Stimuli-responsive　inorganic-organic　hybrid　metal　halides　(IOMHs)　have　shown　great　potential　in　sensing,　information　encryption　and　anti-counterfeiting,　etc.　However,　the　stimuli-responsive　behavior　based　on　the　regulation　of　the　functional　groups　in　organic　species　is　still　blank　in　IOMHs.　Herein,　three　zero-dimensional　(0-D)　antimony-based　IOMHs　with　different　functional　groups　in　the　organic　cations　are　reported,　namely　[AOEMIm]3SbCl6　(1,　AOEMIm　=　1-acetoxyethyl-3　methylimidazolium),　[HOOCMMIm]3SbCl6·3(OOCMMIm)　(2,　HOOCMMIm　=　1-carboxymethyl-3-methylimidazolium)　and　[HOOCMMIm]3SbCl6　(3).　Photophysical　characterizations　show　that　1,　2　and　3　exhibit　typical　self-trapped　exciton　triplet　broadband　emission,　peaking　at　610,　510　and　525　nm　under　excitation　of　365　nm,　375　nm　and　345　nm,　respectively.　Under　the　H2O　stimulation,　the　organic　groups　in　the　crystal　structures　undergo　a　mutual　transformation,　that　is,　from　acetoxyethyl　or　carboxyl　to　a　mixture　of　carboxyl　and　deprotonated　carboxyl.　Accordingly,　the　organic　group　switching　is　accompanied　by　a　solid-solid　transformation　from　1　or　2　to　3　crystals.　The　intrinsic　mechanism　for　the　phase　transition　is　expounded　as　well.　Due　to　the　obvious　luminescence　change　from　yellow-green　emission　(3)　to　green　emission　(2),　3　is　further　applied　in　the　detection　of　trace　water　in　organic　solvents.　The　water　detection　limit　in　tetrahydrofuran　(THF)　is　as　low　as　0.3%　v/v.　This　study　provides　a　new　avenue　for　the　construction　of　stimuli-responsive　IOMHs.　©　2024　The　Royal　Society　of　Chemistry.