Four complexes with a bulky carboxylate ligand: syntheses, crystal structures, and luminescent properties

Four complexes of 3,3-diphenylpropanoate (L) and 4,4'-bipyridine as auxiliary bridging ligands were synthesized and characterized, namely [Zn(L)(2)(4bpy)-( EtOH)(2)](infinity) (1), [Co(L)(2)(4bpy)(EtOH)(2)](infinity) (2), [Ni(L)(2)(4bpy)-( EtOH)(2)](infinity) (3), and [Cu(L)(2)(4bpy)(H2O)](infinity) (4) (4bpy = 4,4'-bipyridine). X-ray single-crystal diffraction analyses show that complexes 1-4 all take one-dimensional (1D) fishbone-like structures incorporating bridging 4bpy ligands. The complexes show different supramolecular frameworks interlinked via intermolecular hydrogen bonds, pi center dot center dot center dot pi stacking, and/or C-H center dot center dot center dot pi supramolecular interactions. Complex 3 only has a simple one-dimensional fishbone-like chain, whereas complexes 1 and 2 show two-dimensional supramolecular structures by interchain C-H center dot center dot center dot O hydrogen bonds. Complex 4 is assembled into two-dimensional layers and then an overall three-dimensional framework by a combination of interchain O-H center dot center dot center dot O hydrogen bonds and C-H center dot center dot center dot pi supramolecular interactions. The luminescent properties of the ligands and their complexes were investigated.