Benzene borazine

The inorganic benzene borazine has been shown to undergo electrophilic substitution in a manner very similar to benzene itself. Does the electrophile attack at or N Use orbital interaction theory to predict the site of attack. Compare this with the prediction on the basis of an SHMO calculation and experimental findings (Chia-varino, B. Crestoni, M. E. Di Marzio, A. Fomarini, S. Rosi, M., J. Am. Chem. Soc., 1999,121, 11204-11210). 

IF the product were a monomer, its structure could be drawn as Cl2PsN, which is analogous to organic nitriles. R—C=N. For this reason the original names used for these compounds were phosphonitriles, phosphonitrilic chloride, etc. However, the products are actually either cyclic or linear polymers of general formula [NPC ,] . Thus, by analogy with benzene, borazine. etc., these compounds hove become known as phosphazenes. The rn jor product of the reaction in Eq. 16.47 and the easiest to... 

The most important ring system of organic chemistry is the benzene ring, either as a separate entity or in polynuclear hydrocarbons such as naphthalene, anthracene, and phenanthrene. Inorganic chemistry has two (at least) analogues of benzene borazines. trimeric cyclophosphazene compounds, PjNjX,. ... 

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. 

Each of the following contains a 6-membered ring benzene, borazine (see Figure 13.21), pyridine and S5 (see Box 1.1). Explain wby only benzene contains a 6-fold principal rotation axis. 

Borazine, B3N3H6 is often referred to as inorganic benzene because of its similar structure. Like benzene, borazine has a delocalized 77 system. Describe the molecular orbitals of the 77 system. Identify the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). How many nodes does the LUMO possess ... 

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