An Essay on Synthetic Chemistry of Colloidal Nanocrystals

The central goal of synthetic chemistry of colloidal nanocrystals at present is to discover functional materials.Such functional materials should help mankind to meet the tough challenges brought by the rapid depletion of natural resources and the signifi cant increase of population with higher and higher living standards.With this thought in mind,this essay discusses the basic guidelines for developing this new branch of synthetic chemistry,including rational synthetic strategies,functional performance,and green chemistry principles.

Synthesis and Characterization of Tb^(3+)-Trimesic Acid Fluorescence System

The luminescent complex of Tb (3+)-trimesic acid was synthesized in an alcohol and water mixed solvent. The chemical components of the complex TbL·5H_2O was characterized by the element analysis,thermal analysis and FTIR. The results of the XRD patterns and SEM photographs indicate that the complex is composed of a lot of bar-shaped crystal grain with 5～10 μm long. The results of the photoluminescence show that the complex emitted the characteristic green fluorescence of Tb (3+).

Synthetic and structural chemistry of hexacobalt cluster compounds——Ⅱ. Preparation and structure of Co_6(μ_3-S)_8(Ph_2PCH_2P(O)Ph_2)_6

Co_6(μ_3-S)_8(Ph_2PCH_2P(O)Ph_2)_6, MW=3012.5, space group R, has the hexagonal parameters, a=26.764(10), c=16.979 (10), V=10532.8~3, Z=3. Mo Kα radiation, λ= 0.71069, Dc=1.425 g/cm^3, μ=9.94 cm^(-3), F(000)=4650, R=0.073 and Rw=0.077 for 1965 observed unique reflections with I>3σ(I). The molecular structure consists of a distorted octahed- ral Co_6-core. The Co-Co and Co-S distances fall in the range of 2.805-2.838 and 2.213-2.253, respectively.

Synthetic and structural chemistry of nickel(Ⅱ) complexes containing dithiolato and phosphine ligands Ⅰ. Preparation and crystal structure of Ni_2(PPh_3)_2(edt)_2

A nickel(Ⅱ) complex containing both dithiolato and phosphine ligands, Ni_2(PPh_3)_2(edt)_2 (edt = SCH_2CH_2S^(2-)), has been prepared and characterized by X-ray diffration. The complex crystallizes in the triclinic system, space group P-1, with a = 10.693(3), b = 17.457 (6), c = 10.606 (3)A, α= 102.84(2), β = 96.49 (2), γ = 82.56(3)°; V = 1906.8 A^3; D_c = 1.439g.cm^(-3) for Z=2; the final con- ventional R was 0.052 based on 3338 observed reflections. Nickel atoms are linked by two sulfur atoms from two edt ligands with the Ni--Ni distance of 2.893 A, and each Ni atom is coordinated by one phosphorus atom and three sulfur atoms with a square-planar geometry, where the average: length of Ni--S bond is 2.180 A and Ni--P bond 2.188 A. The UV-Vis and ~1H NMR spectra have also been recorded.

Late-stage modification of bioactive compounds:Improving druggability through efficient molecular editing

Synthetic chemistry plays an indispensable role in drug discovery,contributing to hit compounds identification,lead compounds optimization,candidate drugs preparation,and so on.As Nobel Prize laureate James Black emphasized,“the most fruitful basis for the discovery of a new drug is to start with an old drug”1.Late-stage modification or functionalization of drugs,natural products and bioactive compounds have garnered significant interest due to its ability to introduce diverse elements into bioactive compounds promptly.Such modifications alter the chemical space and physiochemical properties of these compounds,ultimately influencing their potency and druggability.To enrich a toolbox of chemical modification methods for drug discovery,this review focuses on the incorporation of halogen,oxygen,and nitrogen—the ubiquitous elements in pharmacophore components of the marketed drugs—through late-stage modification in recent two decades,and discusses the state and challenges faced in these fields.We also emphasize that increasing cooperation between chemists and pharmacists may be conducive to the rapid discovery of new activities of the functionalized molecules.Ultimately,we hope this review would serve as a valuable resource,facilitating the application of late-stage modification in the construction of novel molecules and inspiring innovative concepts for designing and building new drugs.

