Manganese-Catalyzed Chemoselective Coupling of Secondary Alcohols,Primary Alcohols and Methanol

Herein, we report a manganese-catalyzed three-component coupling of secondary alcohols, primary alcohols and methanol for the synthesis of β,β-methylated/alkylated secondary alcohols. Using our method, a series of 1-arylethanol, benzyl alcohol derivatives, and methanol undergo sequential coupling efficiently to construct assembled alcohols with high chemoselectivity in moderate to good yields. Mechanistic studies suggest that the reaction proceeds via methylation of a benzylated secondary alcohol intermediate to generate the final product.     

Three-Component Multiblock 1D Supramolecular Copolymers of Ir(III) Complexes with Controllable Sequences

Multicomponent supramolecular block copolymers (BCPs) have attracted much attention due to their potential functionalities, but examples of three-component supramolecular BCPs are rare. Herein, we report the synthesis of three-component multiblock 1D supramolecular copolymers of Ir(III) complexes 1 – 3 by a sequential seeded supramolecular polymerization approach. Precise control over the kinetically trapped species via the pathway complexity of the monomers is the key to the successful synthesis of BCPs with up to 9 blocks. Furthermore, 5-block BCPs with different sequences could be synthesized by changing the addition order of the kinetic species during a sequentially seeded process. The corresponding heterogeneous nucleation-elongation process has been confirmed by the UV/Vis absorption spectra, and each segment of the multiblock copolymers could be characterized by both TEM and SEM. Interestingly, the energy transfer leads to weakened emission of 1 -terminated and enhanced emission of 3 -terminated BCPs. This study will be an important step in advancing the synthesis and properties of three-component BCPs.     

氮气浮选测定化妆品中的铅

Pb（Ⅱ）与I-、RB在酸性条件下能形成三元缔合物,该缔合物在有机相中溶解度大于在水中溶解度,通过附着在氮气气泡上而被浮选带入有机相,从而达到分离富集的效果。运用本法测量化妆品中痕量铅,回收率为96.3%—104.4%,RSD〈3%,平行性良好,精密度、准确度较高。     

Fe(ClO4)3· 6H2O: a mild and efficient catalyst for one-pot three component synthesis of β-acetamido carbonyl compounds under solvent-free conditions

A one-pot multi-component reaction for the synthesis of β-acetamido carbonyl compounds is reported. The reaction uses a variety of aldehydes, acetophenone derivatives or methyl acetoacetate, acetonitrile, and acetyl chloride in the presence of ferric perchlorate, a mild, efficient and inexpensive catalyst effective under solvent free conditions.     

Building Blocks and COFs Formed in Concert—Three-Component Synthesis of Pyrene-Fused Azaacene Covalent Organic Framework in the Bulk and as Films

A three-component synthesis methodology is described for the formation of covalent organic frameworks (COFs) containing extended aromatics. Notably, this approach enables synthesis of the building blocks and COF along parallel reaction landscapes, on a similar timeframe. The use of fragmental building block components, namely pyrene dione diboronic acid as aggregation-inducing COF precursor and the diamines o-phenylenediamine (Ph), 2,3-diaminonaphthalene (Naph), or (1R,2R)-(+)-1,2-diphenylethylenediamine (2Ph) as extending functionalization units in conjunction with 2,3,6,7,10,11-hexahydroxytriphenylene, resulted in the formation of the corresponding pyrene-fused azaacene, i.e., Aza-COF series with full conversion of the dione moiety, long-range order, and high surface area. In addition, the novel three-component synthesis was successfully applied to produce highly crystalline, oriented thin films of the Aza-COFs with nanostructured surfaces on various substrates. The Aza-COFs exhibit light absorption maxima in the blue spectral region, and each Aza-COF presents a distinct photoluminescence profile. Transient absorption measurements of Aza-Ph- and Aza-Naph-COFs suggest ultrafast relaxation dynamics of excited-states within these COFs.     

In-situ synthesis of TbAlO3/Tb3Al5O12/Tb2O3 three-component nanocomposite as a heterojunction photocatalyst with a green and eco-friendly approach

In-situ synthesis of TbAlO₃ (TAP)/Tb₃Al₅O₁₂ (TAG)/Tb₂O₃ three-component nanocomposite by sol–gel method using natural reactants and investigation of its photocatalytic activity can be considered eco-friendly aspects of this work. The bioactive components of natural compounds may play as a reductant and progress the process through auto-combustion sol–gel technique. It was found that Mulberry has more bioactive components than Capparis spinosa L., so nucleation overtook growth and produced finer particles with less agglomeration. Optical property studies represented a band gap at about 3.8 eV that is different from the amounts related to TAP and TAG. Hence, e^--h⁺ transfers in this nanocomposite were studied by estimation of energy levels of its constituents. According to findings, these components formed a UV-active photocatalyst with Type-I configuration to degrade organic pollutants. In other words, presence of Tb₂O₃ helped to benefit from properties of two ferroelectric compounds, that they have large band gaps, in photocatalytic reactions. After optimizing the photocatalytic parameters, maximum yield was obtained at about 94 %. Kinetics studies showed the photocatalytic process follows zero-order kinetics. In addition, the ^oOH was found as the most active promoter agent.