Synthesis And Characterization Of Binaphthol Metal Organic Frameworks

MOFs are organic-inorganic hybrid solids with infinite, uniform framework structuresbuilt from organic linkers and inorganic metal nodes. Because of its unique pore structure andregulatory, these materials have been used in many fields, such as adsorption, separation andpurification, as well as catalysis.In this paper, BINOL-3,3′-dicaboxylic acid (L1) is prepared by3-hydroxy-2-naphthoic acidoxidative coupling under microwave irradiation, using FeCl3·6H2O as catalyst, and thenresolved by L-leucine to give chiral ligand R-3,3’-bicarboxylic-BINOL (R-L1), yield30%;Ligand4,4’-dipyridyl-6,6’-dichloro-2,2’-ethoxy binaphthyl (L2) is synthesized from BINOL,via bromination, hydroxyl protection, chlorination, bromination, and Suzuki reaction, yiels27%; Ligand2,2’-Dihydroxy-1,1’-binaphthalene-6,6’-dicarboxylic acid (L3) is obtained fromBINOL, via bromination, cyanation, and hydrolysis reactions, in35%overall yield. All the3ligands are characterized by IR, NMR.By solution diffusion method, racemic L1coordinate with Cd(II) to give1-D coordinationpolymer [Cd(bna)(DMF)2(H2O)2]n·nDMF MOFs(1). When the second ligand4,4’-bipyridineis added to the system, at the similar condition, R-L1give a chiral2-D sheet[Cd(R-bna)2(bpy)(DMF)2]n MOFs(2). And L3coordinate with Cu2+to give1-D“latticefence”[Cd(dbda)(DMF)]n·nH2O·nCH3OH MOFs(3). All the three MOFs are characterized byXRD, XRPD, TG, IR. By variable temperature X-ray powder diffraction, we determined thethermal stability of MOFs(3), which can fully maintain the frame structure, bond lengths andangles within the range of r.t.~100°C, indicating that the fence type of MOFs(3) structure isdifferent from the others, the frame structure have good thermal stability without guestmolecules in the lattice. This makes it more practical significance.The porous chiral coordination polymer MOFs(2), used as wadding material, is used in liquidphase chromatography to separate racemic compounds. The result shows that MOFs(2)column can well separate racemic1,2-diaminocyclohexane.