Hybrid Supramolecules for Azolium-Linked Cyclophane Immobilization and Conformation Study: Synthesis, Characterization, and Photocatalytic Degradation

3D Cyclophane for the Selective Conversion of Epoxide to Cyclic Carbonate

A novel three-dimensional (3D) cyclophane molecule 1 was synthesized and fully characterized. Cyclophane 1, which can form a N heterocyclic carbene, was tested for conversion of certain epoxides (3-6) [scheme 2] to cyclic carbonates in the presence of CO2. Propylene oxide (3) was found to have more reactivity with cyclophane 1 compared to the other epoxides. The theoretical calculations based on N,N'-disubstituted imidazol(in)ium-2-carboxylates derived from N,N' disubstituted imidazole as the source of N-heterocyclic carbene show lower activation energy in the case of the reactivity of epoxides 5 and 6 as compared to 3 and 4. However, cyclophane 1, which possesses a 3D geometry, can form the open intermediate with CO2 and propylene oxide more feasibly than the other three epoxides, which have larger sizes as compared to propylene oxide. Hence, the reaction of propylene oxide, CO2, and cyclophane 1 can follow the mechanistic path 1, whereas the epoxides 4-6 can follow a different mechanistic path 2. Cyclophane 1 is the first example of a cyclophane to act as an organocatalyst for the conversion of CO2 and epoxide to cyclic carbonate via the N heterocyclic carbene pathway.

Syntheses, structures, photoelectric properties and photocatalysis of iodobismuthate hybrids with lanthanide complex cations

New iodobismuthate hybrids with lanthanide complex counter cations, [Ln(DMF)₈][Bi₂I₉] (Ln = La (1), Eu (2)) and [Tb(DMF)₈]₂[Bi₂I₉]₂ (3) (DMF = N,N-dimethylformamide), were prepared using solvated Ln(III) complexes formed in situ as structure-directing agents. The dimeric [Bi₂I₉]^3- anion moieties of compounds 1-3 are aggregated by two slightly twisted BiI₆ octahedra through face-sharing mode. The different crystal structures of 1-3 are due to the different I⋯I and C-H⋯I hydrogen bond interactions. Compounds 1-3 have narrow semiconducting band gaps at 2.23, 1.91 and 1.94 eV, respectively. Under Xe light irradiation, they exhibit steady photocurrent densities that are 1.81, 2.10 and 2.18 times higher than that of pure BiI₃, respectively. Compounds 2 and 3 exhibited higher catalytic activities than 1 in the photodegradation of organic dyes CV and RhB, which are attributed to the stronger photocurrent response derived from the redox cycles of Eu³⁺/Eu²⁺ and Tb⁴⁺/Tb³⁺.

A Review of Crystalline Multibridged Cyclophane Cages: Synthesis, Their Conformational Behavior, and Properties

This paper reviews the most stable conformation of crystalline three-dimensional cyclophane (CP) achieved by self-assembling based on changing the type of aromatic compound or regulating the type and number of bridging groups. [3_n]cyclophanes (CPs) were reported to form supramolecular compounds with bind organic, inorganic anions, or neutral molecules selectively. [3_n]cyclophanes ([3_n]CPs) have stronger donor capability relative to compound [2_n]cyclophanes ([2_n]CPs), and it is expected to be a new type of electron donor for the progress of fresh electron conductive materials. The synthesis, conformational behavior, and properties of crystalline multi-bridge rings are summarized and discussed.

Preparation and application of one new supramolecular molybdenum oxygen cluster with adsorption of organic contaminants in wastewater

In this paper, one supermolecular compound, namely, p-[C20H18N2O4][Mo8O26]0.5·H2O (1) has been synthesized from 1,4-bis[4-nitrile-pyridine)-N-methylene]phenyldibromide (L1) and (NH4)6Mo7- O24·4H2O by hydrothermal method. The structure has been confirmed through single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra. The adsorption property of compound 1 has bee studied, Thus it’s much important to enrich the types of chemicals.

Preparation and application of two novel supramolecular polyoxmetalates with adsorption of organic contaminants in wastewater

Two new supramolecular polyoxmetalates were synthesized from 1, 4-bis[4-nitrile-pyridine)-N-methylene]phenyldibromide (L1) and 1, 2-bis[4-nitrile-pyridine)-N-methylene]phenyldibromide (L2) and (NH4)6Mo7–O24·4H2O under hydrothermal conditions. They are named p-[C20H18N2O4][Mo8O26] 0.5·H2O (1) and o-[C20H18N2O4][Mo8O26] ċ 0.5·H2O (2) respectively. The structures have been confirmed through single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra. The adsorption test of compound 1 and compound 2 in organic dyes were carried out. It was found that compound 1 had a good adsorption effect on methylene blue (MB) and rhodamine B (RhB). The adsorption effect of compound 2 on MB is stronger than that of compound 1.

