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)](infinity) (1), {[Zn(ndc)(H2O)](H2O)}(infinity) (2), {[Ag-2(ndc)(4bpy)(2)][Ag(4bpy)(H2O)](ClO4)(H2O)(2)}(infinity) (3), [Zn-5(ndc)(4)(4bpy)(2)(mu(3)-OH)(2)](infinity) (4), {[Ag(ndc)(abp)][Ag(abp)](H2O)(3)}(infinity) (5), and {[Zn-2(ndc)(2)(abp)(H2O)(2)](H2O)(2)}(infinity) (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 angstrom) 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 63 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 p-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.