The Synthesis And Controlled Drug Delivery Study Of MOFs With N-, O-containing Ligands

Metal-organic-frameworks (MOFs) as a kind of new material belonging to coordination chemistry field have attracted considerable attention and developed rapidly owing to not only their intriguing structures but also their various potential applications, such as drug deliver, catalysis, biosensor, gas storage, luminescence. And choosing and designing suitable organic ligands is the key factor to obtain materials with prospective properties. In this paper, aiming to obtain MOFs with intriguing structures and specific application, we selected flexible ligand Hpypymba which contains pyridine and pyrazine N-heterocycle, and rigid ligand tta with multi-carboxyl as the building blocks to construct coordination complexes with multiple transition metal ions(Cu(Ⅱ), Co(Ⅱ), Cd(Ⅱ)). X-single crystal diffraction has been used to analyse the structures of synthesized complexes and thermogravimetric analysis, infrared analysis, fluorescence, elemental analysis as well as relative properties for compounds also have been measured afterwards.Four coordination compounds have been synthesized by hierarchical diffusion method and hydrothermal method respectively. They are named as [Cu2(pypymba)3]n (1), [Cu2(pypymba)4]n (2), [Co2(pypymba)4]n (3),{[Cd1.5(tta)(H2O)4.5]· H2O}n (4). X-single crystal diffraction indicates that complex 1 is connected by Cu-O coordination bonds and forms an infinite 1D helix-chain, then its crystalline structure is extended to 3D network(porosity by 21.3%) with the combined effects of C-H…O hydrogen bonds and π-π interactions. However, compared to 1,2 and 3 exhibit a 3D supramolecular network,connected only by hydrogen bond andπ-π interactions without coordination bond. In the structure of compound 4, Cd-O coordination bond plays an important role that constructs a 2D plane structure by itself, and the 3D structure with a porosity 27.3% is formed by the effect of hydrogen bonds between coordinated water molecules and articulated skeleton.Meanwhile, we have investigated the superoxide dismutase mimetic activities(SOD) of complexes 1 and 2, and the controlled drug delivery of Ibuprofen for complex 4 also was studied in this paper. The result of SOD-like activities revealed that both 1 and 2 exhibited a good ability to inhibit the oxidation of pyrogallol, and the IC50(the inhibition ratio of 50%) values respectively are 24.2μg/mL and 37.5μg/mL.Drug-loaded research for Ibuprofen indicated that complex 4 reached a maximal Ibuprofen loading(0.203 g(Ibu)/g(MOFs)) after 5 days with a mass ratio 1:1 for 4 and Ibuprofen solution. After then, drug deliverd research demonstrated a slow delivery for Ibuprofen in PBS buffer solution,57.6% after 72 hours.