Syntheses, Structures, and Luminescent Properties of a Series of Coordination Compounds Based on (4-Carboxylphenyl) (4-(2′-Carboxylphenyl)benzyl) Ether and Different N-Donor Ligands

Fourteen novel coordination compounds based on (4-carboxylphenyl) (4-(2'-carboxylphenyl)benzyl) ether (H2L) and different N-donor ligands have been hydrothermally synthesized and structurally determined by single-crystal X-ray diffraction analyses, namely, [Zn-3(L)(3)(biim-4)(2)]center dot H2O (1), [Cd(L)(H2O)(brim-4)(0.5)] (2), [Zn(L)(BIE)] (3), [Co(L)(BIE)] (4), [Cd(L)(BIE)] (5), [Ni(L)(BIE)] (6), [Ni(L)(phen)]center dot H2O (7), [Co(L)(phen)]center dot H2O (8), [Co(HL)(2)(phen)(2)]center dot 3H(2)O (9), [Cd(L)(H2O)(phen)] (10), [Co(L)(H2O)(phen)] (11), [Cd(L)(phen)(2)] (12), [Pb(L)] (13), and [Pb(L)(phen)]center dot H2O (14), where binn-4 = 1,1'-(1,4-butanediyl)bis(imidazole), BIE = 2,2'-bis(1H-imidazolyl)ether, and phen = 1,10-phenanthroline. Compound 1 displays an unusual three-dimensional (3D) binodal (4,5)-connected net with a point symbol of (4(3).6(2)-8)(4(5).5.6(4)). Compound 2 exhibits one-dimensional (ID) looplike chain structures, which are further extended into a 3D supramolecular architecture through pi-pi interactions. Compounds 3-6 are isomorphous and feature similar two-dimensional (2D) layer structures. Compounds 7 and 8 are isomorphous and show the same zero-dimensional (OD) structures, which are further extended by pi-pi interactions into 2D supramolecular layers. Compound 9 displays a discrete [Co-2(L)(2)(phen)(2)] dimer. Neighboring dimers are further linked by pi-pi interactions to form a ID double chain. Compounds 10 and 11 exhibit similar ID double chain structures. The chains are further linked via pi-pi interactions to generate 2D supramolecular layers. Compound 12 shows a discrete [Cd-2(L)(2)(phen)(2)] dimer. The pi-pi stacking and hydrogen-bonding interactions further extend the dimers into a 3D supramolecular architecture. Compound 13 displays a typical (4(4))-sql network structure. Neighboring networks are further linked by the pi-pi interactions, leading to an unusual 3D supramolecular architecture. Compound 14 exhibits a discrete [Pb-2(L)(2)(phen)(2)] dimer. Neighboring dimers are further linked by the pi-pi interactions to form a 2D supramolecular layer. The thermal stabilities and luminescent properties of the complexes have also been investigated in detail.