Unusual Structure and Bonding in Strained Aromatic Molecules

应变芳香分子中的异常结构和键合

• 批准号: 9106903
• 负责人: Robert Pascal
• 金额: $ 21万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-05-01 至 1994-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9106903&HistoricalAwards=false
• 关键词: Unusual; Structure; Bonding; Strained; Aromatic

The synthesis and properties of molecules in which two relatively unreactive functional groups are forced into close proximity to each other will be studied. Particular emphasis will be placed on in-cyclophanes bearing phosphine lone-pair electrons brought into close proximity with aromatic rings. Other electron-rich groups, such as olefins, amines, phosphine oxides, and silyl fluorides will also be examined. By balancing the forces due to intramolecular strain in these compounds with the nucleophilicity or electrophilicity of the aromatic ring, it may be possible to obtain structures in which there is partial bonding between the groups in question. Such structures may serve as models for transition state structures in ordinary aromatic reactions. A second part of the project will involve the synthesis and study of the physical properties of fullerene fragments. Each of these fragments will be a different segment of buckminsterfullerene (spherical C60). %%% This grant from the Organic Dynamics Program supports the continuing work of Professor Robert Pascal at Princeton University. the main focus of the project is the synthesis and study of highly strained organic molecules, i.e., molecules in which some atoms are forced by steric constraints to occupy positions which lead to unnatural interactions with other atoms and to unusual bond distances and angles. Of particular interest are the structure and reactivity of molecules in which two relatively unreactive functional groups are forced to be very close together. It is expected that the enforced proximity will lead to unusual reactivity for the groups involved,and to unusual physical properties as well. In another part of this project, fragments of a recently discovered spherical C60 allotrope of carbon (other allotropes of carbon are diamond and graphite) will be prepared in order to understand how C60 may be formed from carbon fragments.

将研究两个相对不反应的官能团相互接近的分子的合成和特性。特别重点将放在带有磷酸唯一的唯一电子电子的循环内，与芳香环接近。还将研究其他富含电子的基团，例如烯烃，胺，磷酸氧化物和甲硅烷基氟化物。通过在这些化合物中由于分子内应变而与芳环的亲核性或亲电性平衡，可以获得所讨论组之间存在部分键合的结构。这种结构可以用作普通芳族反应中过渡状态结构的模型。该项目的第二部分将涉及富勒烯碎片的物理特性的合成和研究。这些片段中的每一个都将是Buckminsterfullerene的不同段（球形C60）。 %% %%来自有机动力学计划的这笔赠款支持普林斯顿大学罗伯特·帕斯卡（Robert Pascal）教授的持续工作。该项目的主要重点是对高度应变的有机分子的综合和研究，即某些原子受空间约束强迫的分子，以占据位置，从而导致与其他原子和异常键的距离和角度不自然的相互作用。特别令人感兴趣的是分子的结构和反应性，其中两个相对不反应的官能团被迫非常接近。预计强化的接近度将导致相关组的异常反应性，并且还会导致异常的物理特性。在该项目的另一部分中，将准备一个最近发现的碳球形C60同素异素（其他同质量是钻石和石墨）的片段，以了解如何从碳碎片中形成C60。