586-91-4Relevant articles and documents
Photo-switchable smart metal-organic framework membranes with tunable and enhanced molecular sieving performance
Liu, Chuanyao,Jiang, Yunzhe,Zhou, Chen,Caro, Jürgen,Huang, Aisheng
, p. 24949 - 24955 (2018)
Developing a novel MOF membrane material with switchable separation performance is an exciting and challenging research project. In the present work, we report preparation of a new kind of light induced smart MOF membrane, i.e., Cu(AzDC)(4,4′-BPE)0.5 membrane, which shows (i) enhanced molecular sieving performance, and (ii) is able to respond quickly to external light stimuli. Two photo-switchable moieties are addressed in the Cu(AzDC)(4,4′-BPE)0.5 membrane: azobenzene and bis(4-pyridyl)ethylene. When the Cu(AzDC)(4,4′-BPE)0.5 membrane is in situ irradiated with Vis and UV light, the separation factor of a H2/CO2 mixture can be switched reversibly between 21.3 and 43.7. This switching effect is mainly caused by reduced CO2 adsorption in the UV-cis state as proven by independent adsorption studies. For a steric reason, adsorption of CO2 is limited for the UV-cis state. In full agreement with this model, the adsorption of other gases H2, CH4 and N2 as well as their permeation behaviour is not observably influenced by the trans-cis switching.
CH4 storage and CO2 capture in highly porous zirconium oxide based metal-organic frameworks
Yang, Qingyuan,Guillerm, Vincent,Ragon, Florence,Wiersum, Andrew D.,Llewellyn, Philip L.,Zhong, Chongli,Devic, Thomas,Serre, Christian,Maurin, Guillaume
, p. 9831 - 9833 (2012)
A series of porous Zr oxoclusters-based MOFs was computationally explored for their gas storage/capture performances. The highly porous UiO-67(Zr) and UiO-68(Zr) solids show exceptionally high CH4 and CO2 adsorption capacities under operating conditions that make these thermal, water and mechanical resistant materials very promising for physisorption-based processes. The Royal Society of Chemistry 2012.
Characterizing Defects in a UiO-AZB Metal-Organic Framework
Epley, Charity C.,Love, Madeline D.,Morris, Amanda J.
, p. 13777 - 13784 (2017)
Exploring defect sites in metal-organic framework materials has quickly become an interesting topic of discussion in the literature. With reports of the enhancement of material properties with increasing defect sites, we were interested in probing the defect nature of UiO-AZB (UiO = University of Oslo, AZB = 4,4′-azobenzenedicarboxylate) nanoparticles. In this report, we investigate the use of acetic, formic, and benzoic acids as the modulators to prepare UiO-AZB. The results of 1H NMR techniques and BET surface area analysis elucidate the extent of defects in our samples and are provided along with detailed discussions of the observed experimental trends. Interestingly, formic acid samples resulted in the most defected structure, reaching 36%. Additionally, for benzoic acid samples, with a 33% defect level, a drastic reduction in the accessible SA from 2682 m2/g to as low as 903 m2/g was observed, as the concentration of benzoic acid was increased. This was attributed to the creation of macropores in the individual crystallites and confirmed by average pore width analysis.
Efficient azobenzene co-sensitizer for wide spectral absorption of dye-sensitized solar cells
Zhang,Zou,Sun
, p. 6212 - 6217 (2018)
Two azobenzene dyes, [Cu(azobenzene-4,4′-dicarboxylate) diethylenediamine]n (ADD), [Cd(4,4′-diazenediyldibenzoato)(H2O)]n (DDB), have been designed, synthesized, and characterized as efficient co-sensitizers for dye-sensitized solar cells (DSSC). The optical, charge-transfer, electrochemical and photovoltaic properties of ADD and DDB are investigated by UV-visible spectroscopy, transient surface photovoltage measurement, cyclic voltammetry, and photocurrent-photovoltage measurement. The combination of ADD and DDB in DSSC leads to a wide spectral absorption over the whole visible range (350-700 nm). DSSC with ADD and DDB exhibits a short-circuit photocurrent density as high as 16.96 mA cm-2, open-circuit photovoltage of 0.73 V, a fill factor of 0.57, and overall light conversion efficiency of 7.1% under standard global AM1.5 solar irradiation conditions.
Ultrasound-assisted synthesis and characterization of a new metal-organic framework based on azobenzene-4,4-dicarboxylic acid: Precursor for the fabrication of Co3O4 nano-particles
Parsa, Fatemeh,Ghorbanloo, Massomeh,Masoomi, Mohammad Yaser,Morsali, Ali,Junk, Peter C.,Wang, Jun
, p. 197 - 203 (2018)
Azobenzene groups are widely known as photochromic ligands thus are particularly interesting building blocks for designing receptors for neutral or charged guests. A new metal-organic framework, [Co3(adc)3(DMF)4].2DMF (compound 1) (adc = azobenzene-4,4-dicarboxylic acid, DMF = N,N-dimethylformamide), was synthesized by solvothermal methods and structurally characterized using X-ray crystallography and a range of spectroscopic techniques. Also, nanorods of compound 1 have been synthesized by a sonochemical process and characterized by field emission scanning electron microscopy (FE-SEM) and powder X-ray diffraction (PXRD). The effect of sonication time and concentration of the initial reagents on the size and morphology of the MOF have been optimized. Results indicate that decreasing of initial concentration and increasing ultrasound radiation time lead to small size nanorods of compound 1. Thus, ultrasound radiation affects the size of nanorods. After heat treatment, the cobalt ion-based metal organic framework nanorods can be converted into porous Co3O4 nanoparticles.
