Lists
Lists
Smith, David Carroll (1964) Organo-metallic chemistry related to boron, mercury and zinc. Doctoral thesis, Northern Polytechnic.
Boron and Mercury:
As an extension to work carried out at the Northern Polytechnic on the preparation of arylmercury halides, several halogen substituted arylmercury chlorides were prepared by decomposition of diazonium mercury trichloride complexes with copper bronze "in situ" at 0 °. The low yields obtained are ascribed to exchange of mercury for copper at the decomposition stage, with subsequent occurrence of a modified Sandmeyer reaction. Halogenated benzenes were produced in considerable quantity, and in some cases, trace amounts of symmetrical dihalogenated azobenzenes. Mechanisms are suggested for the decomposition of the diazonium complexes to give arylmercury chlorides, and for the modified Sandmeyer reaction.
The preparation of phenylboron dihalides, including phenylboron bromochloride, from phenylmercury halides and boron trihalides was investigated. A mechanism involving a cyclic four-centre transition state is suggested for the formation of phenylboron dihalides by this method.
Zinc:
In the hope of finding prototype reaction schemes which may produce compounds containing zinc-nitrogen covalent bonds, three systems were examined.
(a). The dichlorobis-(dialkylamino)-zinc(II) complexes ZnCl2.2R2NH(R = Et, Prn, Bun) on pyrolysis did not evolve hydrogen chloride but eliminated amine. During such heat treatment, redistribution of alkyl groups attached to nitrogen occurred, and the existence of polarised complexes are suggested to account for transalkylation without isomerisation.
(b). The thermal interaction of di-n-butylzinc and an aliphatic secondary amine R2NH gave the dialkylamino zinc butyl R2NZnBun, but further reaction was complicated by the precipitation of zinc and the formation of tetra-alkylhydrazine derivatives. The reaction products also contained amine derivatives by disproportionation and decomposition of dialkylamino radicals R2N.
(c). The reaction between dialkylaminomagnesium halides R2NMgX (prepared from the amine and alkylmagnesium halide) and zinc halides, failed to produce isolable dialkylaminozinc derivatives.
 |
View Item |