Borazine borazines

An important observation supporting the need for resonance in the LE model is that there are only three different structures of dichlorobenzene (C6H4C12). How does this fact support the need for the concept of resonance Borazine (B3N3H6) has often been called inorganic benzene. Draw Lewis structures for borazine. Borazine is a six-membered ring of alternating boron and nitrogen atoms. 

A modification of the standard CNDO/2 MO calculation, in which pairs of atoms associated with the same or different molecules are differentiated, leads to reasonable results for 7r-7r-type molecular complexes.294 It was suggested that benzene-borazine (stabilization energy 2—5 kcal mol-1) and borazine-borazine (5—18 kcal mol ) can exist in the ground state, the molecules being arranged symmetrically in parallel planes. 

Borazine (BsNsHg) has often been called inorganic benzene. Draw Lewis structures for borazine. Borazine is a six-membered ring of alternating boron and nitrogen atoms. 

There are similar analogues to other aliphatic hydrocarbons, for example HjN BHj, which is isoelectronic with ethene, and a most interesting compound called borazine, B3N3H6, which possesses physical properties remarkably like those of the aromatic analogue ... 

Borax stability Boraz anaphthalene Borazine [6569-51-3] Boraz ines Borazon... 

The emphasis in the approaches to boron nitride [10043-11 -5] BN, precursors has been concentrated on cycHc compounds. There have been recent reports of trimethylsilyl-substituted aminoboranes being evaluated as B—N precursors. These are linear borylamines containing up to four boron atoms. Compounds were also synthesized with free —NH2 groups amenable to condensation with either dihaloboranes or dihaloborazines (65) and offering suitable monomers for linear B—N polymer synthesis and borazine-ring-linking appHcations. 

This works well for all nido- and arachno-boranes but not for the c/o o-dianions, which are much less reactive. Reactions of B2H6 with NH3 are complex and, depending on the conditions, yield aminodiborane, H2B(/r-H)(/r-NH2)BH2, or the diammoniate of diborane, [BH2(NH3)2]-[BH4] (p. 165) at higher temperatures the benzene analogue borazine, (HNBH)3, results (see p. 210). 

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) ... 

Numerous other reactions have been documented, most of which are initiated by nucleophilic attack on B. There is no evidence that electrophilic substitution of the borazine ring occurs and conditions required for such reactions in benzenoid systems disrupt the borazine ring by oxidation or solvolysis. However, it is known that the less-reactive hexamethyl derivative B3N3Mee (which can be heated to 460° for 3 h without significant decomposition)... 

IV-substituted and B-substituted borazines are readily prepared by suitable choice of amine and borane starting materials or by subsequent reaction of other borazines with Grignard reagents, etc. Thermolysis of monocyclic borazines leads to polymeric materials and to polyborazine analogues of naphthalene, biphenyl, etc. ... 

Borazine, (HBNH)3, analogous to benzene prepared by A. Stock and E. Pohland. 

The aromaticity of such inorganic ring systems as borazine, the phosphonitrilic halides (69), and the thiazyl halides (70) has been studied extensively from a theoretical viewpoint. ... 

B-C bonds, 3, 97 B-N bonds, 3, 97 B-O bonds, 3,94 B-P bonds, 3, 97 B-Si bonds, 3, 97 oxo acid anion complexes, 3, 96 Borates, alkoxo-, 3, 94 Borates, amidotrihydro-, 3,92 Borates, aryloxo-, 3, 94 Borates, carboxylato-, 3,96 Borates, catechol, 3,95 Borates, chlorosulfato-, 3,97 Borates, dicarboxylato-, 3,96 Borates, dipyrazol-l-yl-, 3, 92 Borates, halogeno-, 3,92 Borates, halogenohydro-, 3,90 Borates, hydro-, 3,90 Borates, hydrohydroxo-, 3,90 Borates, hydropyrazol-l-yl-, 3, 92 Borates, hydroxo-, 3,94 Borates, hydroxycarboxylato-, 3,96 Borates, inositol, 3, 95 Borates, monoalkyl-, 3, 92 Borates, monophosphido-, 3, 92 Borates, peroxohydroxo-, 3, 94 Borates, polyol, 3, 95 Borates, pyrrol-l-yl-, 3, 92 Borates, sulfato-, 3, 97 Borates, tetrabromo-, 3, 92 Borates, tetrachloro-, 3, 92 Borates, tetrafluoro-, 3, 92 minerals, 6, 847 Borates, tetrahalogeno-mixed, 3, 93 nB NMR, 3, 92 Borates, tetraiodo-, 3, 92 Borates, tetranitrato-, 3, 96 Borates, tetraperchlorato-, 3, 97 Borates, tripyrazol-l-yl-, 3, 92 Borax, 3,101 Borazines... 

Borazine, B3N3Hft, a compound that has been called inorganic benzene because of its similar hexagonal structure (but with alternating B and N atoms in place of C atoms), is the basis of a large class of boron—nitrogen compounds. Write its Lewis structure and predict the composition of the hybrid orbitals used by each B and N atom. 

Another useful deposition reaction is the decomposition of borazine. This is a condensation reaction which produces an amorphous BN with residual hydrogen incorporation ]... 

One of the first reports related to the preparation of macrocyclic ring systems with boron atoms deals with the transformation of m-difunctionalized borazines into cyclic di-, tetra-, or hexaborazines [16-19]. 

The cyclic dimeric borazine derivatives 2 and 3 can be prepared by reaction of 2,4-dichloro-l,3,5,6-tetramethylborazine with aromatic 1,3-dihydroxy and l-amino-3-hydroxy compounds (Fig. 2). The products are obtained in yields... 

By reaction of 2-alkyl-4,6-dichloro-l,3,5-trimethylborazines (alkyl = methyl, ethyl, i-propyl) with bis(trimethylsilyl)amine the tetrameric borazine ring systems 4-6 are produced (Fig. 2) they can be purified by several successive vacuum sublimations (yields 4-60%). If the borazines carry n-propyl and tert-butyl groups in the 2-position or if methylbis(trimethylsilyl)amine is used to bridge the borazine molecules, the macrocyclic ring formation is inhibited [17, 18]. 

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