Computation-led design of pollutant gas sensors with bare and carbon nanotube supported rhodium alloys

Quantum chemical study has been performed on finite-sized bi-metallic Rh3M alloys, M = Ag, Ir, Pd, Pt, Au, derived from magic cluster, Rh4. Bond length of C–O and N–O are noticed to be elongated in the presence of rhodium alloy clusters. CO2 and NO2 gases are found to be highly adsorbed on Rh3M clusters, which is confirmed by stretching frequency of C–O and N–O. DFT evaluated dipole moment and electronic charge redistribution suggests the sensing capability of CO2 and NO2 gases by Rh3M clusters which is further confirmed by the calculated HOMO–LUMO gap. Mixed rhodium alloy clusters supported on single-wall carbon nanotube (SWCNT) exhibits much higher ability to sense CO2 and NO2. On the other hand, SWCNT@Rh3M shows higher catalytic activity for the activation of CO2 and NO2 in comparison to bare Rh3M because of the higher electronic charge redistribution in the case of SWCNT@Rh3M. In case of SWCNT-supported gas adsorbed clusters, p electrons play a major role in bonding.     

Synthesis and biological evaluation of new mono naphthalimide platinum(IV) derivatives as antitumor agents with dual DNA damage mechanism

Naphthalimide has emerged as an interesting DNA intercalator and possessed attracting antitumor properties. In this context, naphthalimide group was linked to platinum(IV) core to construct a series of new mono naphthalimide platinum(IV) derivatives. The title compounds exert effective antitumor activities to the tested tumor cells lines in vitro, especially the one with propionyl chain displays comparable or even better bioactivities than platinum(II) reference drugs cisplatin and oxaliplatin. Moreover, the mono naphthalimide platinum(IV) derivative displays comparable tumor growth inhibitory competence against CT26 xenograft tumors in BALB/c mice in vivo without severe toxic effects in contrast to oxaliplatin. A dual DNA damage mechanism was proven for the title complex. Both naphthalimide ligand and the liberated platinum(II) moiety could generate DNA lesions to tumor cells synergistically and active the apoptotic pathway by up-regulating the expression of caspase 9 and caspase 3. Meanwhile, the conversion of platinum(II) drug into tetravalent form by incorporating naphthalimide moiety increases the uptake of platinum in whole cells and DNA remarkably. All these facts might be the factors for the title platinum(IV) complexes to overcome platinum(II) drug resistance. Additionally, the mono naphthalimide platinum(IV) complex could interact with human serum albumin by hydrogen bond and van der Waals force which would further influence their storage, transport and bioactivities.     

Toughening a Self-Healable Supramolecular Polymer by Ionic Cluster-Enhanced Iron-Carboxylate Complexes

Supramolecular polymers that can heal themselves automatically usually exhibit weakness in mechanical toughness and stretchability. Here we exploit a toughening strategy for a dynamic dry supramolecular network by introducing ionic cluster-enhanced iron-carboxylate complexes. The resulting dry supramolecular network simultaneous exhibits tough mechanical strength, high stretchability, self-healing ability, and processability at room temperature. The excellent performance of these distinct supramolecular polymers is attributed to the hierarchical existence of four types of dynamic combinations in the high-density dry network, including dynamic covalent disulfide bonds, noncovalent H-bonds, iron-carboxylate complexes and ionic clustering interactions. The extremely facile preparation method of this self-healing polymer offers prospects for high-performance low-cost material among others for coatings and wearable devices.     

荧光碳点的制备及银离子辅助的点亮型识别青霉胺

以半胱氨酸为原料,通过一步热解法制备了荧光碳点（CDs）,并采用透射电镜（TEM）、动态光散射（DLS）、X射线能谱分析（XPS）、紫外可见吸收光谱（UV-Vis）和荧光光谱（FL）对其进行了表征。结果表明该碳点平均尺寸为3.12 nm,且表现出了良好的荧光特性。银离子能够与碳点结合进而通过光诱导的电子转移有效猝灭碳点的荧光。青霉胺得益于其与重金属离子的配位作用,能够与银离子结合使得后者离开碳点表面从而实现荧光恢复。基于此,我们建立了银离子辅助的碳点荧光点亮型识别青霉胺的新方法。该方法的线性范围为8~500 μmol·L^-1,检出限为5.62 μmol·L^-1。该荧光体系用于尿液样品测定,回收率在97.17%~102.05%范围内。     

Palladium‐Catalyzed Asymmetric [4+3]‐Cyclization Reaction of Fused 1‐Azadienes with Amino‐trimethylenemethanes: Highly Stereoselective Construction of Chiral Fused Azepines

Summary of main observation and conclusion A Pd-catalyzed asymmetric aromative[4+3]-cyclization reaction of amino-trimethylenemethanes(TMM,1d,ip3-oles)with fused 1-azadienes has been developed.This method enables access to the synthetically importance and biologically active benzofuran fused azepines and indeno-azepines in excellent efficiency and stereoselectivity(up to 95%yield,99%ee,>19:1 dr).     

