The reaction of l2 with Na11BH4 yields a gaseous product with an empirical formula of BH3. a) Draw the structure of the gaseous product. b) Predict the 11B NMR spectrum of the product and hence state how it differs from the spectrum that would be expected for monomer BH3. c) The 'H NMR spectrum of the product gives two signals. One signal is a septet of quintets and the septet has a relative intensity of 1:2:3:4:3:2:1. This signal may be assigned to a proton environment which is not explained by valence bond theory. [For 1"B: I = 3/2]. i) Identify this proton environment and explain why it is unusual. How may the bonding be explained? ii) Explain why the 1:2:3:4:3:2:1 relative intensity in the NMR signal is so diagnostic of the unusual environment

The reaction of l2 with Na11BH4 yields a gaseous product with an empirical formula of BH3. a) Draw the structure of the gaseous product. b) Predict the 11B NMR spectrum of the product and hence state how it differs from the spectrum that would be expected for monomer BH3. c) The 'H NMR spectrum of the product gives two signals. One signal is a septet of quintets and the septet has a relative intensity of 1:2:3:4:3:2:1. This signal may be assigned to a proton environment which is not explained by valence bond theory. [For 1"B: I = 3/2]. i) Identify this proton environment and explain why it is unusual. How may the bonding be explained? ii) Explain why the 1:2:3:4:3:2:1 relative intensity in the NMR signal is so diagnostic of the unusual environment

Organic Chemistry

8th Edition

ISBN:9781305580350

Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote

Publisher:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote

Chapter21: Benzene And The Concept Of Aromaticity

Section: Chapter Questions

Problem 21.26P: Compound I (C11H14O2) is insoluble in water, aqueous acid, and aqueous NaHCO3, but dissolves readily...

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