Syntheses, structures and properties of two manganese(II) metal–organic frameworks based on bromoisophthalate and bipyridyl-type co-ligands

Two new manganese(II) coordination polymers, [Mn2(bpe)2(4-Brip)2]n (1) and {[Mn3(H2O)2(H-bpp)2(5-Brip)4]·H2O}n (2), were prepared through hydrothermal reactions of Mn(II) acetate with H2-4-Brip or H2-5-Brip (H2-4/5-Brip = 4/5-bromoisopthaliac acid) and the bipyridyl-type co-ligands bpe or bpp (bpe = 1,2-bi(4-pyridyl)ethane and bpp = 1,3-bi(4-pyridyl)propane). The two complexes were characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis and X-ray single-crystal diffraction. Complex 1 has a complicated (3,5)-connected 3D 3-fold interpenetrating network with a Schläfli symbol of (42.65.83)(42.6), constructed of the ribbon-like chains having dimeric [Mn(COO)]2 units bridged by 4-Brip. Complex 2 contains isophthalato-bridged trimanganese clusters as building units, which are linked by 5-Brip anions to form a 1D ladder-like chain with unidentate coordinated H-bpp decorated as pendants. And the chains are further linked by Nsingle bondH∙∙∙O and Osingle bondH∙∙∙O hydrogen bonding to generate a 2D interlocked architecture. Dominant antiferromagnetic couplings were observed in complexes 1 and 2.