•A novel imidazole-phosphonic acid was firstly used to synthesize MOFs.•The synthesized MOF has remarkable thermal and chemical stabilities.•The synthesized MOF showed high selectivity and sensitivity for sensing Cu2 + ions.A phosphonic acid, 4-(1H-imidazole-4-yl)phenylphosphonic acid (H3piz) was firstly synthesized and used as a ligand to construct a metal phosphonate, [(ZnHpiz)]n (ZnPIF-1). The structure of ZnPIF-1 features as “inorganic” zinc phosphate chains, which are linked with the neighboring ones by Hpiz2 − into a two-dimensional (2-D) layered structure. Study of thermal and chemical stability of ZnPIF-1 demonstrated its high thermal stability and remarkable chemical resistance to boiling water and acid/alkaline condition. Furthermore, luminescence studies revealed that ZnPIF-1 showed high selectivity and sensitivity for sensing Cu2 + ions over other metal ions.A phosphonic acid, 4-(1H-imidazole-4-yl)phenylphosphonic acid (H3piz) was firstly synthesized and used as a ligand to construct a metal phosphonate, [(ZnHpiz)]n (ZnPIF-1), which shows high selectivity and sensitivity for sensing Cu2 + ions over other metal ions.Download high-res image (392KB)Download full-size image

The chemisorption of gaseous HCl molecules in a two-dimensional coordination polymer results in subtle changes in its structure and instigates a drastic modification from antiferro- to ferromagnetic properties.

Butylated pillar[5]arene (1) and N,N′-bis(n-butyl)pyromellitic diimide (2) form a 2:1 sandwich-type complex external to the walls of the receptor (“exo-wall” complex). The marriage of exo-wall interactions and endo-cavity inclusion provides a new strategy for the construction of supramolecular polymers from unfunctionalized neutral receptors.

An indium phosphonocarboxylate framework, {H3O[In(pbpdc)]·3H2O}n (InPCF-1) (pbpdc = 4′-phosphonobiphenyl-3,5-dicarboxylate), was hydrothermally synthesized. The structure of InPCF-1 features the inorganic chains as rod-shaped second building units. The rod-packing arrangement results in a three-dimensional (3-D) framework with a novel (3,4,5)-connected net. Studies of the gas adsorption, and thermal and chemical stability of InPCF-1 demonstrated its adsorption capacity for CO2, selective separation of CO2 over O2 and N2, high thermal stability, and a remarkable chemical resistance to boiling water, ethyl alcohol, and methylbenzene. Importantly, InPCF-1 shows a selective and sensitive response to Cu2+ ions. It also serves as a sensor for methylviologen.

3-Phosphonobenzoic acid (3-H3pbc) was designed as an extended 4-connected ligand to build zeolite-like metal–organic frameworks (ZMOFs). Controlled assembly of Zn2+ with ligand 3-H3pbc results in two distinct structures with zeolitic topologies of MER and RHO, namely [Zn(3-pbc)]·H3O·0.5H2O (1) and Zn2.5(3-pbc)2(H2O)·nS (S represents the disordered solvent molecules) (2), respectively. The framework of 1 consists of double crankshaft chains formed by alternating ZnO4 and O3PC tetrahedra that are cross-linked by 3-pbc to generate a three-dimensional zeolitic open-framework. It is worth noting that structure 2 builds a zeolitic framework in a novel way, which has not been found in other metal phosphonocarboxylates. The organic part of 3-pbc does not participate in the construction of zeolitic topology and only plays a decorative role inside the cages.

A 2D phosphonate MOF {[Ni(Hptz)2]·7H2O}n (H2ptz = 4-(1,2,4-triazol-4-yl)phenylphosphonic acid) (2) is obtained through crystal transformation from a trinuclear compound [Ni3(Hptz)6·(H2O)6]·9H2O (1). Studies of chemical stability show that 2 retains its crystallinity in boiling water and organic solvents. 2 also exhibits high adsorption capacity for CO2 (80 cm3(STP) g−1) and selective separation of CO2 over N2.

