Borazine, -BH-NH

Borazine, (-BH-NH-)3, is formed by heating solutions of H3N-BH3 in ether or acetonitrile, as shown by B NMR [1], and in the thermal dissociation of H3N-BH3, as shown by thermogravimetry (TG) and differential thermal analysis (DTA) [2]. The thermal decomposition mass spectra of (-BH2-NH2-)n under El conditions contain the ions [B3N3H5] as the base peak and [B3N3H6] with 39% relative intensity [3]. 

By application of valence shell electron energy loss spectroscopy, inner shell electron energy loss spectroscopy, magnetic circular dichroism spectroscopy, as well as photoelectron and electron transmission spectroscopy it can be deduced that the ji-electron system of borazine resembles that of benzene [8]. Table 4/13 presents the Rydberg term value matrix and Table 4/14 the energies and assignments from the electron energy loss spectrum (EELS) [8]. 

Rydberg Term Value Matrix for Borazine in eV (in parentheses cm ) [8]. 

Energies and Assignments of Features Observed in the Boron-1 s and Nitro-gen-ls Electron Energy Loss Spectrum of Borazine [8]. 

Estimated from alignment of the Bis, Nls ji peaks of borazine with those of benzene and assumption of equal term values for the transitions to Jt (e ) in all three spectra. 

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The cyclic borazine (-BH-NH-)3 and its derivatives form one of the largest classes of B-N compounds. The parent compound, also known as inorganic benzene , was first isolated as a colourless liquid from the mixture of products obtained by reacting B2H6 and NH3 (A. Stock and E. Pohland, 1926) ... 

Borazine, (BH)3(NH)3, is an analog of CgHg, benzene. It can be prepared from the reaction of diborane with ammonia, with hydrogen as another product or from lithium borohy-dride and ammonium chloride, with lithium chloride and hydrogen as the other products, (a) Write balanced chemical equations for the production of borazine using both synthetic methods, (b) Draw the Lewis dot structure of borazine. 

This boraphosphene compound is the phosphorus analogue of borazine (NH-BH)3 (9.60a) and, like the latter, is probably based on a delocalised p bonding system which can be at least partially represented as (9.60b) [24]. Equal ring distances and a planar ring have been found in (9.60c) [25]. 

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