Amine-Responsive Disassembly of AuI -CuI Double Salts for Oxidative Carbonylation.

A sensitive amine-responsive disassembly of self-assembled AuI -CuI double salts was observed and its utilization for the synergistic catalysis was enlightened. Investigation of the disassembly of [Au(NHC)2 ][CuI2 ] revealed the contribution of Cu-assisted ligand exchange of N-heterocyclic carbene (NHC) by amine in [Au(NHC)2 ]+ and the capacity of [CuI2 ]- on the oxidative step. By integrating the implicative information coded in the responsive behavior and inherent catalytic functions of d10 metal complexes, a catalyst for the oxidative carbonylation of amines was developed. The advantages of this method were clearly reflected on mild reaction conditions and the significantly expanded scope (51 examples); both primary and steric secondary amines can be employed as substrates. The cooperative reactivity from Au and Cu centers, as an indispensable prerequisite for the excellent catalytic performance, was validated in the synthesis of (un)symmetric ureas and carbamates.

Bimetallic capture sites on porous La/Bi hydroxyl double salts for efficient phosphate adsorption: Multiple active centers and excellent selective properties.

The rapid development of modern agriculture aggravated water eutrophication. Therein, efficient and selective removal of phosphorus in water is the key to alleviating eutrophication. It is well known that lanthanum (La)-based material is a kind of outstanding phosphorus-locking agent. Therefore, improving the property of La-based adsorbents is a hot topic in this field. Herein, novel porous hydroxyl double salts (La/Bi-HDS) with bimetallic capture sites were prepared. The experimental result shows that La/Bi-HDS could maintain the high removal rate in the solution with a higher concentration of competing ions and the maximum P adsorption quantity of La/Bi-HDS attains 168.12 mg/g. Mechanistic studies supported by density functional theory (DFT) calculation demonstrate that introducing Bi3+ optimizes the electronic structure of La, reducing adsorption energy. In addition, the surface analysis shows that the introduction of Bi, which increases the pore size and volume of the material, improves the utilization efficiency of the active site. In a word, the introduction of Bi element as a strategy of killing two birds with one stone successfully improved the performance of La-based adsorbent. It provided a new direction for developing an efficient phosphorus-locking agent.

Centimeter-Scale Pillared-Layer Metal-Organic Framework Thin Films Mediated by Hydroxy Double Salt Intermediates for CO2 Sensor Applications.

Fabrication of metal-organic framework (MOF) thin films over macroscopic surface areas is a subject of great interest for gas sensor application platforms such as optics and microelectronics. However, a direct synthesis of MOF films at ambient conditions, in particular pillared-layer MOF films due to their anisotropic structures, remains a significant challenge. Herein, we demonstrate for the first time a facile construction of dense and continuous pillared-layer MOF thin films on a centimeter scale via an aluminum-doped zinc oxide template and hydroxy double salt (HDS) intermediates at room temperature. A series of Cu(II)-based pillared MOFs with different 1,4-benzenedicarboxylic acid (bdc) ligands were explored for optimizing MOF film formation for CO2 sensor applications. Nonpolar ligands with lower water solubility preferentially formed crystalline pillared MOF structures from HDS intermediates. A Cu2(ndc)2(dabco) (ndc = 1,4-naphthalene-bdc; dabco = 1,4-diazabicyclo[2.2.2]octane) MOF demonstrated the most dense and uniform film growth with micrometer thickness over one square centimeter area. This synthetic approach for growing Cu2(ndc)2(dabco) MOF thin films was successfully translated toward two sensing platforms: a quartz crystal microbalance and an optical fiber sensor. These Cu2(ndc)2(dabco) MOF-coated sensors displayed sensitivity toward CO2 and response/recovery time on the scale of seconds, even at moderate humidity levels. This work provides a road map for producing continuous and anisotropic crystalline MOF thin films over a centimeter scale area on various substrates, which will greatly facilitate their utilization in MOF-based sensor devices, among other applications.

Thermodynamic Description of Dilution and Dissolution Processes in the MgCl2-CsCl-H2O Ternary System.

Thermodynamic data on the properties of the water-based electrolyte systems are very valuable for fundamental physical chemistry and for industrial applications. The missing data both on the dilution and dissolution enthalpies for the ternary CsCl-MgCl2-H2O mixed electrolyte system were investigated by means of the calorimetry method. The dilution calorimetry was performed at 298 K for the set of solutions from diluted to concentrated at constant ratio Cs+/Mg2+=1.8. The relative partial molar enthalpies, ideal, total, and excess ones were calculated. By means of the dissolution calorimetry, the standard enthalpies of formation, the enthalpies, and entropies for the double salt formation from simple salts were evaluated. The results obtained indicate that entropy as the major factor affecting the formation of the joint compound, both in the liquid and solid phases. These data can be implemented in thermodynamic databases and allow for accurate thermodynamic calculations for the salts extraction from natural water sources and for its possible application as thermochemical energy storage.

Synthesis and Characterization of Double-Salt Herbicidal Ionic Liquids Comprising both 4-Chloro-2-methylphenoxyacetate and trans-Cinnamate Anions.

The synthesis and characteristics are presented of novel double-salt herbicidal ionic liquids (DSHILs) that contain 4-chloro-2-methylphenoxyacetate and trans-cinnamate anions. In the designed synthesis, an anion of natural origin and a herbicidal anion were combined with an amphiphilic bisammonium cation to obtain new DSHILs with high herbicidal activity while high biocompatibility is maintained. The NMR and HRMS spectral analysis confirmed that the target structures were formed. Furthermore, HPLC analyses indicated that, as assumed, both anions were present in equimolar amounts. Experiments regarding the herbicidal effectiveness confirmed that the synthesized DSHILs exhibited high biological activity. The solutions of DSHILs applied during greenhouse studies were characterized by a low contact angle (approx. 55-67°) and surface tension (approx. 32-35 mN m-1 ), which facilitated the contact of the active substance with the plant surface and penetration of the herbicide into the plant tissues.

Thermal treatment and ammoniacal leaching for the recovery of valuable metals from spent lithium-ion batteries.

The recycling of spent commercial lithium-ion batteries (LIBs) generates numerous environmental and economic benefits. In this research, a thermal treatment-ammoniacal leaching process is proposed to recover valuable metals from cathode active powder. Based on the thermal behavior by TG-DSC analysis, the cathode active powder is calcined at 300 °C and 550 °C in air atmosphere, and the crystalline phase characterization indicates that a new phase of Co3O4 appears in the cathode active powder calcined at 550 °C, which signifies that the layer structure of LiCoO2 collapses. The valence of manganese increases to form Li4Mn5O12 in spinel structure of LiMn2O4. Using calcined cathode powder as feed material, ammoniacal leaching is carried out in (NH4)2SO4 -(NH4)2SO3 solution. Under the optimum conditions, Ni, Co, Mn and Li can be completely leached out with efficiencies of 98%, 81%, 92% and 98%, respectively. However, with the increase of ammonia concentration, the leaching efficiency of Mn decreases dramatically to 4% due to the formation of double salts. It is found that Co and Mn can be precipitated into residues in the form of (NH4)2Co(SO4)2·H2O, (NH4)2Mn(SO3)2·H2O and (NH4)2Mn(SO4)2·6H2O under different leaching parameters. Based on the corresponding relationship between the leaching efficiency and phase evolution of object element, selective leaching can be achieved by controlling the formation of double salts.