以9，10-双(咪唑基)蒽为配体的锌配合物的合成、晶体结构和荧光性质

以9,10-双（咪唑基）蒽（DIA）和硝酸锌为原料,分别与对苯二甲酸（H₂bdc）、二苯甲酮-4,4''-二羧酸（H₂cdc）、反式-1,4-环己二甲酸（H₂chdc）在溶剂热条件下反应,得到3个结构不同的配位聚合物[Zn₂（DIA）（bdc）₂]_n（1）、{[Zn（DIA）（cdc）]·H₂O}_n（2）和[Zn（DIA）（chdc）]_n（3）。对它们进行了X射线单晶衍射分析、元素分析、红外光谱分析和热重分析。单晶结构分析显示,配合物1是第一例拥有三维（4,7）-连接的{3².4.5².6}{3².4⁸.5⁴.6⁵.7²}₂拓扑结构;配合物2具有二维格子状结构,层与层之间通过O-H…O和π…π弱相互作用形成三维超分子结构;而配合物3具有二维两重贯穿的层状结构。结果说明有机羧酸的长度和刚柔性在配合物组装过程中起着非常重要的作用。此外,在室温下对3个配合物进行了荧光性质分析。     

All-solid-state BiVO4/ZnIn2S4 Z-scheme composite with efficient charge separations for improved visible light photocatalytic organics degradation

Constructing a Z-scheme is a significant approach to improve the separation of photogene rated carriers for effective organic pollutant degradation.Herein,a BiVO4/ZnIn2S4(BZ) Z-scheme composite was successfully synthesized,and applied to photodegrade methyl orange(MO) irradiated by a LED lamp.Anchoring the BiVO4 on the ZnIn2S4 nanoparticles promoted the separation of photogenerated electronholes and broadened the light response range.The detailed characterizations,including surface morphology,elements valence state,and photocurrent performance,demonstrated that the enhanced separation of photogenerated carriers was the pivotal reason for the enhanced photocatalysis reaction.Benefiting from the excellent photocatalytic characteristics,the 5% mass ratio of BZ composite presented the highest MO degradation rate of 0.00997 min^-1,which was 1.9 and 10.3 times greater than the virgin ZnIn2S4 and BiVO4,respectively.Furthermore,the BZ hybrid materials indicated a well photo-stability in the four recycling tests.     

Construction of diaminobenzoquinone imines via ferrocene-initiated radical reaction of benzoquinone with amines

A ferrocene-initiated radical reaction of benzoquinone with amines has been successfully developed for the direct access to diaminobenzoquinone imines in high yields,in which the comme rcially available and cheap ferrocene was employed as a radical initiator and TBHP was used as an oxidant.Moreover,this reaction could be achieved with low loading of ferrocene(0.5 mol%).This protocol is highly efficient with good substrate tolera nce and provides a new approach for the construction of benzoquinone imines with potential pharmaceutical interest.     

TiC/C core/shell nanowires arrays as advanced anode of sodium ion batteries

High-perfo rmance anodes of sodium ion batteries(SIBs)largely depends on rational architecture design and binder-free smart hybridization.Herein,we report TiC/C core/shell nanowires arrays prepared by a one-step chemical vapor deposition(CVD)method and apply it as the anode of SIBs for the first time.The conductive TiC core is intimately decorated with carbon shell.The as-obtained TiC/C nanowires are homogeneously grown on the substrate and show core/shell heterostructure and porous architecture with high electronic conductivity and reinforced stability.Owing to these merits,the TiC/C electrode displays good rate performance and outstanding cycling performance with a capacity of 135.3 mAh/g at 0.1 A/g and superior capacity retention of 90.14%after 1000 cycles at 2 A/g.The reported strategy would provide a promising way to construct binder-free arrays electrodes for sodium ion storage.