含量の最高値は590ppmで,100ppm以下の試料が全体の90%を占める。