Multidimensional Metal−Organic Frameworks Constructed from Flexible Bis(imidazole) Ligands

Two structurally related flexible bis(imidazole) ligands, N,N ‘ -(1,1-methyl)bis(imidazole) ( L 1 ) and N, N ‘-(1,4-butanediyl)bis(imidazole) ( L 2 ) reacted with Ag I, Cu II, Zn II, and Cd II salts under hydrothermal conditions (except for 2 at room temperature), resulted in the formation of eight novel metal−organic coordination architectures, from one-dimensional (1D) chain to three-dimensional (3D) network structures: {[Ag( L 1 ) 2 ]ClO 4 } n ( 1 ), {[Cu( L 1 ) 2 (H 2 O) 2 ]Cl 2 (H 2 O) 0.5 (acetone)} n ( 2 ), {[Cu( L 1 ) 2 ](BF 4 ) 2 } n ( 3 ), {[Cu( L 1 ) 2 ](ClO 4 ) 2 } n ( 4 ), {[Zn( L 1 ) 3 ](ClO 4 ) 2 } n ( 5 ), {[Cd( L 1 ) 3 ](ClO 4 ) 2 } n ( 6 ), {[Cd( L 1 ) 2 ](N 3 ) 2 } n ( 7 ), and {[Zn( L 2 ) 2 ](ClO 4 ) 2 } n ( 8 ). All complexes have been structurally characterized by X-ray diffraction analysis. In 1, the Ag I centers are two-coordinate with linear geometry and L 1 ligands bridge the Ag I centers to form 1D single helical chains. 2 and 7 have 1D double chain structures with the central metal ions being six-coordinated by four discrete L 1 and two apical ligands (water molecules for 2 and N 3 - for 7 ). 3 and 4 are isostructural two-dimensional (2D) (4,4) networks with square planar Cu II centers. 5 and 6 also are isostructural with CdSO 4 -like 3D framework structures. In 8, the Zn II ions are tetrahedral, and each L 2 ligand links two Zn II ions to form a 1D double chain.