Synthesis, structures and properties of Cd(II) supramolecular compound based on nitrogen heterocyclic cation

A novel supramolecular compound {(L1) [CdI4]} (L1 = 1-(3-(((1 s,3R,5S)-1,3,5,7,tetraazaadamantan-1-ium-1-yl)methyl)benzyl)-1,3,5,7,-tetraazaadamantan-1-ium) was synthesized from CdI2 and L1 by self-assembly reaction in solution. Its structure was analyzed by X-ray diffraction, and X-ray crystallography showed that the crystal was mononuclear. The compound was characterized by UV, TG, photocatalysis and adsorption.

Non-transient thermo-/photochromism of iodobismuthate hybrids directed by solvated metal cations

Two iodobismuthate-based organic-inorganic hybrids, [M(DMSO)₈][Bi₂I₉] (M = La (1), Bi (2)), have been successfully designed and synthesized by using solvated metal cations as structure-directing agents (SDAs). 1 displays transient high-temperature thermochromism, which is similar to that of the characteristic low-temperature thermochromic properties of bulk bismuth iodide and iodobismuthate hybrids. In contrast, 2 exhibits distinguishing non-transient thermochromic properties stimulated by the different temperature ranges of the thermal treatments. More importantly, a comparison of the optical inertness of 1 and 2 also reveals novel photochromic behavior. The completely different thermo-/photo-responsive properties of 1 and 2 are mainly ascribed to the different binding abilities of the central metal cations with DMSO molecules, which cause a distinct transformation of the inorganic moiety and consequent modulation of band gaps.

Preparation and Analyses of the Multifunctional Properties of 2D and 3D MOFs Constructed from Copper(I) Halides and Hexamethylenetetramine

In this article, two two-dimensional and three-dimensional metal-organic frameworks are synthesized by the self-assembly of copper(I) halide and the hexamethylenetetramine (hmt) ligand. Compound 1 is a two-dimensional metal-organic framework composed of a pyramidal Cu₄I₅ cluster and hexamethylenetetramine, in which hmt-bridged Cu clusters form a two-dimensional (4,4)-connected net with a point symbol of (4⁴·6²) (4⁴·6²). Compound 2 is a homochiral three-dimensional metal-organic framework material generated through an unusual spontaneous crystallization from achiral precursors. The two compounds were characterized by a series of analyses such as infrared spectroscopy, elemental analysis, circular dichroism spectroscopy, and powder X-ray diffraction. Both of them exhibit unexpected stability under a wide range of conditions of acid and base. In addition, the fluorescence intensity changes regularly under acid-base conditions. Stokes shift shows a good linear relationship with -log [H⁺], which makes them become promising acid-base sensors. Compounds 1 and 2 also display selective adsorption and a significant degradation effect on the organic dye methylene blue. In addition, the fluorescence study indicated that compound 2 could be used as a sensor to detect Cr³⁺.

Assembly and Adsorption Properties of Seven Supramolecular Compounds with Heteromacrocycle Imidazolium

Seven supramolecular compounds comprising multivalent imidazolium macrocycles and metal halides, {[MC-IM][Ag₂I₄]} _n (1), {[PC-IM]₂[Ag₇I₁₁]} _n (2), {[ODC-IM][Ag₃I₇]} (3), {[ODC-IM][Bi₂I₁₀]} (4), {[MDC-IM][Bi₂I₁₀]} (5), {[PDC-IM][Bi₂I₁₀]} (6), and {[MDC-IM][HgI₄]} (7), have been synthesized by solvothermal reactions and structurally characterized by IR spectroscopy, thermogravimetric analysis, and single-crystal X-ray diffraction. Notably, the three tetravalent imidazolium macrocycles were introduced for the first time and the extended anion structures are featured with three-dimensional coordination networks, one-dimensional chains, or zero-dimensional oligomers. This new study attempts to not only fill the gap in this supramolecular hybrid area that has been neglected but also enrich the type of imidazolium cyclophane. It is important that good efforts were devoted to study the adsorption properties of supramolecular compounds. Compound 5 exhibited great adsorption performance for organic dyes methylene blue, methyl orange, and rhodamine B (RhB) and can be evaluated as a potential candidate for industrial wastewater treatment.