Mn(II)-Binaphthalenyl Dicarboxylate Complexes: Helical Rectangular Tubes, (4,4) Grid Chiral Layer and Three-Dimensional Cubic Diamond Frameworks

Abstract

Reactions of 2,2′-dihydroxyl-[1,1′]-binaphthalene-3,3′-dicarboxylate acid (H2bna) with manganese chloride by a solvent or solvothermal method in the presence of pyridine (py) or 4-picoline (pic) give birth to three 1D to 3D frameworks: [Mn(bna)(DMF)2(H2O)2]n·nDMF (1), {(Hpic)2[Mn3(bna)4(C2H5OH)2(H2O)2]·5H2O}n (2), and {(Hpy)2[Mn3(bna)4(py)2(H2O)2]·4H2O}n (3) (DMF = N,N′-dimethylformamide). Crystal structure analyses reveal that 1 is a mesomer with equivalent R- and L-helical rectangular tubes constructed from homochiral ligands, which is further assembled into a 3D supramolecular network through hydrogen bonds and C−H···π interactions. Complex 2 consists of a (4,4) grid chiral layer structure, while 3 features a 3D cubic diamond network with Schlafli symbol 66 topology, though they both comprise of [Mn3(μ2-COO)6(COO)2] pinwheel molecular building blocks which act as 4-connected nodes and bna2− as linkers. Magnetic studies indicate that antiferromagnetic couplings exist in both 2 and 3.