NNN′N′-tetra-alkylethylenediamine complexes of some alkyl- and aryl-beryllium hydrides: the reaction of beryllium hydride–trimethylamine with pent-1-ene
The complexes (RBeH)2tmed (R = Et, Bus, But, n-C5H11; tmed =NNN′N′-tetramethylethylenediamine) are monomeric in benzene, as is the tetraethylethylenediamine (teed) complex of methylberyllium hydride, (MeBeH)2teed. Modified preparations of (PhBeH)2tmed,(PhBeH)2teed, and (BeH2)2tmed are described. The tmed complexes of beryllium hydride and of methyl- and phenyl-beryllium hydride, which previously have been regarded as polymeric since they do not dissolve in non-polar solvents, are soluble in chlorobenzene or in dichloromethane. Thus all the RBeH complexes with chelate diamines are now believed to have a fused seven-membered ring structure, at least in solution. The rates of the reactions of (BeH2,NMe3)2 and (BuiBeH,NMe3)2 with pent-1-ene are similar, and the former reaction gives the n-pentylberyllium hydride–trimethylamine complex rather than a mixture of (n-C-H11)2Be,NMe3 and unchanged (BeH2,NMe3)2.