Assembly and photocatalysis of three novel metal–organic frameworks tuned by metal polymeric motifs

By using a thiodiacetate, phenanthroline and tuning the metal salts in the reaction system, three new metal-organic coordination complexes, {[Co(MOPIP)₂(tda)]·H₂O}_1∕2 (1), [Cd(MOPIP)₂(tda)]₂·3H₂O (2) and [Cu₅I₄(MOPIP)₃·H₂O]_n (3) (tda = S(CH₂COO)₂²⁻, thiodiacetate; MOPIP = 2-(4-methoxyphenyl)-1H-imidazo[4,5-f][1,10]phenanthroline), have been prepared through hydrothermal reactions. In 1 and 2, the metal (Co²⁺/Cd²⁺) centers are connected by tda to form a mononuclear molecule, which connect to a two-dimensional (2D) layer by N-H···O hydrogen bonds. By selecting the copper iodide salt we get 3, where the Cu⁺ center exhibits three different coordination types, which has never been seen before in the same compound, and linked by iodide and MOPIP to construct a new 3D framework. 3 represents the first example of MOPIP showing a new coordination mode with four nitrogens all coordinated. The metal salts play an important role in assembly of the structures of 1-3. Introduction of MOPIP shows significant effect on the dimensionalities of complexes. The fluorescence and catalytic properties of 1 and 3 have also been investigated.