FUNDAMENTAL BASIS FOR CYCLOPOLYMERIZATION .I. UNCONJUGATED CHROMOPHORIC INTERACTIONS RELATED TO CYCLOPOLYMERIZATION

A far ultraviolet study showed progressive bathochromic wavelength shifts within the following series of compounds: (i) allyltrimethylsilane, diallyldimethylsilane, triallylmethylsilane, tetraallylsilane; (ii) allyltripropylsilane, diallyldipropylsilane, triallylpropylsilane; (iii) 4,4-dimethyl-1-pentene, 4,4-dimethyl-1,6-heptadiene, 4-allyl-4-methyl-1,6-heptadiene. In the series tri-methylvinylsilane, dimethyldivinylsilane, methyltrivinylsilane, and tetravinylsilane, trimethylvinylsilane was shifted bathochromically from the rest of the vinylsilanes, which were grouped together. Allyldimethylvinylsilane showed two independent absorptions. A homoconjugative, interspatial interaction is postulated as the cause of the progressive bathochromic shifts observed. The structures depicting this interaction are found to coincide with the structures postulated for the transition state of intra-intermolecular cyclopolymerization. The activation energy ratios for the free radical polymerization of the allylmethylsilanes are also found proportional to the shift ratios from the ultraviolet study. 4P-Dimethyl- 1,6-heptadiene and 4-allyl-4-methyl- 1,6-heptadiene were cyclopolymerized using a Ziegler catalyst. The physical properties of the soluble polymers obtained are reported. © 1969, Taylor & Francis Group, LLC. All rights reserved