Ni-doped MOF-5s were successfully synthesized for the first time via solvothermal crystallization process to enhance the hydrostability. Several characterization techniques, including X-ray diffraction (XRD), thermogravimetrical analysis (TGA), scanning electron microscopy (SEM), energy-dispersive spectroscopy instrument (EDS), inductively coupled plasma (ICP), infrared spectroscopy (IR), atomic sorption, diffuse-reflectance UV-vis spectroscopy, and gas sorption measurement, strongly support the effective incorporation of Ni(II) ions into the framework. The results demonstrated that the Ni-doped MOF-5s not only exhibit larger Langmuir specific surface areas and larger pores than the undoped MOF-5, but also significantly enhance water resistance of the framework. The H(2) uptake capacity of undoped MOF-5 drops rapidly when exposed to the ambient air, whereas the H(2) adsorptions of the Ni-doped MOF-5s remain stable for 4 days.
Two new 3D lanthanide(III)-copper(II) organic frameworks based on unusual {OLn6} clusters have been successfully synthesized and fully characterized. Crystallographic studies showed that the {OLn6} clusters acted as 12-connected nodes that were linked together by [CuL2] (H2L = 3-hydroxypyrazine-2-carboxylic acid) moieties to construct an interesting 4,12-c net with the point symbol {4(36).6(30)}{4(4).6(2)}3. Magnetic studies revealed that these two isostructural heterometallic frameworks exhibited different magnetic properties, depending on the different anisotropies of the lanthanide spin carriers: Gd-Cu showed a large magnetocaloric effect, with an entropy change (-ΔS(m)) of 35.76 J kg(-1) K(-1), which is one of the largest values in high-dimensional complexes, whilst Dy-Cu exhibited slow relaxation of the magnetization at low temperatures.
NiO nanoparticles were in situ formed in a new metal-organic framework (MOF), [Ni(pyip)(HCOO)(HO)] [1; Hpyip = 5-(pyridine-4-yl)isophthalic acid], which was characterized by Fourier transform infrared spectroscopy, elemental analysis, thermogravimetric analysis, transmission electron microscopy, and powder and single-crystal X-ray diffraction. The MOF 1 shows a 3,6-connected three-dimensional rtl topology network with a topological symbol of (4.6)(4.6.8). Magnetic property studies showed that the combination of NiO nanoparticles within the magnetic MOF leads to the occurrence of long-range magnetic ordering below a critical temperature of 18 K.
A framework approach was successfully performed to give a three-dimensional heterometallic compound exhibiting single-ion magnet (SIM) behavior. Enhanced SIM behavior was obtained by continuous application of diamagnetic-ion dilution and an external dc field.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.