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Poly-α-deuteroacrylonitrile and poly-α,β,β-trideuteroacrylonitrile were synthesized. α-Deuteroacrylonitrile was prepared by the deuterium exchange reaction of acrylonitrile with D2O in the presence of CaO. α,β,β-Trideuteroacrylonitrile was prepared by the addition reaction of C2D2 and DCN. The infrared spectra of polyacrylonitrile, the deuterated polyacrylonitriles, and the intermediate products of the syntheses were measured in the 4000–400 cm.-1 region and discussed. The polarized spectra of the oriented polymer samples were also measured. The bands of PAN in the CH stretching region exhibit reasonable shifts in the spectra of the deuterated polymers, while the C≡N stretching band shows no appreciable shift. The bands in the region lower than 1400 cm.-1 exhibit complicated behavior in deuteration. The calculation of the normal vibrations of polyacrylonitrile has been made, assuming a syndiotactic planar zigzag chain as a most simple model for calculation. The assignments of the bands are discussed.

High-resolution nuclear magnetic resonance (NMR) spectra of several kinds of polyesters were measured. Proton signals due to heterolinkages could be observed in some copolyesters, and the average sequence length and the degree of randomness in the copolyester were calculated from the intensities of their signals. A process in the transesterification reaction between two kinds of homopolyester was pursued with the NMR spectra. Random copolyester is formed by the ordinary molten-state copolycondensation and also during the transesterification reaction between two kinds of homopolyester.

ポリアクリロニトリル〓, (PAN) とその3種の重水素化物, -〓-(PAN-αd1), -〓-(PAN-βd2) および-〓-(PAN-d3) を合成し, それらの赤外スペクトルを4000～200cm-1の波数領域について測定した。PANのC-H伸縮振動に基く3個の吸収帯およびCH2はさみ振動による吸収帯は重水素化により予想される波数に移動し帰属が可能である。しかし, その他の1400cm-1以下に見られる吸収帯は重水素化物のスペクトルとの比較のみでは帰属が困難である。PANおよび3種の重水素化PANについて, Urey-Bradley力場を用い, GF行列法による基準振動の計算を行なった。分子構造は計算のために最も簡単であり, かつ可能性のあるモデルとしてシンジオタクチック平面ジグザグ鎖を仮定した。計算の結果は実測値との間に比較的よい一致が見られ, 各吸収帯の帰属を推定することができた。

Polarized infrared spectra of polyacrylonitrile, poly‐α‐deuteroacrylonitrile, poly‐β,β‐dideuteroacrylonitrile and poly‐α,β,β‐trideuteroacylonitrile have been measured in the region from 4000 to 200 cm—1. β,β‐dideuteroacrylonitrile was prepared by the hydrogen re‐exchange reaction of α,β,β‐trideuteroacrylonitrile with H2O in the presence of CaO. The calculations of the normal vibrations of polyacrylonitrile and these three polydeuteroacrylonitriles have been made, assuming a syndiotactic planar zigzag chain as the most simple model for calculation. The calculation was made by the use of the GF‐matrix method with the Urey—Bradley force field. The results show fairly good agreement between the observed and calculated frequencies. The assignments of the bands are given and discussed.