Mass- and isomer-selected S-1<-- S-0 resonant two-photon ionization and S-1--> S-0 fluorescence spectra were obtained for the supersonically cooled 7-hydroxyquinoline .(NH3)(n) clusters with n=2-16. For n=2 and 3, the absorption and emission spectra exhibit discrete and narrow bands, characteristic of nonreactive hydrogen bonded ammonia-chain clusters. For n greater than or equal to 4, the S-1<-- S-0 R2PI spectra are completely broadened, with an onset at approximate to 355 nm. For n=4-7, a weak fluorescence emission is observed, Stokes-shifted by approximate to 185 nm, with a maximum at approximate to 540 nm, which shows discrete structure on a broad background. From comparison to fluorescence emission observed in bulk solution, we conclude that S-1 state enol --> keto tautomerization occurs. For the n greater than or equal to 7 or 8 clusters, the fluorescence emission spectra become completely unstructured and shift to the blue, peaking at 435-450 nm. This emission indicates the occurrence of either S-1-state proton transfer to the ammonia solvent cluster and formation of the 7-HQ anion, or of the ground-state intracluster enol --> keto tautomerization reaction.