Neopentyl, neophyl, and trimethylsilylmethyl compounds of manganese. Manganese(II) dialkyls; manganese(II) dialkyl amine adducts; tetra-alkylmanganate(II) ions and lithium salts; manganese(IV) tetra-alkyls

Authors:
Publisher website
Google Scholar
Abstract
The interaction of manganese(U) chloride with Grignard or dialkylmagnesium reagents derived from Me3CCH2Cl. Me2PhCCH2Cl, and Me3SiCH2Cl yields thermally stable dialkyl compounds of manganese(II). For the neophyl compound. Mn2(CH2CMe2Ph)π. a dimeric structure with a bridging alkyl group, the phenyl group of which lies over a manganese atom, has been confirmed by X-ray diffraction (to be reported separately). For the trimethylsilyl-methyl compound, {Mn(CH2SiMe3)2}n, tetrahedral co-ordination of MnII is achieved by polymerisation via alkyl bridges (cf. BeMe2). The dialkyl compounds interact with Lewis bases such as NNN′N′-tetramethylethylenediamine to give mono-meric complexes of the type MnR2·tmed and with lithium alkyls to give solvated dilithium tetra-alkylmanganate(II) complexes Li2[MnR4]. Salts where R = Me are also described and the existence of dimethyl- and dlphenyl-manganese is questioned. The e.s.r. spectra of the manganese(II) species are described and assignments made. Oxidation of the dialkyl compounds in the presence of an excess of alkylating agent gives green solutions whose e.s.r. spectra are similar to that of tetranorbornylmanganese(IV) so that the solutions presumably contain unstable manganese(IV) alkyls.