Metathesis in Single Crystal: Complete and Reversible Exchange of Metal Ions Constituting the Frameworks of Metal−Organic Frameworks

Metathesis in Single Crystal: Complete and Reversible Exchange of Metal Ions Constituting the Frameworks of Metal−Organic Framework

Metathesis in Single Crystal: Complete and Reversible Exchange of Metal Ions Constituting the Frameworks of Metal−Organic Frameworks

Metathesis in Single Crystal: Complete and Reversible Exchange of Metal Ions Constituting the Frameworks of Metal−Organic Framework

Gravity model OLS regression results.

Gravity model OLS regression results.</p

Hierarchical tree of 41 topics detected from the dynamic topic model.

Topics were agglomerated by the ward.D method [50]. The distance between topics was measured by the Jensen-Shannon distance [51], a square root of the Jensen-Shannon divergence. Five topical clusters—material, plasma, device, diagnostics, and simulation—are revealed. The branches are colored by the corresponding topical clusters.</p

Summary statistics of 14 leading countries in nuclear fusion research.

All values are real numbers as we count the number of papers by the fractional counting method. Ratio is the proportion of collaborative papers to total papers.</p

Schematics of the fractional counting method for publication and collaboration counts.

Two matrices, the fractional publication counts by countries At and the topic distributions of papers Bt, were extracted from the document set of year t. (1) represents the fractional publication counts by topics at year t. For further analysis, based on the hierarchical tree of clusters in Fig 2, the fractional publications by 41 topics are grouped into five topical clusters: material, plasma, device, diagnostics, and simulation. Rt is the aggregated matrix and is transposed in the figure to match with the hierarchical tree of 41 clusters. (2) The country profile of a paper is transformed into a collaboration matrix W1, which was distributed over the five topical clusters by weights. For each year, by aggregating the collaboration matrices of all published papers, we had five fractional collaboration matrices.</p

Ranks of normalized revealed comparative advantages for the top 14 countries.

Rank series of the countries are smoothed with LOESS (locally estimated scatterplot smoothing) and colored by the topical clusters.</p

Synthesis of Phase-Pure Interpenetrated MOF-5 and Its Gas Sorption Properties

For the first time, phase-pure interpenetrated MOF-5 (1) has been synthesized and its gas sorption properties have been investigated. The phase purity of the material was confirmed by both single-crystal and powder X-ray diffraction studies and TGA analysis. A systematic study revealed that controlling the pH of the reaction medium is critical to the synthesis of phase-pure 1, and the optimum apparent pH (pH*) for the formation of 1 is 4.0−4.5. At higher or lower pH*, [Zn2(BDC)2(DMF)2] (2) or [Zn5(OH)4(BDC)3] (3), respectively, was predominantly formed. The pore size distribution obtained from Ar sorption experiments at 87 K showed only one peak, at ∼6.7 Å, which is consistent with the average pore size of 1 revealed by single crystal X-ray crystallography. Compared to MOF-5, 1 exhibited higher stability toward heat and moisture. Although its surface area is much smaller than that of MOF-5 due to interpenetration, 1 showed a significantly higher hydrogen capacity (both gravimetric and volumetric) than MOF-5 at 77 K and 1 atm, presumably because of its higher enthalpy of adsorption, which may correlate with its higher volumetric hydrogen uptake compared to MOF-5 at room temperature, up to 100 bar. However, at high pressures and 77 K, where the saturated H2 uptake mostly depends on the surface area of a porous material, the total hydrogen uptake of 1 is notably lower than that of MOF-5

Polycondensation of Butenediol: Synthesis of Telechelic 2-Butene-1,4-diol Oligomers

The catalytic condensation of cis-2-butene-1,4-diol with CpRu(MQA)(C3H5) (Cp = cyclopentadienyl, MQA = 4-methoxyquinoline-2-carboxylate) generates poly(2-butenediol), an unsaturated telechelic polyether diol with molecular weights between 400 and 4600 g/mol. This Ru(IV) allyl catalyst enchains 2-butene-1,4-diol primarily as the linear trans-2-butenyl ether (92%) along with vinyl branches (8%). These telechelic oligomers are useful chain extenders and macromonomers, as demonstrated by their use in the synthesis of poly(lactide)-b-poly(butenediol)-b-poly(lactide) triblock copolymers. Model studies support a proposed mechanism involving the formation of Ru(IV) allyl intermediates from allylic alcohols and chain growth by selective nucleophilic displacement at the terminus of the Ru(IV) allyl to generate trans-2-butenyl ether linkages

A facile preparation method for nanosized MOFs as a multifunctional material for cellular imaging and drug delivery

<p>Tb-based metal-organic framework nanoparticles (Tb-MOF NPs) with good colloidal stability and stable fluorescence properties in an aqueous solution were prepared by a simple mechanical grinding of Tb-MOF with a biocompatible polymer surfactant (F127). The characteristic fluorescence property of Tb-MOF NPs allowed us to use this nanomaterial as a cell imaging probe. Efficient cellular uptake of Tb-MOF NPs apparently via an energy-dependent endocytosis was observed by confocal laser scanning microscopy. By taking advantage of the porous nature of the Tb-MOF NPs an anticancer drug (doxorubicin) was successfully loaded and delivered to kill cancer cells to demonstrate their usage as a drug delivery vehicle. This simple grinding method afforded a nanosized, multifunctional biomaterial that was used for cell imaging and drug delivery, and it can be extended to other MOFs to widen their applications.</p