SGER: Synthesis and Properties of Edge-charged Molecules

该项目将测试一个假设，即由两个或多个线性融合的γ -吡啶酮或γ -吡啶酮组成的平面分子将表现出电荷离域，从而导致沿分子相对边缘的高度电荷。随着融合的吡咯酮和吡啶酮数量的增加，与这些分子结构相关的芳香性会增加，从而导致电荷离域。可以设想两种结构类型；一种是分子的每条边都带电荷，即一条边带正电，另一条边带负电，另一条边带交替电荷。线性融合的γ -吡咯酮和γ -吡咯酮将由多达四个单体单元合成，并将研究每个系统的性质。研究将包括(a)偶极矩测量（一种阵列应该有非常大的偶极矩，另一种阵列基本上为零），(b) x射线晶体学分析，以评估键长随系统芳香性增加而变化的程度，(c)核磁共振测量，以评估与这种芳香性相关的抗磁性各向异性，以及(d)设计用于检查这些结构带电边缘的金属离子配位的实验。这些系统的宏观组合将由边缘到边缘的静电吸引，pi堆叠和其他分子间力引起，并将研究可能用于开发新材料的固态特性。有了这个奖项，有机和大分子化学项目支持俄勒冈州立大学化学系的詹姆斯·d·怀特教授的研究。怀特教授的研究方向是发现新的合成方法，并将其应用于合成包括天然和非天然物质在内的新结构。这些努力将对用于电子和制药工业等各种环境的新型有机材料的开发产生影响。

This project will test a hypothesis that planar molecules consisting of two or more linearly fused gamma-pyrones or gamma-pyridones will exhibit charge delocalization that results in a high degree of charge along opposite edges of the molecule. Charge delocalization will result from increasing aromaticity associated with these molecular structures as the number of fused pyrones and pyridones increases. Two structural types can be envisioned; one has charges along each edge of the molecule of the same sign, i.e. one edge is positively charged and the opposite edge is negatively charged and the other array has alternating charges along each edge. Linearly fused gamma-pyrones and gamma-pyridones will be synthesized with up to four monomer units and the properties of each system will be studied. The studies will include (a) dipole moment measurements (one array type should have a very large dipole moment, the other essentially zero), (b) X-ray crystallographic analysis to assess the degree to which bond lengths change with increasing aromaticity of the system, (c) nuclear magnetic resonance measurements to evaluate diamagnetic anisotropy associated with this aromaticity, and (d) experiments designed to examine metal ion coordination along the charged edges of these structures. Macroscopic assemblages of these systems resulting from edge-to-edge electrostatic attraction, pi-stacking and other intermolecular forces will be studied, and solid state properties potentially useful for the development of new materials will be investigated. With this award, the Organic and Macromolecular Chemistry Program is supporting the research of Professor James D. White of the Department of Chemistry at Oregon State University. Professor White's research is directed towards the discovery of new synthetic methods and their application to the synthesis of novel structures including both natural and non-natural substances. These effort will have an impact on the development of new organic materials for use in a variety of settings such as the electronics and pharmaceutical industries.