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abstracts
Three regioisomers (o-L, m-L, and p-L) of bis(cyanobenzyl)sulfide were employed to examine the effect of ligand isomers on the networking assembly. In the reaction of m-L with silver(I) nitrate, supramolecular isomers 1 and 2 of stoichiometry [Ag2(m-L)(NO3)2]n, each comprising a 2D polymeric network were obtained on varying the mole-ratio of the reactant (see the below scheme). Notably, the overall structural motifs of 1 and 2 are mainly due to the conformational differences of the tridentate m-L: `S-shaped' in isomer 1 and `V-shaped' in isomer 2. Under identical reaction conditions, the ligand isomers o-L and p-L yield a loop-chain type 1D coordination polymer [Ag(o-L)NO3]n (3) and a multichannel 3D framework structure [Ag2(p-L)(NO3)2]n (4), respectively. The formation of these products shows no mole-ratio dependency.1 Among the ligand isomer, p-L showed the anion-dependent complexes 5-7 with different topologies in the reactions of silver(I) salts (X = ClO4-, PF6-, or CF3CO2-). AgClO4 afforded a double-stranded 1D polymer of type [Ag(p-L)(ClO4)]n (5). Meanwhile, treatment of AgPF6 and AgCF3CO2 afforded a 2-fold interpenetrated 3D coordination polymer {[Ag3(p-L)4](PF6)3·4CH2Cl2}n (6) and a multichannel 3D network [Ag2(p-L)(CF3CO3)2]n (7), respectively.
abstracts
Our interest in the development of MOFs with the cavities controlled by guest species has led us to investigate the MOFs based on calix[4]arene derivatives, in which metal ions link the calix unit to give the networks with the cavities accommodating several guest species, because the calix[4]arene-based MOFs contain porosity associated with both the ligand itself and the structural framework. In the present work, we employed a low rim-functionalized calix[4]arene tetraacetic acid (H4CTA) with 1,3-alternative conformation as a multidentate building block and alkyldiamines as the guest molecules. In the solvothermal reaction of H4CTA and Zn(II) ion in the presence of alkyldiamines, two types of new MOFs based on calix[4]arene tetraacetate (CTA4-) depending on the lengths of α,ω–alkyldiammonium guests have been synthesized by including suitable alkyldiammonium guests. Their single-crystal X-ray diffraction analyses reveal that the short alkyldiammonium guests such as ethyldiammonium, propyldiammonium, and butyldiammonium lead to form two-dimensional framework with the cavity consisting of two CTA4- and four Zn(II) ions whereas the alkyldiammonium guests such as heptyldiammonium, octyldiammonium, nonyldiammonium, and decyldiammonium give rise to generate three-dimensional network with the cavity surrounded by six CTA4- and four Zn(II) ions. The alkyldiammonium guests in both MOFs are well accommodated by each cavity via a variety of supramolecular interactions including electrostatic interactions, hydrogen bonds and van der Waals interactions. We will present and discuss a study on the syntheses and characterization of two new MOFs based on calix[4]arene derivative.
