环二肽的自组装及其荧光性能

环二肽由两个氨基酸通过肽键环合形成,在氢键相互作用驱动下具有较强的自组装倾向.本工作研究了c-SF,c-SY,c-SH及c-DF等四种环二肽的自组装行为和组装体的荧光特性.实验结果表明,c-SH为无规卷曲而其他三种环二肽均采取β-sheet二级结构,且除c-SH未形成明显组装体外,其他三种环二肽均形成不同尺寸的纳米纤维.荧光光谱检测发现环二肽在不同波长的激发下存在多个不同的荧光发射峰;对于c-SH,侧链咪唑基官能团与Zn（II）配位可以增大荧光发射的强度;对于c-SY,侧链酚羟基的氧化也可以增强荧光强度.推测在氢键作用的驱动下环二肽分子可以逐个堆叠形成纳米纤维,自组装导致的分子聚集和分子的侧链结构均可使环二肽具有可调变的荧光性能.     

Nd(OTf)3-catalyzed intramolecular-intermolecular cascade cyclization reaction: An access to phenanthro[9,10-b]furan derivatives

An intramolecular-intermolecular cascade cyclization reaction via multi metal-carbene intermediates has been developed. This reaction uses catalytic amount of Nd(OTf)₃, which actives both alkyne and aldehyde moieties. This protocol provides a novel strategy for the synthesis of phenanthro[9,10-b]furans.     

Stability,antibacterial ability,and inhibition of “zinc burning” of amitrole as thermal stabilizer for transparent poly(vinyl chloride)

Journal of Thermal Analysis and Calorimetry - Amitrole is reported as a novel kind of transparent poly(vinyl chloride) (PVC) thermal stabilizer that has both excellent inhibition of “zinc...     

The block combustion,high char residues and smoke restrain effect of nano-FeSnO(OH)5 on polyvinyl chloride

Journal of Thermal Analysis and Calorimetry - Nanoscale and cubic-shaped FeSnO(OH)5 (ITOH) flame retardant was synthesized by co-precipitation method and characterized by X-ray diffraction and...     

Synergistic effects of mono-component intumescent flame retardant grafted with carbon black on flame retardancy and smoke suppression properties of epoxy resins

Journal of Thermal Analysis and Calorimetry - A mono-component intumescent flame retardant named pentaerythritol phosphate melamine salt (PPMS) was grafted on the surface of carbon black (CB) to...     

Dehydrogenative Silylation of Alkenes for the Synthesis of Substituted Allylsilanes by Photoredox,Hydrogen‐Atom Transfer,and Cobalt Catalysis

A synergistic catalytic method combining photoredox catalysis, hydrogen‐atom transfer, and proton‐reduction catalysis for the dehydrogenative silylation of alkenes was developed. With this approach, a highly concise route to substituted allylsilanes has been achieved under very mild reaction conditions without using oxidants. This transformation features good to excellent yields, operational simplicity, and high atom economy. Based on control experiments, a possible reaction mechanism is proposed.