Divalent copper and zinc complex based on a new 4,4′-bis-[(dicarboxymethyl)aminomethyl]biphenyl and N-donor ligands: Syntheses, structures and photoluminescence

Seven new coordination compounds, namely, [Cu2(L)(H2O)4]·4H2O (1), [Cu4(L)2(phen)4]·15H2O (2), [Cu2(L)(Him)4]·4H2O (3), [Cu4(L)2(pbib)2(H2O)4]·8H2O (4), [Zn2(L)(pbib)2]·8H2O (5), [Zn2(L)(biim-4)2]·5H2O (6) and [Zn2(L)(biim-4)]·3H2O (7), where biim-4 = 1,1′-(1,4-butanediyl)bis(imidazole), pbib = 1,4-bis(imidazol-1-ylmethyl)benzene, phen = 1,10-phenanthroline, Him = imidazole and H4L = 4,4′-bis-[(dicarboxymethyl)aminomethyl]biphenyl, have been synthesized by Cu(II) and Zn(II) salts with L anions and N-donor ligands. These compounds were characterized by single-crystal X-ray diffraction analyses and further identified by infrared spectra (IR), elemental analyses, powder X-ray diffraction (PXRD) analyses and thermogravimetric analyses (TG). Compounds 1–3 show zero-dimensional (0D) structures. In compounds 1 and 2, the discrete structures are further linked by intermolecular hydrogen-bonding and π–π interactions to form a two-dimensional (2D) supramolecular layer, respectively. Moreover, in compound 3, the discrete structure is further extended by intermolecular hydrogen-bonding interactions to yield a 3D supramolecular architecture. Compound 4 displays a tetranuclear structure, which is further connected by intermolecular hydrogen-bonding interactions to form a 3D supramolecular structure. Compound 5 shows a 3D 5-fold interpenetrating diamond framework. Compound 6 reveals a 2D 63-hcb network. Compound 7 shows a 3D 6-connected net with the (411·64) topology. In addition, the luminescent properties of 5–7 have also been investigated in details.

Graphical abstractSeven copper(II) and zinc(II) coordination compounds based on the H4L ligand and different N-donor ligands have been prepared, and the luminescent properties for 5–7 have been studied in solid state at room temperature.Figure optionsDownload full-size imageDownload as PowerPoint slide