Ag(I) and Zn(II) coordination polymers with a bulky naphthalene-based dicarboxyl tecton and different 4,4'-bipyridyl-like bridging co-ligands: structural regulation and properties

A series of six Ag(I) and Zn(II) coordination polymers, namely, Ag(2)(ndc)](∞) (1), {Zn(ndc)(H(2)O)](H(2)O)}(∞) (2), {Ag(2)(ndc)(4bpy)(2)]Ag(4bpy)(H(2)O)](ClO(4))(H(2)O)(2)}(∞) (3), Zn(5)(ndc)(4)(4bpy)(2)(μ(3)-OH)(2)](∞) (4), {Ag(ndc)(abp)]Ag(abp)](H(2)O)(3)}(∞) (5), and {Zn(2)(ndc)(2)(abp)(H(2)O)(2)](H(2)O)(2)}(∞) (6), have been prepared by using 2,3-naphthalenedicarboxylic acid (H(2)ndc), an analogue of 1,2-benzenedicarboxylic acid (H(2)bdc), and different 4,4'-bipyridyl-like bridging co-ligands 4,4'-bipyridine (4bpy) and trans-4,4'-azobis(pyridine) (abp). The initial complexes 1 and 2 display the unusual two-dimensional (2-D) five-connected (4(8).6(2)) and the 2-D three-connected (4.8(2)) coordination networks, respectively. When two comparable rod-like linkers 4bpy and abp (with different N,N'-donor separations of the molecular backbones of ca. 7 and 9 ?) are further introduced, two one-dimensional (1-D) complexes 3 and 5, a three-dimensional (3-D) coordination framework 4 with (4(3))(4(3).6(3))(4(3).6(5).8(2))(4(4).6(4).8(2))(4(10).6(5)) topology and a 2-D 6(3) layered coordination polymer 6 are constructed. A structural comparison of these complexes with those based on the structurally related bdc ligand suggests that the extended π-conjugated system of ndc with different electronic nature and steric bulk play an important role in constructing the supramolecular architectures for 1-6, which are also regulated by different bridging N-donor co-ligands and metal ions. Moreover, complexes 1-6 show strong solid-state luminescence emissions at room temperature that mainly originate from the intraligand transitions of ndc.