Structural Diversity in Metal−Organic Frameworks Derived from Binuclear Alkoxo-Bridged Copper(II) Nodes and Pyridyl Linkers

Abstract

New coordination polymers have been obtained by reaction of alkoxo-bridged copper(II) dimers [Cu2(mea)2]2+ and [Cu2(pa)2]2+ (Hmea = monoethanolamine; Hpa = propanolamine) with divergent pyridyl-containing ligands that act as rigid linear exo-bidentate linkers [p-bis(4-pyridyl)benzene, bpbenz, bis(4-pyridyl)acetylene, bpac, 9,10-bis(4-pyridyl)anthracene, bpanth], as a flexible angular exo-bidentate ligand [bis-(4-pyridyl)disulfide, bpds] or as an exo-tridentate connector [tris(3-pyridyl)benzene, tpyb]. The single crystal X-ray structures of [Cu2(mea)2(bpbenz)(NO3)](NO3)·2.75CH3OH (1), [Cu2(mea)2(bpbenz)2](CF3SO3)2·0.5(bpbenz)·3CH3OH (2), [Cu2(pa)2(bpac)2](ClO4)2 (3), [Cu2(mea)2(bpanth)](CF3SO3)2] (4), [Cu2(mea)2(CH3OH)(H2O)(bpanth)(NO3)2]·CH3OH·H2O (5), [Cu2(mea)2(bpanth)2](ClO4)2·2.5CH3OH (6), [Cu2(mea)2(bpds)2](CF3SO3)2·2CH3OH (7), [Cu2(pa)2(bpds)2](BF4)2 (8), [Cu2(mea)2(tpyb)(ONO2)](NO3)·CH3OH (9), and [Cu2(mea)2(tpyb)(FBF3)](BF4)·CH3OH (10) are reported. Compound 4 exhibits a linear chain structure, while compounds 1, 2, 3, 5, 6, 7, and 8 incorporate extended two-dimensional (2-D) grids. In compound 2 the 2-D networks are disposed parallel to each other, while in compounds 3 and 6 interlocked three-dimensional (3-D) structures resulting from inclined interpenetration of the 2-D sheets are observed. Compounds 7 and 8 consist of layers that pack to give channels running through the solid-state structure. In 9 and 10, the tris(3-pyridyl)benzene ligand interacts with the binuclear nodes to give channels. The role of hydrogen-bonding and stacking interactions in sustaining the supramolecular solid-state architectures in these materials is discussed.