Tropolone is a sensitive reagent for reducing sugars. A non-benzenoid aromatic compound, Reagent for the preparation of fused heterocycles and complexes of Ga(III) and In(III).
Purification Methods
Crystallise tropolone from hexane or pet ether and sublime it at 40o/4mm. Also distil it at high vacuum. [Beilstein 8 IV 159.]
structure and hydrogen bonding
The tropolone has a simple structure consisting of a seven-membered carbon ring. The pi electrons present in the ring are delocalised. A ketone grouped to the first carbon, and an hydroxyl group attached to the second carbon. Tropolone, C7H6O2, crystallizes in space group P21/c, with a = 7.135, b = 12.178, c = 7.122Å, β = 99.63 ° and Z = 4. The molecule is essentially planar and exhibits slight bond alternation in the seven-membered ring. The hydroxyl group makes a bifurcated hydrogen bond with carbonyl oxygen atoms, of which one branch is intramolecular and the other intermolecular. The latter intermolecular branches form a hydrogen-bonded dimer. These characteristic hydrogen bonds seem to play a role in increasing the contribution from the dipolar ionic forms to the ground state of the tropolone molecule.