The ground-state stabilization of the keto tautomer of 7-hydroxyquinoline in methanol/argon matrices at 10 K

The stabilization of the ground-state keto tautomer of 7-hydroxyquinoline (7HQ) has been observed in methanol/argon mixed matrices at 10 K. The stabilized tautomer has been ascribed to the isolated 7HQ-(MeOH)2 bridged complex based on the observation that the open-chain methanol dimer concentration reaches a maximum concomitantly with the fluorescence excitation spectrum of the keto tautomer centered at 420 nm. Also discussed are the excited-state proton-transfer processes for the 7HQ-methanol unbridged complexes.