Anion-dependent construction of a series of fluorescent coordination polymers based on 1D zinc∧4,4′-bis(imidazol-1-yl)-biphenyl substrates

In this work, the rod-like ligand 4,4'-bis(imidazol-l-yl)-biphenyl (bibp) has been utilized as a building block to carry out counterion effects on the structural diversities of coordination polymers. A series of new zinc complexes, [Zn(trans-bibp)Cl-2](infinity) (1), [Zn(trans-bibp)Br-2](infinity) (2), {[Zn(cis-bibp)(Ac)(2)]center dot(H2O)}(infinity) (3), [Zn(trans-bibp)SO4](infinity) (4), {[Zn-2(cis-bibp)(2)(iPa)(2)]center dot(H2O)}(infinity), (5, H(2)ipa=isophthalic acid) and {[Zn (trans-bibp)(cis-bibp)]center dot(ClO4)(2)(CHCl3)(2)(CH3OH)}(infinity) (6) have been successfully synthesized. Complexes 1 and 2 are iso-structural, which show a 1D W-type chain [Zn(trans-bibp)](infinity). Complex 3 exhibits a 2D wave-like layer formed by the hydrogen bond among the 1D linear chain [Zn(cis-bibp)](infinity). Complex 4 displays a 2D fish-bone lattice, which is generated from connecting the 1D W-type chain [Zn(trans-bibP)](infinity) by the mu(2)-SO42-. Complex 5 presents an interesting 2D-3D 6(5).8 architecture, including two 1D chains [Zn(ipa)](infinity) and [Zn(cis-bibp)](infinity). Complex 6 demonstrates a 2D wave-like layer [Zn(trans-bibp)(cis-bibp)](infinity). The structural diversities among 1-6 have been carefully discussed, and the role of counterion in the self-assembly of coordination polymer have also been well documented from the coordination affinity and bridging mode. Furthermore, the solid-state fluorescence properties of 1-6 at room temperature have been studied. (C) 2015 Elsevier Inc. All rights reserved.