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

Abstract

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.