Lack of intramolecular hydrogen bonding in glucopyranose: Vicinal hydroxyl groups exhibit negative cooperativity

The hydroxyl groups of d-glucopyranose in the gas-phase do not form a cooperative network of intramolecular hydrogen bonds but rather show negative cooperativity as evidenced by changes in O-H bond lengths, stretching frequencies, antibonding orbital occupancies and orbital overlap integrals, indicating a net repulsive rather than an attractive interaction.