Molecular ladders with multiple interpenetration of the lateral arms into the squares of adjacent ladders observed for [M2(4,4′-bpy)3(H2O)2(phba)2](NO3)2•4H2O (M = Cu2+ or Co2+; 4,4′-bpy=4,4′-bipyridine; phba=4-hydroxybenzoate)

isomorphous molecular ladders formulated as [M-2- (4,4'-bpy)(3)(phba)(2)(H2O)(2)](NO3)(2). 4H(2)O (4,4'-bpy = 4,4'-bipyridine; phba = 4-hydroxybenzoate; M = Cu2+ Or Co2+), shown by X-ray, feature a novel ladder motif having different inner rungs (4,4'-bpy) and lateral arms (phba). Penetration of the lateral arms into the squares of adjacent ladders results in a novel 3-D network.