Malen Bara CHEMISTRY   -   Organic Chemistry

Which of the following compounds is not aromatic?

Benzene, pyridine, and naphthalene all obey Huckel's rule for aromaticity, possessing (4n+2) π-electrons and a planar structure. Cyclooctatetraene, however, does not adopt a planar conformation and does not have (4n+2) π-electrons, making it non-aromatic.
Which of the following statements about the polymerization of ethylene to form polyethylene is correct? Which of the following functional groups can act as both an acid and a base? In proton NMR spectroscopy, what splitting pattern would you expect for the protons on the methylene group in ethyl acetate (CH3COOCH2CH3)? Which of the following heterocycles contains nitrogen and is aromatic? Which of the following compounds is not aromatic? Which of the following statements about the bonding in ethyne (acetylene, C2H2) is correct? Which of the following compounds is chiral? In an electrophilic aromatic substitution reaction, which intermediate is formed? Which of the following principles is not one of the Twelve Principles of Green Chemistry? What is the first step in the retrosynthetic analysis of 1-bromo-2-phenylethane? Which type of enzyme catalysis involves the formation of a covalent bond between the enzyme and the substrate? In which of the following reactions does the formation of a carbocation intermediate occur?