Highlights•Novel 4-(1,2,4-triazol-4-yl)phenylphosphonic acid (H2ptz) as ligand.•X-ray crystallographic analyze of two isostructural metal phosphonates.•Antiferromagnetic interactions between oxo- and diazo-bridged metal centers.A phosphonic acid, 4-(1,2,4-triazol-4-yl)phenylphosphonic acid (H2ptz) was used as a new ligand to construct magnetic materials, by which two 2-dimensional (2D) layered metal phosphonates, [M5(Hptz)2(ptz)4]n (where M = Co(II) (1) and Mn(II) (2)) have been hydrothermally synthesized. Both compounds were characterized by elemental analyses, infrared spectroscopy, powder X-ray diffraction and X-ray single-crystal diffraction. Structure analyses reveal that 1 and 2 are isostructures, where the metal and ptz ligands form M5(Hptz)2(ptz)4 subunits, which are further linked together into a 2-D layered structure. The magnetism studies over the temperature range 2–300 K showed pronounced antiferromagnetic interactions between the combined oxo- and diazo-bridged metal centers in both 1 and 2.Graphical abstractTwo isostructural 2-dimensional (2D) layered metal phosphonates, [M5(Hptz)2(ptz)4]n (where M = Co(II) (1) and Mn(II) (2)) have been hydrothermally synthesized by using 4-(1,2,4-triazol-4-yl)phenylphosphonic acid (H2ptz) as a novel ligand. The magnetism studies over the temperature range 2–300 K showed pronounced antiferromagnetic interactions between the combined oxo- and diazo-bridged metal centers in both 1 and 2.

Highly effective binding of neutral dinitriles by simple alkyl-substituted pillar[5]arenes and the formation of interpenetrated geometries are reported. The resulting host–guest complexes represent one of the most efficient recognition motifs based on pillararenes.

The selective and effective binding of secondary ammoniums with a weakly coordinating tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BArF) counteranion by per-ethylated pillar[5,6]arenes is reported. The construction of a first pillararene-based self-sorting system consisting of two wheels and two axles is also described.

Organic nanotubes have been assembled from pillar[5]arenes 1 and 2. Compound 1 gelates organic solvents through the formation of tubular fibers which are evidenced by TEM and XRD experiments, while 2 assembles into two different channels under the template effect of water wires. In addition, the water wires in the nanotubes of 2 can be under selective proton conductance. The results described herein represent a new strategy for building tubular structures.

An indium phosphonocarboxylate framework, {H3O[In(pbpdc)]·3H2O}n (InPCF-1) (pbpdc = 4′-phosphonobiphenyl-3,5-dicarboxylate), was hydrothermally synthesized. The structure of InPCF-1 features the inorganic chains as rod-shaped second building units. The rod-packing arrangement results in a three-dimensional (3-D) framework with a novel (3,4,5)-connected net. Studies of the gas adsorption, and thermal and chemical stability of InPCF-1 demonstrated its adsorption capacity for CO2, selective separation of CO2 over O2 and N2, high thermal stability, and a remarkable chemical resistance to boiling water, ethyl alcohol, and methylbenzene. Importantly, InPCF-1 shows a selective and sensitive response to Cu2+ ions. It also serves as a sensor for methylviologen.

Butylated pillar[5]arene (1) and N,N′-bis(n-butyl)pyromellitic diimide (2) form a 2:1 sandwich-type complex external to the walls of the receptor (“exo-wall” complex). The marriage of exo-wall interactions and endo-cavity inclusion provides a new strategy for the construction of supramolecular polymers from unfunctionalized neutral receptors.

Highly effective binding of neutral dinitriles by simple alkyl-substituted pillar[5]arenes and the formation of interpenetrated geometries are reported. The resulting host–guest complexes represent one of the most efficient recognition motifs based on pillararenes.

The chemisorption of gaseous HCl molecules in a two-dimensional coordination polymer results in subtle changes in its structure and instigates a drastic modification from antiferro- to ferromagnetic properties.