Exposed Equatorial Positions of Metal Centers via Sequential Ligand Elimination and Installation in MOFs
Yuan, Shuai,Zhang, Peng,Zhang, Liangliang,Garcia-Esparza, Angel T.,Sokaras, Dimosthenis,Qin, Jun-Sheng,Feng, Liang,Day, Gregory S.,Chen, Wenmiao,Drake, Hannah F.,Elumalai, Palani,Madrahimov, Sherzod T.,Sun, Daofeng,Zhou, Hong-Cai
, p. 10814 - 10819 (2018)
Metal-organic frameworks (MOFs) provide highly designable platforms to construct complex coordination architectures for targeted applications. Herein, we demonstrate that trans-coordinated metal centers with exposed equatorial positions can be placed in a MOF matrix. A Zr-based MOF, namely, PCN-160, was initially synthesized as a scaffold structure. Postsynthetic linker labilization was subsequently implemented to partially remove the original dicarboxylate linkers and incorporate pyridinecarboxylates. A pair of neighboring pyridyl groups was arranged at proper proximity within the framework to form trans-binding sites that accommodate different metal cations including Mn2+, Fe2+, Co2+, Ni2+, Cu2+, and Pd2+. Furthermore, the trans-coordinated Ni2+ sites in porous frameworks can be readily accessed by substrates along the equatorial plane, facilitating the catalysis as manifested by the superior activity in ethylene dimerization over that observed for a cis-chelated catalyst.
Azo-Functionalized Zirconium-Based Metal?Organic Polyhedron as an Efficient Catalyst for CO2 Fixation with Epoxides
Ding, Shujiang,Fan, Hongbo,Tang, Jia,Wang, Xiaoxia,Wei, Fen,Xie, Guanqun
, p. 12890 - 12899 (2021/08/09)
Chemical fixation of CO2 as C1 source at ambient temperature and low pressure is an energy-saving way to make use of the green-house gas, but it still remains a challenge since efficient catalyst with high catalytic active sites is required. Here, a novel monoclinic azo-functionalized Zr-based metal?organic polyhedron (Zr-AZDA) has been prepared and applied in CO2 fixation with epoxides. The inherent azo groups not only endow Zr-AZDA with good solubilization, but also act as basic sites to enrich CO2 showing efficient synergistic catalysis as confirmed by TPD-CO2 analysis. XPS results demonstrate that the Zr active sites in Zr-AZDA possess suitable Lewis acidity, which satisfies both substrates activation and products desorption. DFT calculation indicates the energy barrier of the rate-determining step in CO2 cycloaddition could be reduced remarkably (by ca. 60.9 %) in the presence of Zr-AZDA, which may rationalize the mild and efficient reaction condition employed (80 °C and 1 atm of CO2). The work provides an effective multi-functional cooperative method for improvement of CO2 cycloaddition.
Unraveling the Self-Assembly of Heterocluster Janus Dumbbells into Hybrid Cubosomes with Internal Double-Diamond Structure
Liu, Hong-Kai,Ren, Li-Jun,Wu, Han,Ma, Yong-Li,Richter, Sven,Godehardt, Michael,Kübel, Christian,Wang, Wei
supporting information, p. 831 - 839 (2019/01/23)
Cubosomes are bicontinuous cubic-phase particles generated by amphiphile self-assembly with bicontinuous cubic phases, which creates an intricate network of interconnected nanochannels that endow these materials with special functions for advanced applications. On the other hand, clusters are an attractive class of molecules that exhibit intriguing functions and properties that differ from those of atoms and nanoparticles. Inspired by lipid self-assembly and attracted to the new functionalities of clusters, we prepared special heterocluster Janus dumbbells (HCJDs) composed of dissimilar nanoclusters: namely, a polyoxometalate and a polyhedral oligomeric silsesquioxane. HCJDs resemble conventional amphiphiles and, as such, they self-assemble in solution into faceted hybrid cubosomes via the transformation of vesicles into spongelike aggregates. Multiple mechanisms that lead to equilibrium, including molecular self-assembly, vesicle accumulation, membrane fusion, inner-structure reorganization, and cubic crystal growth, contributed to the overall process. On the basis of these results, we proposed a strategy for self-assembly - from basic molecular design that goes beyond traditional amphiphiles to the construction of micro- or nanomaterials with hierarchical structures and advanced functions.
