Conformation of dimer (dihydroxydiphenyl methane) was investigated by the CNDO/2 method. The stable conformation of the above compound is a roof-type model with respect to the two benzene rings connected by the methylene group, and the most stable structure is a roof-type model with an intermolecular hydrogen bond between the two OH groups. The intra-molecular hydrogen bond energy was estimated to be 4. 2 kcal/mol by the CNDO/2 method.
On the other hand, the conformation of trimer was investigated by the same method. Trimer has fundamentally two conformations with respect to the three benzene rings. The first and third benzene rings connected to the second benzene ring are placed at the opposite side (trans-type) and at the same side (cis-type), respectively. The most stable model is trans-type and has two intra-molecular hydrogen bonds among the three OH groups. However, the cis-type model with two intra-molecular hydrogen bonds is the second stable one. The energy difference between the above two models is about 0.8 kcal/ mol. The electron charge density of the H atom of OH group participating in the intra-molecular hydrogen bond systems is decreased as the intra-molecular hydrogen bond becomes longer. This result suggests an increase of acidity of the higher molecular weight phenol novolac oligomer.

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N, N′-Bis (3, 5-diamino-triazinyl) diaminomethane (dimer) was synthesized to measure its ultraviolet absorption spectrum. From the reverse phase liquid chromatographic measurement, the synthesized product consists of mainly N, N′-bis (3, 5-diamino-triazinyl) diaminomethane, but the product contains partially monomethylol dimer and related compounds.
Measurement of ultraviolet absorption spectrum of the dimer which was separated from the synthesized products by the liquid chromatography was carried out in 0. 1N-hydrochloric aqueous solution containing about 10% acetnitrile. Its ultraviolet absorption spectrum has the two absorption bands at 212 and 240 nm. These absorption bands are assigned to the π-π* transition. The absorption spectrum of dimer is fundamentally similar to that of monomethylolmelamine in a hydrochloric aqueous solution.
On the other hand, the π-π* transition energies and their oscillator strengths of the models for the dimer in hydrochloric aqueous solution were calculated by the CNDO/CI method. The observed absorption spectrum is close to the calculated spectrum of the di-cation models in which the two protons are attached to the ring N atom of the each melamine ring. Similarity of the observed spectra of the dimer and monomethylolmelamine and calculated results suggest that an electronic interaction between the two melamine rings connected by the the CH₂ group of the dimer is small..

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Photosensitive polymers which originally developed in printing engineering have been recently employed in a wide fields of engineering such as photofabrication, microlithography of LSI production, coatings and printed circuit. As the application of photosensitive polymers is expanded, the requirement for the polymer characteristics is becoming strict and complicated. In order to satisfy these strict demands, a large number of photopolymers have been developed by contriving the polymer structure or by trying to incorporate new photochemical reactions into polymers. In the present review, typical photochemical reactions applied to photopolymers and the examples of molecular design are described

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The Principle of solid state high resolution NMR is briefly sketched. Recent application of this technique to high polymers is reviewed for following categories : conformation, configuration, electronic state, anisotropy, degree of crystallinity, and molecular motion. The principle of NMR-CT (or NMR imaging) is also sketched. The application of this technique to an analysis of the distribution of cracks in epoxy resins is introduced.

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First part I and II of F. S. Granger's series “Condensation of phenols with formaldehyde” are introduced. In part I o-cresoldialcohol and di-o-cresylmethanedialcohol are isolated for the first time andin part II the weight loss of o-and p-cresoldialcohols are estimated for the purpose of studying the hardening reaction. Next the article of F. Hanus (1940), who confirmed the constitutions of the dialcohols discovered by Granger, is mentioned. Hanus began also the study of the weight loss of phenolalcohols by analytical method, and claimed that only one mole H₂O being separated out from the cresoldialcohols, while Granger thought that two mole H₂O should be evoluted. Introducing the theory of W. Charlton and L. E. Perrins (1947) and reexamining the data of Hanus, the present author pointed out the future problem of the weight loss during the heat hardening reaction of phenoldialcohols.

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