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

Two novel lead(II) complexes of 2-(hydroxymethyl)pyridine: a threefold diamondoid supramolecular network based on Pb4O4cores and a two-dimensional (4,4) network based on Pb2O2units

“…In recent years, much attention has been focused on the construction of metal-organic assemblies in coordination chemistry and crystal engineering, stemming from their intriguing structural motifs and their potential uses in a variety of applications (Cui et al, 2012;Li, Sculley & Zhou, 2012;Suh et al, 2012;Sumida et al, 2012). The synthesis of these species is often based on the self-assembly of suitable building blocks to give supramolecular networks through metal-ligand coordination bonding and various kinds of weak intermolecular interactions, such as hydrogen bonds,stacking and weak C-HÁ Á ÁX (X = O, N and ) interactions (Jiang et al, 2009;Ling et are largely dependent on the coordination preference of the metal cation, the coordinative sites and their geometry, and any potential weak interaction sites in the ligands. From a synthetic point of view, transition metal cations are more natural choices, owing to their well defined coordination geometries.…”

A novel (4,6)-connected double-layered BaIIcoordination polymer based on the flexible tricarboxylate ligand 2,2′,2′′-[1,3,5-triazine-2,4,6-triyltris(sulfanediyl)]triacetic acid

“…The latter, however, can adopt variable conformations according to the geometric requirements of different metal ions, and may afford unpredictable and interesting architectures (Gomez-Lor et al, 2005;Zang et al, 2006;Dong et al, 2007). To the best of our knowledge, only limited work has been carried out using polycarboxylate ligands with characteristics of both flexibility and rigidity (Jiang et al, 2009;Harbuzaru et al, 2008;Cen et al, 2009). Likewise, in contrast with the well investigated transition and lanthanide metal systems, only a few alkaline earth coordination polymers have been studied.…”

pH- and metal-dependent structural diversity from mononuclear to two-dimensional polymers based on a flexible tricarboxylate ligand

“…Flexible ones, however, can adopt different conformations to decrease the geometric constrain and steric hindrance, so may form unpredictable intriguing topologies and properties. In addition, various kinds of intermolecular weak interactions, such as O-H?O (N) hydrogen bonds, weak C-H?X (X¼O, N, p) and p?p stacking interactions, are always observed [28][29][30][31][32][33][34][35][36]. They can cooperate with metal-ligand coordination bonding, leading to interesting supramolecular architectures.…”