Optically Active, Amphiphilic Poly(<i>meta</i>-phenylene ethynylene)s: Synthesis, Hydrogen-Bonding Enforced Helix Stability, and Direct AFM Observation of Their Helical Structures
Optically active, amphiphilicpoly(meta-phenylene ethynylene)s (PPEa) bearing L- or D-alanine-derived oligo(ethylene glycol) side chains connected to the backbone via amide linkages were prepared by microwave-assisted polycondensation. PPEa's exhibited an intense Cotton effect in the π-conjugated main-chain chromophore regions in various polar and nonpolar organic solvents due to a predominantly one-handed
Supramolecular Helical Assemblies of Dirhodium(II) Paddlewheels with 1,4-Diazabicyclo[2.2.2]octane: A Remarkable Substituent Effect on the Helical Sense Preference and Amplification of the Helical Handedness Excess of Metallo-Supramolecular Helical Polymers
supramolecular helicalassemblies of a series of dirhodium(II) tetracarboxylate paddlewheels bearing chiral phenyl- or methyl-substituted amide-bound m-terphenyl residues with triethylene glycol monomethyl ether (TEG) or n-dodecyl tails through a 1:1 complexation with 1,4-diazabicyclo[2.2.2]octane (DABCO). The chiral dirhodium complexes with DABCO in CHCl3/n-hexane (1:1) form one-handed helical coordination
Organicnanotubes (ONTs) are tubular nanostructures composed of small molecules or macromolecules that have found various applications including ion sensor/channels, gas absorption, and photovoltaics. While most ONTs are constructed by self-assembly processes based on weak noncovalent interactions, this unique property gives rise to the inherent instability of their tubular structures. Herein, we report
有机纳米管 (ONT) 是由小分子或大分子组成的管状纳米结构,已发现各种应用,包括离子传感器/通道、气体吸收和光伏。虽然大多数 ONT 是通过基于弱非共价相互作用的自组装过程构建的,但这种独特的特性会导致其管状结构的固有不稳定性。在此,我们报告了一种简单的“螺旋到管”策略,从具有手性酰胺侧链的易于获得的聚(间亚苯基二乙炔)(poly-PDE)构建稳健的共价 ONT,该侧链可以通过氢-结合相互作用。螺旋折叠的聚 PDE 随后在纵向排列的 1 处发生光诱导交联,整个螺旋中的 3-丁二炔部分在溶液和固相中形成共价管 (ONT)。poly-PDEs 和共价 ONTs 的结构通过光谱分析、衍射分析和显微分析表征。我们设想这种简单而强大的“螺旋到管”策略将通过将功能部分引入单体中来产生一系列基于 ONT 的材料。
Remarkable Enhancement of Stability and Helix-sense Excess of Oligo(phenylene ethynylene) Foldamers Assisted by Linking with Achiral (Metallo)salen Tethers and Their Application to Asymmetric Catalysis
作者:Naoki Ousaka、Tomoko Yamaguchi、Eiji Yashima
DOI:10.1246/cl.131168
日期:2014.4.5
Two foldamer strands, which possess chiral amide pendants but imperfect helical handedness, were linked by an achiral (metallo)salen tether, leading to a remarkable enhancement of helical stability and helix-sense excess as a result of the intramolecular hydrogen-bond networks along the entire dimeric foldamer strand; the MnIII salen complexes catalyzed an asymmetric epoxidation reaction.
Highly efficient stabilisation of meta-ethynylpyridine polymers with amide side chains in water by coordination of rare-earth metals
作者:Hiroki Makida、Hajime Abe、Masahiko Inouye
DOI:10.1039/c4ob02129k
日期:——
An amphiphilic meta-ethynylpyridine polymer with chiral amide side chains coordinated with rare-earth metal salts, especially strongly with Sc(iii), to stabilise its helical structure with CD enhancement.