Burke McCormack (portersalmon0)

Several MOF polymorphs exhibit enhanced properties compared to their previously known structures, motivating the development of polymorphic control methods. Here, we study polymorphism in the ZIF-8/ZIF-L system as a function of metal ligand ratio during synthesis and show a significant shift in the phase transition point towards ZIF-8 with addition of dilute polyethylene oxide during synthesis. Computational results suggest a simple pathway for controlling MOF polymorphism where the choice of polymer can be guided via first-principles simulations.Herein, we simply synthesized intrinsic fluorescent polydopamine nanoparticles (PDA NPs) in sodium hydroxide solution (NaOH, pH 11), and constructed a new fluorescence nanoplatform for the detection of alkaline phosphatase (ALP) using PDA NPs as an effective signal reporter. OTX008 concentration was constructed by the combination of enzymatic hydrolysis of ALP to the substrate l-ascorbic acid-2-phosphate (AA2P) and the chemical redox reaction between l-ascorbic acid (AA) and mercury ion (Hg2+). The fluorescence of PDA NPs could be effectively quenched by Hg2+ through the coordination effect between Hg2+ and the functional groups on the surface of PDA NPs. However, the quenching effect was greatly inhibited by the addition of AA into the solution. Based on this point, the activity of ALP could be monitored by hydrolysis of the substrate AA2P to AA and the fluorescence output of PDA NPs. The nanoplatform exhibited high sensitivity and desirable selectivity for ALP detection. With a wide linear range of 0 to 18 U L-1, a detection limit of 0.4 U L-1 was achieved using the developed nanosensor. The proposed method could not only be used to screen the inhibitor of ALP but also be used to detect ALP activity in human serum samples successfully. Moreover, the strategy can easily be expanded to determining other kinds of enzymes participating in AA-generation reactions.Photocatalytic hydrogen production from water is a promising method to obtain clean energy in the future. In this work, the sulfated TiO2 photocatalyst is successfully constructed in situ via a soft-templated method for photocatalytic water splitting to produce hydrogen. The content of sulfate species in TiO2 can be tuned by changing the amount of the surfactant. The photocatalyst with the appropriate content of sulfate ions exhibits an apparent quantum efficiency (AQE) of 3.9% at 365 nm and a high hydrogen production rate of 24.32 mmol h-1 g-1, which is 1.65 times that of commercial TiO2 (P25). The optimized photocatalyst has excellent photocatalytic activity for hydrogen evolution benefitting from the presence of sulfate ions on the surface of TiO2, large surface area and oxygen vacancies, which facilitates the rapid migration of photo-generated electrons to its surface and the improvement of the separation efficiency of photo-generated carriers. This work may inspire the rational design and the development of high-efficiency photocatalysts.The stability constants of Mn2+ complexes with ligands containing a trans-1,2-cyclobutanediamine spacer functionalized with picolinate and/or carboxylate functions were determined using potentiometric titrations (25 °C, 0.1 M KCl). The stability constant of the complex with a hexadentate ligand containing four acetate groups (L14-, log KMnL = 10.26) is improved upon replacing one (L24-, log KMnL = 14.71) or two (L34-, log KMnL = 15.81) carboxylate groups with picolinates. The [Mn(L1)]2- complex contains a water molecule coordinated to the metal ion in aqueous solutions, as evidenced by 1H NMRD studies and 17O chemical shifts and transverse relaxation rates. The 1H relaxivities determined at 60 MHz (3.3 and 2.4 mM-1 s-1 at 25 and 37 °C, respectively) are comparable to those of monohydrated complexes such as [Mn(edta)]2-. The exchange rate of the inner-sphere water molecule (k = 248 × 106 s-1) is slightly lower than that of the edta4- analogue. DFT calculations (M11/def2-TZVP) suggest th