Two　three-dimensional　(3-D)　MOFs,　[(C2H5)4N)]3[H3O]2[Cd6Br(H2-DHBDC)8(DMF)4]　(1;　H4-DHBDC=2,5-dihydroxy-1,4-benzenedicarboxylic　acid,　DMF=N,N-dimethylformamide)　and　[(CH3)2NH2]2[Cd3(H2-DHBDC)4(DMF)2]·2DMF(2),　are　prepared　from　the　self-assembly　reactions　between　Cd(CH3COO)2　and　H4-DHBDC,　respectively.　Both　anionic　frameworks　consist　of　linear　trinuclear　Cd　units　(e.g.,　1:　[Cd3BrO2(CO2)7]　and　[Cd3O2(CO2)8];　2:　[Cd3O2(CO2)8])　linked　by　the　H2-DHBDC　ligands.　The　photoluminescent　properties　of　compound　1　are　tunable　through　cation-exchange　with　different　metal　ions.　The　results　demonstrated　an　effective　ion-exchange　approach　toward　the　functional　modification　of　MOF　materials.　©　2015　Elsevier　Inc.　All　rights　reserved.