Weicong Liu

Luminescent sensing from a new Zn(II) metal–organic framework

A new metal–organic framework having the formula (NH2(CH3)2)[Zn2(OAc)(L)]·0.5DMF (H4L = 2,5-di(3′,5′-dicarboxylphenyl)pyridine) (GDMU-3) has been synthesized and characterized. The net of GDMU-3 is uninodal and is closely related to the lvt net, which has the same Schlafli symbol of 42·84. GDMU-3 displays selective properties for the detection of nitrobenzene and Fe3+ ions. Remarkably, GDMU-3 exhibits an excellent capability to adsorb methylene blue with high selectivity. The present work indicates that GDMU-3 could be a potential candidate for developing novel luminescence sensors for the selective sensing of nitrobenzene which can be deployed for explosives, Fe3+ and organic dyes.

Rational synthesis of a novel 3,3,5-c polyhedral metal–organic framework with high thermal stability and hydrogen storage capability

By using a functionalized ligand strategy, a novel (3,3,5)-c polyhedron-based metal–organic framework (GDMU-2) with high thermal stability has been constructed. GDMU-2 shows a high H2 uptake of 240.7 cm3 g−1 (2.16 wt%) at 77 K and 1 bar, and also exhibits a good selective adsorption of CO2 over N2 and CH4.

A new Zn(II) metal–organic framework having 3D CdSO4 topology as luminescent sensor and photocatalyst for degradation of organic dyes

A new Zn(II) metal–organic framework, formulated as {[Zn(L)]·2.7 DMF} (1), was synthesized using a multidentate ligand 1,4-bis(triazol-1-yl)terephthalic acid (H2L). The MOF 1 adopts 3D uninodal 4-c CdSO4 topology and behaves as a luminescent chemosensor for highly selective and sensitive detection of Fe3+ and nitro-aromatics, particularly 2,4,6-trinitrophenol (TNP). In addition, the thermal stability, UV/Vis diffuse-reflection spectra and photocatalytic behaviors of 1 against organic dyes have also been investigated. The possible mechanism associated with the alleviation in the emission intensity of 1 in the presence of nitro-aromatic compounds were addressed by theoretical calculations. In addition, the photocatalytic activity of 1 against organic dyes was addressed using density of states (DOS) calculations.

A 2D Cd(II)-MOF as a multifunctional luminescencent sensor for nitroaromatics, iron(III) and chromate ions

Abstract A Cd(II)-MOF, {[Cd(L)(4,4′-bipy)]·H2O·DMF}n (1) (L = nicotinic acid (2,4-dihydroxybenzylidene)-hydrazide and 4,4′-bipy = 4,4′-bipyridine), has been synthesized and characterized by microanalyses, FTIR, TGA, and single-crystal X-ray diffraction. Additionally, powder X-ray diffraction was performed to check the phase purity of the synthesized compound. Single-crystal X-ray diffraction reveals that 1 has a 2D grid network. Photoluminescent sensing of nitrobenzene, Fe(III) and CrO42− ions indicates that 1 could be a candidate for developing selective luminescent sensors for these species. Theoretical calculations have been performed to gain insight into the possible mechanism of quenching effect in emission on addition of nitrobenzene in 1 which supports the mechanism operating through ground state charge transfer between 1 and nitrobenzene.

Selective adsorption and removal of drug contaminants by using an extremely stable Cu(II)-based 3D metal-organic framework

The adsorption capacity of three representative pharmaceutical drugs and personal care products (PPCPs) viz. diclofenac sodium (DCF), chlorpromazine hydrochloride (CLF) and amodiaquin dihydrochloride (ADQ), were preliminarily studied using a water-stable Cu(II)-based metal organic framework (MOF) [Cu(BTTA)]n·2DMF (1) (H2BTTA = 1,4-bis(triazol-1-yl)terephthalic acid). We also investigated the factors influencing the adsorption such as concentration, pH, contact time, temperature and dosages. The results show that the adsorption capacity of 1 for DCF (650 mg g-1) from aqueous medium, which is higher in comparison to most of the reported MOFs. While the adsorption of CLF and ADQ are only 67 mg g-1 and 72 mg g-1, respectively. The adsorption isotherm and adsorption kinetics indicated that the adsorption of diclofenac sodium by 1 follows Freundlich model with R2 value of 0.9902 and pseudo-first-order kinetics with correlation coefficient 0.9939 and K1 value of 0.0058 min-1, respectively. Investigations indicate that 1 could become a potential material to adsorb DCF from aqueous medium.

A 3D Stable Metal–Organic Framework for Highly Efficient Adsorption and Removal of Drug Contaminants from Water

We herein selected a 3D metal–organic framework decorated with carboxylate groups as an adsorbent to remove the pharmaceutical molecules of diclofenac sodium and chlorpromazine hydrochloride from water. The experiment aimed at exploring the effect factors of initial concentration, equilibrium time, temperature, pH and adsorbent dosage on the adsorption process. The adsorption uptake rate of the diclofenac sodium is much higher than that of the chlorpromazine hydrochloride. This paper presents the high adsorption capacity of diclofenac sodium, in which porous MOFs are used for the removal of drug contaminants from water. According to linear fitting with adsorption isotherm equation and kinetic equations, diclofenac sodium conforms to the Langmuir model and pseudo-first-order kinetic equation, while chlorpromazine hydrochloride accords with the Temkin model and pseudo-second-order kinetic equation. The results of the study indicate that the title compound could be a promising hybrid material for removing diclofenac sodium and chlorpromazine hydrochloride from wastewater.

Metal–Organic Framework (MOF)-based Nanomaterials for Biomedical Applications

Metal-organic frameworks (MOFs) are compounds consisting of metal ions or clusters coordinated to organic ligands to form one-, two-, or three-dimensional structures. They are a subclass of coordination polymers (CPs), with the special feature that they are often porous. The organic ligands are sometimes referred to as second building structs. The new porous materials have paid great attention because of the variety of advantages such as tunable components, structural diversity, high loading performance and favorable biodegradability. In this review, we highlighted the recent progress on the drug delivery application of MOFs, especially emphasizing the application of pH-responsive delivery as well as magnetic-guided drug delivery systems (DDSs). Subsequently, the applications of MOFs in magnetic resonance imaging (MRI), optical imaging (OI), X-ray computed tomography (CT) imaging and multimodality imaging will be discussed. Finally, we will provide an overview for the photodynamic therapy and the toxicity feature of MOFs.

A new metal-organic framework constructed from tetracarboxylate: Structure, magnetism and simulation

ABSTRACT A new metal-organic framework of [Cu2(L)(H2O)2]·2DMF (1) (H4L = quaterphenyl-3,3′″,5,5′″-tetracarboxylic acid) has been prepared and characterized. It has the NbO-derived topology that was observed in MOF-505. Magnetic study reveals the overall antiferromagnetic interactions between neighboring Cu(II) ions in compound 1. In addition, we performed an optimization by semiempirical PM5 method simulations to investigate the loading of 5-FU to 1 at the molecular level.