Reaction of copper(ii) tetrazolate-5-carboxylate with different neutral N-donor spacer ligands under hydrothermal conditions leads to the formation of five new coordination polymers,[Cu(tzc)(pyz)(0.5)(H(2)O)(2)](n)·H(2)O (1),[Cu(tzc)(pyz)](n)(2),[Cu(tzc)(pym)(H(2)O)](n)(3),[Cu(tzc)(dpe)(0.5)(H(2)O)](n)(4) and [Cu(tzc)(azpy)(0.5)(H(2)O)](n)(5)(tzc = tetrazolate-5-carboxylate, pyz = pyrazine, pym = pyrimidine, dpe = 1,2-di(4-pyridyl)ethylene and azpy = 4,4'-azopyridine). All five structures were characterized by X-ray single-crystal measurements and bulk material can be prepared phase pure in high yields. The crystal structures of the hydrates 1, 3, 4 and 5 show dimeric [Cu(2)(N(tzc)-N(tzc))(2)] building units formed by μ(2)-N1,O1:N2 bridging tzc ligands as the characteristic structural motif. These six-membered entities in 1, 4 and 5 are connected by μ(2)-N,N' bridging N-donor ligands into 1D chains and in 3 into 2D layers. In the crystal structure of compound 2 adjacent Cu(ii) cations are connected by μ(2)-N1,O1:N4,O2 bridging tzc ligands into chains, which are further connected by μ(2)-N,N' bridging pyz ligands forming 2D layers. Extensive hydrogen bonds in all compounds play an important role in the construction of their supramolecular networks. Investigations of their thermal properties reveal water release upon heating according to the formation of anhydrates before starting decomposing above 220 °C. Furthermore, the magnetic properties have been studied leading to consistent global antiferromagnetic exchange interactions with coupling constants of J = 3 ± 1 cm(-1) and long-range antiferromagnetic ordering states at lower temperatures.

Despite great efforts, the development of a reliable way to assemble mesoporous metal-organic frameworks (mesoMOFs) remains a challenge. In this work, we have designed a cooperative template system, comprising a surfactant (cetyltrimethylammonium bromide) and a chelating agent (citric acid), for the generation of a mesoMOF containing a hierarchical system of mesopores interconnected with microspores. The surfactant molecules form micelles and the chelating agent bridges the MOF and the micelles, making self-assembly and crystal growth proceed under the direction of the cooperative template. However, when the surfactant or the chelating agent was applied individually, no mesoMOF was obtained.

A metal-organic framework (MOF) for reversible alteration of guest molecule adsorption, here carbon dioxide, upon photochemical or thermal treatment has been discovered. An azobenzene functional group, which can switch its conformation upon light irradiation or heat treatment, has been introduced to the organic linker of a MOF. The resulting MOF adsorbs different amount of CO2 after UV or heat treatment. This remarkable stimuli-responsive adsorption effect has been demonstrated through experiments.

Porous polymer networks (PPNs) grafted with sulfonic acid (PPN-6-SO3H) and its lithium salt (PPN-6-SO3Li) exhibit significant increases in isosteric heats of adsorption for CO2 and CO2-uptake capacities. At 295 K and 1 bar, IAST calculations, using the single-component-isotherm data and a 15/85 CO2/N2 ratio, reveal that sulfonate-grafted PPN-6 show exceptionally high adsorption selectivity for CO2 over N2 (155 and 414 for PPN-6-SO3H and PPN-6-SO3Li, respectively). Given that these PPNs also possess ultra-high physicochemical stability, practical applications in the post-combustion capture of CO2 lie well within the realm of possibility.