Structural diversity and modulation of metal-organic coordination frameworks with a flexible V-shaped dicarboxyl building block

A family of new coordination polymers based on a V-shaped flexible dicarboxyl building block 4,4′-(hexafluoroisopropylidene)bis(benzoic acid) and familiar metal ions (Mn^II, Co^II, Ni^II, Cu^II, Zn^II, and Ag^I) have been prepared and structurally characterized. Their thermal stability and solid state luminescent properties of the Zn^II and Ag^I complexes have also been investigated. Single-crystal X-ray diffraction analysis reveals a significant structural diversity of these coordination frameworks, such as the 1-D zigzag chain, 2-fold interpenetrating layer composed of 2₁ helical arrays, and 3-D open network with 4₂ helicity and pcu topology based on the rod-shaped secondary building units (SBUs). Additionally, hydrogen bonding interactions are found in these structures to further extend or stabilize the coordination motifs. A comprehensive analysis of the coordination systems based on this dicarboxyl tecton also demonstrates that it is an excellent candidate for the design and construction of multiform metal-organic frameworks (especially helical arrays), which can be dominated by metal ions and/or synthetic conditions.