Shields up! Post-synthetic modification of the secondary building units in the metal-organic framework UiO-66 (Zr6O4(OH)4(O2CR)12) by dehydration and subsequent grafting of LiOtBu yields a solid Li(+) electrolyte with a conductivity of 1.8×10(-5) S cm(-1) at 293 K. As the grafting leads to screening of the anionic charge, the activation energy for ionic conduction is significantly lower than when Li(+) is introduced through deprotonation.
Broadband and white-light emitting materials are sought after for applications such as phosphors and LEDs. Some twodimensional (2D) halide perovskites are promising candidates in this realm. Nevertheless, optimizing their photoluminescence quantum efficiency (PLQY) is highly challenging. Herein, we show a new strategy for optimizing the efficiency of the broadband emission of 2D halide perovskites. Specifically, we show that by a combination of halide bonds and halide mixing, the PLQYs of a novel family of materials with the formula (Br-PEA) 2 PbBr x Cl 4−x (Br-PEA = 4-bromo phenethylammonium) can be improved by one order of magnitude, from 3 to 25%; this approach could be useful to many other 2D perovskites.
The facile preparation of β-diketiminate gallium amides with general formulas of either LGa(NHR) 2 {L = [HC{C(Me)N-(Ar)} 2 ]-, Ar = 2,6-iPr 2 C 6 H 3 ; R = Et (1), iPr (2), nBu (3), Ph (4)} or LGa(NHR)Cl [R = tBu (5); Et (6)] was accomplished by the reaction of LGaCl 2 with the lithium salt of the corresponding amine in 1:2 (1-4) or 1:1 (5, 6) molar ratios. Compounds 1-6 are useful synthons for further synthesis, as the amide substituents are excellent leaving groups, and the resulting amines can be cleanly and easily removed from the reaction matrix. To demonstrate this, compounds 1 and 5 were treated with ethanol, leading to the alcoholysis products LGa(OEt) 2
The unique alumophosphite reagent LAl(SH)(mu-O)P(OEt)2 was prepared and used for the synthesis of the heterobimetallic alumophosphites [{kappa2-S,P-LAl(S)(mu-O)P(OEt)2}2Zn] and [{kappa4-S,O,O-LAl(SLi)(mu-O)P(OEt)2}2]. The first contains a rare example of two carbon-free five-membered heterocycles (Al-S-Zn-P-O) connected in a spiro fashion through the zinc atom, whereas the second possesses an unknown example of a coordination environment of a phosphite unit M-O-P(mu-OEt)2M with an uncoordinated lone electron pair on the phosphorus center.
The reaction of ZrCl with 2',3',5',6'-tetramethylamino-p-terphenyl-4,4″-dicarboxylic acid (Htpdc-4CHNH·3HCl) in the presence of NaF affords ZrO(OH)F(tpdc-4CHNH·3HCl) (1), which is a new member of the ZrO(OH)(dicarboxylate linker) or UiO-68 family, and exhibits high porosity with BET and Langmuir surface areas of 1910 m/g and 2220 m/g, respectively. Remarkably, fluoride ion incorporation in the zirconium clusters results in increased thermal stability, marking the first example of enhancement in the stability of a UiO framework by this defect-restoration approach. Although material 1 features four alkylamine groups on each organic linker, the framework does not exhibit the high CO uptake that would be expected for reaction between CO and the amine groups to form carbamic acid or ammonium carbamate species. The absence of strong CO adsorption can likely be attributed to protonation at some of the amine sites and the presence of counterions. Indeed, exposure of material 1 to acetonitrile solutions of the organic bases 1,8-bis(dimethylamino)naphthalene (DMAN) or trimethylamine, affords a partially deprotonated material, which exhibits enhanced CO uptake. Exposure of basic amine sites also facilitates the postsynthetic chelation of copper(I) ([Cu(MeCN)]·CFSO) to yield material 2 with an enhanced CO uptake of 4 wt % at 0.15 bar, which is double that of the parent framework 1.
Calcium scaling is a serious problem
encountered in the oil and
gas industry because it is common that brines produced alongside oil
and gas exhibit high concentrations of calcium ions, among others,
which is expensive to remedy. The precipitation of calcium salts on
the internal wall of the pipelines may occur because of the physical
and chemical changes as fluids are produced from downhole to surface
facilities. Although different researchers have address scaling and
corrosion in the oil and gas industry, there are few reports in the
literature relating the corrosion and scaling phenomena simultaneously.
Despite there being indications that scales may produce corrosion
problems, affecting the mechanical integrity of the infrastructure,
there is minimal research in the literature addressing such relations.
Previous studies presented aluminum alloys as excellent and reliable
materials for applications in the petroleum industry, such as drilling
activities. In this work, we evaluate the corrosion behavior of steel
and aluminum alloys under highly scaling environments using supersaturated
brines. Our results show that the presence of calcium carbonate and
calcium sulfate as a scaling environment increases the corrosion rates
for aluminum alloys and carbon steel; however, the same environments
do not affect the corrosion behavior of stainless steel.
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.