Alkoxy and related derivatives of main group elements

Abstract

A series of derivatives of the brominated alcohol 3-bromo-2,2- bis(bromomethy 1)-1 -propanol were prepared with a view to eventual use of such derivatives as flame retardants. The derivatives took the form of alkoxide compounds of main group elements, except for a few compounds of non-main group elements, which were added for their known application in the flame retardant field. Many of these derivatives were liquids at room temperature, so were of limited use for flame retarding polymers etc., but were of interest due to the trends shown in their spectra. Of the solid derivatives, the fully substituted monomeric boron and silicon compounds were tested by high temperature DSC & TGA techniques. The silicon derivative showed potential for application in ABS-type polymers, and would be worthy of further study. The simple orthoborate did not perform as well. The other solid species produced were tested by DSC to 400 C and the results reviewed. Derivatives of the brominated diol 2,2-bis(bromomethyI)-l,3- propanediol were also prepared, with the same aim. Some reactions of tetrahydroborate with 1,2-dihydroxybenzene or sulphur were studied. The spirocyclic bisdiol borate anion was successfully prepared via this route, although the target of the monodioldihydro species was not formed. The reactions with sulphur were aimed at producing an active borane-type species, but were also of interest for the structural problems they raised. No definite conclusions were reached regarding the product of these reactions, however. Some work was also performed on a novel route to carboranes by reacting a carbene with a borane anion. The preliminary reactions did not indicate the presence of any carborane species.