Two　new　crystalline　inorganic-organic　hybrid　compounds,　namely,　{[Zn(PCV)(0.5)(BDC)(0.5)]center　dot　3H(2)O}(n)　(1)　and　{[Cd(PCV)(0.5)(BDC)(0.5)(H2O)]center　dot　3H(2)O}(n)　(2)　have　been　solvothermally　synthesized　from　the　1,4-benzenedicarboxylate　(BDC2-)　ligand　and　the　viologen　analog　1-(4-carboxyphenyl)-4,4＇-bipyridinium　(PCV).　In　these　two　compounds,　PCV　ligands　coordinate　with　metal　atoms　to　form　1D　zigzag　chains,　and　the　chains　are　further　bridged　by　the　BDC2-　ligands　to　yield　a　wave-like　layer　with　a　(4,　4)　net　topology.　For　1,　three　layers　interpenetrate　with　each　other　to　construct　a　triple-layer　structure,　which　are　stacked　along　the　b　direction　through　van　der　Waals＇s　force　to　yield　the　final　3D　structure　where　the　channels　along　the　a　direction　host　the　lattice　water　molecules.　In　comparison,　two　layers　interpenetrate　with　each　other　to　construct　a　double-layer　structure,　which　further　interpenetrate　to　form　the　final　3D　structures　where　the　lattice　water　molecules　locate　in　channels　along　a　direction.　Both　compounds　showed　photochromism　accompanied　with　dramatic　decrease　of　photoluminescence　upon　irradiation.　The　powdered　sample　of　1　can　deposit　easily　on　paper　by　diffusing　into　ethanol　solution,　which　displays　the　potential　application　as　an　inkless　and　erasable　print　medium.