Theoretical study of the excited-state proton-transfer threshold in 1-naphthol–ammonia complexes

To help resolve the controversy about the number of ammonia molecules needed to achieve excited-state proton transfer in 1-naphthol–ammonia complexes in the vapour phase, we report the results of ab initio calculations on the structure and energy of complexes with three and four ammonias. Our results indicate that at least four ammonias are needed to produce a stable excited ammonium naphtholate conformer.