A novel isohedral 3-periodic net (i.e. a net with one kind of tile), showing a Cairo pentagonal tiling projection on the Euclidean plane, has been identified in a series of site-modified CuCN/CuSCN networks, namely, [Cu₆(SCN)₂(CN)₆⋅Ni(tpy)₂]_n (1), [Cu₆(SCN)(CN)₇⋅Ni(tpy)₂]_n (2) and [Cu₆(CN)₈⋅Ni(tpy)₂]_n (3) (tpy=2,2′:6′′,2′′-terpyridine). These infinite inclusion compounds were prepared via a solvothermal sulfur migration reaction with subtle modification to fine-tune the sulfur content. The chiroptical activity of single crystals, which arises from the intrinsically chiral net, was confirmed by X-ray diffraction and solid-state circular dichroism spectra.

Biological and artificial molecules and assemblies capable of supramolecular recognition, especially those with nucleobase pairing, usually rely on autonomous or collective binding to function. Advanced site-specific recognition takes advantage of cooperative spatial effects, as in local folding in protein–DNA binding. Herein, we report a new nucleobase-tagged metal–organic framework (MOF), namely ZnBTCA (BTC=benzene-1,3,5-tricarboxyl, A=adenine), in which the exposed Watson–Crick faces of adenine residues are immobilized periodically on the interior crystalline surface. Systematic control experiments demonstrated the cooperation of the open Watson–Crick sites and spatial effects within the nanopores, and thermodynamic and kinetic studies revealed a hysteretic host–guest interaction attributed to mild chemisorption. We further exploited this behavior for adenine–thymine binding within the constrained pores, and a globally adaptive response of the MOF host was observed.

Biological and artificial molecules and assemblies capable of supramolecular recognition, especially those with nucleobase pairing, usually rely on autonomous or collective binding to function. Advanced site-specific recognition takes advantage of cooperative spatial effects, as in local folding in protein–DNA binding. Herein, we report a new nucleobase-tagged metal–organic framework (MOF), namely ZnBTCA (BTC=benzene-1,3,5-tricarboxyl, A=adenine), in which the exposed Watson–Crick faces of adenine residues are immobilized periodically on the interior crystalline surface. Systematic control experiments demonstrated the cooperation of the open Watson–Crick sites and spatial effects within the nanopores, and thermodynamic and kinetic studies revealed a hysteretic host–guest interaction attributed to mild chemisorption. We further exploited this behavior for adenine–thymine binding within the constrained pores, and a globally adaptive response of the MOF host was observed.

Three 2D luminescent isomeric porous coordination polymers are synthesized and characterized. Their luminescence properties can be modified by grinding and they can act as mechanochromic materials and their properties are probably related to the weak interactions of cuprophilicity and π–π interactions.

A novel hydrophobic metal–organic framework (MOF), namely Cu₂L (L=3,3′,5,5′-tetraethyl-4,4′-bipyrazolate), is synthesized through a stepwise method, and exhibits an unprecedented 3,4-c net. The exceptionally thermal, chemical, and air stability of this MOF, especially in water and under acidic or basic conditions, and its selective and fast sorption capacity for hydrocarbons over water warrant its direct use for efficient removal of trace organic wastes (e.g. benzene, toluene, xylene, and mixtures thereof) from contaminated water.

Two classical copper(I)-cluster-based luminophores, namely, Cu₄I₄ and [Cu₃Pz₃]₂ (Pz=pyrazolate), are immobilized in a supramolecular system through the formation of metal–organic framework (MOF) materials. This series of luminescent MOF materials, namely, [Cu₄I₄(NH₃)Cu₃(L1)₃]_n, [Cu₄I₄(NH₂CH₃)Cu₃(L1)₃]_n, and [Cu₄I₄Cu₃(L2)₃]_n (L1=3-(4-pyridyl)-5-(p-tolyl)pyrazolate; L2=3-(4-pyridyl)-5-(2,4-dimethylphenyl)pyrazolate), exhibit diverse thermochromism attributed to the relative functioning efficacy of the two coordination luminophores. Such an intriguing chemopalette effect is regulated by the different supramolecular microenvironments between the two-dimensional layers of these MOFs, and in particular, by the fine-tuned Cu–Cu distances in the excimeric [Cu₃Pz₃]₂ luminophore. The structure–property elucidation of the thermochromic behavior allows one to understand these optical materials with unusual dual-emissive properties.

Solvothermal reactions of Cu^II salts and 3,5-bis(4-pyridyl)pyrazole (HL) under various conditions gave three different types of crystalline compound, namely [Cu₂(Cu₅L₆)]BF₄⋅5 H₂O (1 a), [Cu₂(Cu₅L₆)]ClO₄⋅5 H₂O (1 b), and [Cu₇(CN)₂(Cu₅L₆)₂][BF₄]₃ (2). 1 a and b were obtained in ethanol and NH₃⋅H₂O, whereas 2 was obtained in methanol and NH₃⋅H₂O. The three complexes were constructed by incorporating new pentanuclear copper(I) pyrazolate bis(triple helical) cluster helicates (Cu₅L₆) as the second building units (SBUs), in which as many as twelve 4-pyridyl N atoms are available for further coordination and construction of high-connectivity topological networks. In 1 a and b, seven 4-pyridyl N atoms are linked to three three-coordinated Cu^I atoms and four four-coordinated Cu^I atoms, which results in 3,4,7-connected networks. In 2, as many as eleven 4-pyridyl N atoms coordinate to eleven Cu^I atoms, which results in a 4,10-connected topological network. The increasing connectivity of the cluster nodes in 2 is closely related to the in situ-formed CN⁻ anion bridge around the periphery of the pentanuclear cluster helicates. The luminescenct properties of these compounds were also investigated.