基于集群纳米机器技术和合成生命化学的动态人工细胞

人工细胞构筑在基础和应用生物技术研究中具有重要意义.然而,现有的人工细胞区室化的构建往往是静态的,与动态的自然细胞存在差距.基于此,我们通过前沿磁控纳米机器技术和无细胞转录-翻译溶液化学系统来构筑一个可编程控制的动态人工细胞.通过物理控制二维或三维磁场的方向、强度和频率,基于不同形态的DNA和磁性颗粒产生不同形貌的簇、链和片等区室化排列.这些不同形貌的动态人工细胞结构呈现出特殊的转录-翻译性能.集群机器人技术和合成生命化学的融合利用可为构筑富有想象力的人工细胞提供新的研究范式,并为生命过程的理解和颠覆性的生物应用提供重要支撑.

Methylated and thiolated arsenic species for environmental and health research——A review on synthesis and characterization

Hundreds of millions of people around the world are exposed to elevated concentrations of inorganic and organic arsenic compounds, increasing the risk of a wide range of health effects. Studies of the environmental fate and human health effects of arsenic require authentic arsenic compounds. We summarize here the synthesis and characterization of more than a dozen methylated and thiolated arsenic compounds that are not commercially available. We discuss the methods of synthesis for the following14 trivalent（Ⅲ） and pentavalent（） arsenic compounds： monomethylarsonous acid（MMA~Ⅲ）, dicysteinylmethyldithioarsenite（MMA~Ⅲ（Cys）_2）, monomethylarsonic acid（MMA~Ⅴ）,monomethylmonothioarsonic acid（MMMTAⅤ） or monothio-MMA~Ⅴ, monomethyldithioarsonic acid（MMDTA~Ⅴ） or dithio-MMA~Ⅴ, monomethyltrithioarsonate（MMTTA~Ⅴ） or trithio-MMA~Ⅴ,dimethylarsinous acid（DMA~Ⅲ）, dimethylarsino-glutathione（DMA~Ⅲ（SG））, dimethylarsinic acid（DMA~Ⅴ）, dimethylmonothioarsinic acid（DMMTA~Ⅴ） or monothio-DMAⅤ, dimethyldithioarsinic acid（DMDTA~Ⅴ） or dithio-DMA~Ⅴ, trimethylarsine oxide（TMAO~Ⅴ）, arsenobetaine（AsB）, and an arsenicin-A model compound. We have reviewed and compared the available methods,synthesized the arsenic compounds in our laboratories, and provided characterization information. On the basis of reaction yield, ease of synthesis and purification of product, safety considerations, and our experience, we recommend a method for the synthesis of each of these arsenic compounds.

A universal strategy for fast,scalable,and aqueous synthesis of multicomponent palladium alloy ultrathin nanowires

Noble metal alloy nanowires(NWs)with ultrathin diameters(2–3 nm)and precisely controllable elemental compositions have attracted dramatically growing attention for(electro)catalysis.Despites numerous achievements in past two decades,noble metal alloy NWs are mostly synthesized with the traditional oil-phase methods that suffer from some undesirable drawbacks.Here,we report a general strategy for fast,scalable,and aqueous synthesis of multicomponent Pd-based alloy ultrathin NWs with an average diameter of 2.6 nm,ranging from bimetallic PdM(PdFe,PdCo,PdNi,PdCu,PdZn,PdRu,PdRh,PdAg,PdCd,PdIr,PdPt,PdAu)and binary PdS/PdP NWs,to trimetallic PdM1M2 NWs(PdAuCu,PdCoNi,PdCuZn,PdCuNi,PdAgCu,PdAuCu,PdRuAg,PdAuRu,and PdPtAu),and to tetrametallic PdM1M2M3 NWs(PdAuAgCu,PdCoCuNi,PdAuCuNi,PdPtAuCu,and PdIrPtAu).The key to the success of this aqueous synthesis is the utilization of N2H4 as the extremely strong reducing agent that directs the synchronous reduction and anisotropic nucleation growth of multicomponent Pd alloy NWs along nanoconfined columnar phase assembled with amphiphilic dioctadecyldimethylammonium chloride.As-resultant Pd-based alloy ultrathin NWs exhibit multiple structural and compositional synergies,which remarkably optimize the removal of poisoning ethoxy intermediates and thus improve electrocatalytic performance towards ethanol oxidation reaction(EOR).Among them,tetrametallic PdAuCuNi alloy ultrathin NWs hold a high EOR activity of 5.14 A mg-1 Pd and a low activation energy of 13.1 kJ mol^-1,both of which are much better than its counterpart catalysts alloyed with less elements.This work represents an important advance in precise aqueous synthesis of multicomponent noble metal alloy ultrathin NWs as the high-performance electrocatalysts for various targeted applications.