Carborane polymers. II. Cyclic and polymeric formals

Autor: Murray S. Cohen, Joseph Green, Anatole P. Kotloby, Nathan Mayes
Rok vydání: 1964
Předmět:
Zdroj: Journal of Polymer Science Part A: General Papers. 2:3135-3146
ISSN: 1542-6246
0449-2951
DOI: 10.1002/pol.1964.100020712
Popis: Cyclic and linear formals containing a unique polycycloborane named carborane were prepared. The treatment of carborane glycols with formaldehyde or dipropyl formal yielded cyclic formals, linear polyformals, a mixture of linear and cyclic formals or no formal product depending upon the reaction conditions and the particular carborane glycol used. It was demonstrated that two of the carborane diols have a great tendency to form cyclic formals in solution or bulk-type reactions. In the reaction with 1,2-bis-(hydroxymethyl)carborane, the tendency to cyclize is greater than might be expected for a seven-membered ring. This propensity to form cyclic structure has been attributed to the short carbon–carbon bond and the relatively acute external angle of the group attached to the carborane nucleus. The stability of these cyclics has been demonstrated by failure to open the formal cyclics to form linear polymer. Polymer was obtained with bis(2-hydroxyethyl-1-carboranylmethyl) ether, however, neither cyclic nor polymer products were obtained with bis(2-hydroxymethyl-1-carboranylmethyl) ether. The failure to obtain the desired products have been attributed to the steric requirements of the carborane group.
Databáze: OpenAIRE
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