Ligand geometry-directed assembly of seven entangled coordination polymers

Abstract

Seven new complexes [Cd(oba)(2,2′-bipy)]₂ (1), [Co(oba)(bbm)]·1.5H₂O (2), [Mn₃(oba)₃(bbm)(H₂O)₂]·DMF·2H₂O (3), [Mn₂(bibm)₂(oba)₂] (4), [Co(oba)(bibm)]₂·H₂O (5), [Co₅(bpb)₃(oba)₄(Hoba)₂(H₂O)₂] (6) and [Ni₂(bpb)₂(oba)₂(DMF)(H₂O)]₂·5H₂O (7) (H₂oba = 4,4′-oxydibenzoic acid, bbm = 1,4-di(1H-imidazol-1-yl)benzene, bibm = 4,4′-di(1H-imidazol-1-yl)-1,1′-biphenyl, bpb = 1,4-di(pyridin-4-yl)benzene, 2,2′-bipy = 2,2′-bipyridine) have been synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, X-ray powder diffraction and X-ray single crystal diffraction. Compound 1 displays a 3-fold polythreaded 2D network, while 2 has sql layers and these layers are further stacked in a 2D → 3D polycatenation model. Compound 3 shows a 3D porous net with {4²¹·5⁴·6³} topology with 1D channels that are filled by DMF and water molecules while 4 possesses a 2D (4,4) layer structure composed of [Mn₂(bibm)₂(oba)₂] units. Compound 5 exhibits a five-fold interpenetrating 3D framework while 6 displays a 2D → 3D polycatenation motif. Compound 7 has a three-fold interpenetrating 3D framework. These results provide some insight into the ligand geometry-driven assembly of entangled coordination polymers. Thermal stability and photoluminescence properties of 1–7 were studied. The optical and photocatalytic properties of 3 and 6 were also investigated.