Three interdigitated metal–quinolone complexes from self-assembly of mixed ligands and cadmium salts

Abstract Three interdigitated metal–quinolone complexes, [Cd 2 (cfH) 2 (btec)(H 2 O) 2 ]·6H 2 O ( 1 ), [Cd 2 (ppaH) 2 (1,3-bdc) 2 ]·4.25H 2 O ( 2 ) and [Cd 2 (LevofH)(1,3-bdc) 2 (H 2 O) 2 ] ( 3 ) (cfH = ciprofloxacin, ppaH = pipemidic acid, LevofH = levofloxacin, btec = 1,2,4,5-benzenetetracarboxylate, 1,3-bdc = 1,3-benzenedicarboxylate) have been synthesized and characterized by elemental analyses, IR spectra, X-ray powder diffractions, TG analyses and single crystal X-ray diffraction. Compound 1 exhibits a (2D → 3D) interdigitated architecture that is first assembled from 2D wavelike (6,3) nets with side arms. Compound 2 is the first example of (2D → 3D) interdigitated metal–ppaH complex, which is constructed from sidearm-containing 2D layers of (4,4) topology. Compound 3 is built from 1D double chains with dangling levofloxacin ligands protruding from one side of the chain, and each pair of these double chains are interdigitated with each other to generate a perfect molecular zipper. By inspection of the structures of 1 – 3 , it is believed that the short aromatic polycarboxylate ligands are important for the construction of interdigitated metal–quinolone complexes. The photoluminescent properties of compounds 1 – 3 have also been investigated.