Assembly of Metal-Organic Frameworks with Helical Layer: From 2D Parallel Interpenetrated Layer to 3D Self-Penetrating Network

Two novel Co(II)-organic frameworks with helical structures, [Co(hfipbb)(py)](n) (1) and {[Co-4(OH)(H2O)(hfipbb)(3)-(Hhfipbb)(bpp)(2)]center dot H2O}(n) (2) (H(2)hfipbb = 4,4'-(hexafluoroisopropylidene)bis(benzoic acid), py = pyridine, bpp = 1,3-bis(4-pyridyl)propane), have been assembled from flexible bent ligands. Complex 1 displays a 2-fold parallel interpenetrated layer network with one-dimensional double helical channels, while 2 exhibits a three-dimensional pillared helical-layer open framework with six-connected self-penetrating topology based on a mixed dinuclear paddle-wheel cluster and tetranuclear [Co-4(mu(3)-OH)(2)(mu(2)-OH2)(2)] steplike cluster.