Enforced Folding of Oligo(phenylene ethynylenes)

非天然的低聚物和聚合物组成的苯环连接乙炔基（苯乙炔）被设计成折叠成多孔的螺旋结构，由本地化的分子内氢键。具有足够长的主链的寡聚体自身折叠，导致左手和右手螺旋。这种基于主链的螺旋编程提供稳定的螺旋结构，而不管决定外表面性质的侧基的结构变化。由此产生的螺旋的内部由芳香族氢原子排列，使得这些管状空腔相当疏水。螺旋的内径是可调节的（8埃至40埃或更大），提供了获得具有可调节内腔的新型非自然折叠纳米管的途径。此外，这些非天然的折叠体具有螺旋和不饱和的骨架，这些特征可能赋予不寻常和有用的物理和化学性质。纳米空腔和通道在催化、分离、纳米器件（传感器、流体学等）、光学器件（光学器件）等方面有着广泛的应用前景。用于构建更大结构的纳米支架，以及其他纳米多孔材料的设计。在有机和高分子化学项目的支持下，州立大学纽约-布法罗分校化学系龚兵教授和内布拉斯加大学-林肯分校化学系曾晓成教授正在研究设计用于选择性和有效地折叠成螺旋结构的碳基分子的合成和性质。这些螺旋结构包含可调节尺寸和功能的纳米通道，允许调节其特性及其与其他分子的相互作用。这些研究还提供了有关其他大分子折叠的基本信息，包括自然和非自然的，进行这些跨学科研究的学生获得有机合成，生物有机和超分子有机化学以及理论化学的技能。

Unnatural oligomers and polymers consisting of benzene rings linked by ethynyl groups (phenyleneethynylenes) are designed to fold into porous helical structures, enforced by localized intramolecular hydrogen bonds. An oligomer with a sufficiently long backbone folds back on itself, leading to left- and right-handed helices. Such a backbone-based helical programming affords stable helical structures regardless of structural variation of the side groups that determine the outside surface properties. The interior of the resulting helices is lined by aromatic hydrogen atoms, making these tubular cavities rather hydrophobic. The internal diameters of the helices are adjustable (8 angstrom to 40 angstrom and larger), providing access to novel unnatural folding nanotubes with adjustable interior cavities. Furthermore, these unnatural foldamers have backbones that are both helical and unsaturated, features that may endow unusual and useful physical and chemical properties. The design and synthesis of helices with superhydrophobic (fluorinated) or amphiphilic interior cavities, resolution of enantiomers, and induction of helical twist sense by chiral side chains and chiral solvents are also addressed.Nanosized cavities and channels have numerous potential applications in catalysis, separations, nanodevices (sensors, fluidics, etc.), nanoscaffolds for building larger structures, and design of other nanoporous materials. With the support of the Organic and Macromolecular Chemistry Program, Professor Bing Gong, of the Department of Chemistry at the State University of New York - Buffalo and Professor Xiao Cheng Zeng, of the Department of Chemistry at the University of Nebraska - Lincoln, are studying the synthesis and properties of carbon-based molecules designed to fold selectively and efficiently into helical structures. These helical structures contain nanosized channels of adjustable size and functionality, allowing tuning of their properties and their interactions with other molecules. These studies also provide fundamental information about the folding of other large molecules, both natural and unnatural, Students carrying out these interdisciplinary studies gain skills in organic synthesis, bioorganic and supramolecular organic chemistry, and theoretical chemistry.