Azomethine derivatives. Part XII. Alkylideneamino-beryllium chlorides and bis(alkylideneamino)-derivatives of beryllium
Abstract
The compounds [(p-tolyl)2C:NBeCl]2, [({p-tolyl)2C:N}2Be]3, [(p-tolyl)ButC:NBeCl]2, and [{(p-tolyl)ButC:N}2Be]2 have been prepared by reacting BeCl2 with one or two moles of R1R2C:NLi. BeCl2 with 2Ph2C:NLi apparently similarly gives [(Ph2C:N)2Be]n; with Ph2C:NSiMe3 it gives (Ph2C:NBeCl)2. Four-membered (BeN)2 rings are believed to feature in the structures of all these compounds. In their i.r. spectra the colourless alkylideneaminoberyllium chlorides have ν(CN) in the region 1608–1614 cm.–1; the yellow bis(alkylideneamino)-derivatives at ca. 1630 cm.–1. [ν(CN,bridging)] and at ca. 1735 cm.–1. This last absorption, assigned ν(CNBe), is taken as evidence of linear CNBe groupings whereby terminal alkylideneamino groups are attached to three co-ordinate beryllium atoms. 1H n.m.r. spectroscopic details for [{(p-tolyl)2C:N}2Be]3 and [{(p-tolyl)ButC:N}2Be]2 are given.