Two　three-dimensional　(3-D)　MOFs,　[(C2H5)(4)N](3)[H3O](2)[Cd6Br(H-2-DHBDC)(8)(DMF)(4)]　(1;　H-4-DHBDC=2,5-dihydroxy-1,4-benzenedicarboxylic　acid,　DMF=N,N-dimethylformamide)　and　[(CH3)(2)NH2](2)Cd-3(H-2-DHBDC)(4)(DMF)(2)]center　dot　2DMF(2),　are　prepared　from　the　self-assembly　reactions　between　Cd(CH3COO)(2)　and　H-4-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　H-2-DHBDC　ligands.　The　photo　luminescent　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.　(C)　2015　Elsevier　Inc.　All　rights　reserved.