Four novel topological frameworks based on 4,4′-(hexafluoroisopropylidene)diphthalic acid and 1,1′-(1,4-butanediyl)bis(imidazole) ligand

Abstract

Four new coordination polymers, constructed from 4,4′-(hexafluoroisopropylidene)diphthalic acid (H₄L) and 1,1′-(1,4-butanediyl)bis(imidazole) (biim-4) ligand, have been synthesized: [Cd(HL)(Hbiim-4)(biim-4)_0.5(H₂O)]·2H₂O (1), [Cd₂(L)(biim-4)_0.5(H₂O)₂]·0.5H₂O (2), [Mn₂(L)(biim-4)_0.5(H₂O)₂]·0.5H₂O (3), and [Zn₂(L)(biim-4)_1.5]·(CH₃CH₂OH) (4), where H₄L = 4,4′-(hexafluoroisopropylidene)diphthalic acid, and biim-4 = 1,1′-(1,4-butanediyl)bis(imidazole). Compound 1 displays a 1D chain structure, which is extended by intermolecular hydrogen-bonding interactions to give a novel trinodal (4,5)-connected (4·6⁴·8)(4²·6³·8)(4³·6⁴·8³) topology. Compounds 2 and 3 are nearly isostructural with the same uncommon (5,6)-connected frameworks. Compound 4 shows an unprecedented self-penetrating (4,5)-connected net with Schläfli symbol of (4²·6·7²·8)(6²·7²·8²)(4²·6³·7³·8²). The structural and topological differences of these four compounds indicate that the pH values and the central metals have significant effects on producing novel structures and topologies of the coordination complexes. The thermogravimetric and photoluminescent properties were also investigated for the compounds.