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Solvolysis/dehydrohalogenation rates of 2-chloro-2-methyladamantane (CMA) in 15 hydrogen-bond acidic and/or basic solvents are studied. The rates of reaction in these solvents have been correlated with the solvation equation developed by Kamlet, Abraham, and Taft. The linear solvation energy relationship (LSER) derived from this study is given by the following equation: log k = -5.409 + 2.219 + 2.505alpha(1) - 1.823beta(1) where , alpha(1), and beta(1) are the solvation parameters that measure the solvent dipolarity/polarizability, hydrogen-bond acidity (electrophilicity), and hydrogen-bond basicity (nucleophilicity). A high correlation coefficient (r = 0.996, SD = 0.191) was achieved. The cavity term, which includes the Hildebrand parameter for solvent cohesive energy density, delta(H), was not found to be statistically significant for this reaction substrate. The resulting equation allows calculated rates of reaction in other solvents and provides insight into the reaction pathway. In a previously reported correlation for another tertiary chloride, tert-butyl chloride (TBC), the coefficients for alpha(1) and are significantly larger and the coefficient for is statistically significant. In addition, the coefficient for beta(1) in the TBC correlation is positive, rather than negative, indicating that the transition states for TBC and CMA are significantly different. These results demonstrate why the uses of simple solvolytic correlation methods may be invalid even for comparisons of similar type substrates, e.g., tertiary chlorides. Also, these results provide confidence in the use of multiple linear regression analysis for predicting solvolytic rates in additional solvents.

The solution polycondensation of 1,4‐bis(hydroxydimethylsilyl)benzene with six bis(dimethylaminosilanes) was carried out by the aminosilane deficient method to give a series of high polymers. The bis(dimethylaminosilanes) were bis(dimethylamino)dimethylsilane, bis(dimethylamino)methylphenylsilane, bis(dimethylamino)diphenylsilane, 1,4‐bis(dimethylaminodimethylsilyl)benzene, 1,3‐bis(dimethylamino)‐1,1,3,3‐tetramethyldisiloxane, and 1,5‐bis(dimethylamino‐1,1,3,3,5,5‐hexamethyltrisiloxane). The condensation of dihydroxymethylphenylsilane with bis‐(dimethylamino)methylphenylsilane to give polymethylphenylsiloxane was also performed. A detailed description of the monomer syntheses and polymerization reactions is provided, since this paper represents the first detailed and systematic description of this polycondensation as an alternative to disilanol or disilanol‐dichlorosilane condensation routes. The thermal properties (i.e., Tg, TGA, DSC) of poly(p‐phenylenetetramethylsiloxane) are compared to those of poly[1,4‐bis(oxydimethylsilyl)benzenel] (where a Si(Me)2O group has been inserted between the silylphenylene units) as well as others in this series, polydimethylsiloxane, and polymethylphenylsiloxane. Similarly, these properties are compared with those of related polymers which include in‐chain ferrocene units. Introduction of Si(Me)2O units into poly(tetramethyl‐p‐silylphenylenesiloxane) systematically decreases Tg and thermal stability. Replacing SiCH3 with SiC6H5 groups increases Tg and thermal stability. Replacing in‐chain C6H4 with ferrocene increases Tg and slightly decreases thermal stability. The values of K and A in the Mark‐Houwink equation were determined for several polymers.

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