Development of Stable Neutral Radicals Having an Unconventional Spin-Delocalized Nature

具有非常规自旋离域性质的稳定中性自由基的发展

基本信息

批准号：
15087202
负责人：
MORITA Yasushi
金额：
$ 18.43万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2006
项目状态：
已结题

项目摘要

Organic open-shell molecules, widely recognized as short-lived reactive intermediates, have recently drawn attention as building blocks for new molecule-based functional materials, since various stabilization techniques have been developed. In order to strengthen the basis of this research field, it is crucial to establish novel design criteria and synthetic methodologies of open-shell molecular systems with structurally and electronically salient features. In this study, we have synthesized and characterized new organic open-shell systems having topologically-controlled and extremely delocalized spin-density distribution natures, demonstrating exotic electronic features originating from these electronic spin structures. (1) realization of novel thermochromism based on dynamic electron-spin behavior : We have experimentally determined chemical structure of Ti-dimer formed in a solution state at low temperature, revealing a new C-C bond with 12-center-2-electron nature. Furthermore, aromaticity of a radical aggregate was first proposed in our study. (2) realization of the switching system in terms of spin-center transfer of purely organic open-shell system : We have prepared TTF-linked 6-oxophenalenoxyl neutral radical system, and created solvent-and temperature-controlled complete spin-switching system based on intramolecular electron transfer. (3) The delocalized singlet biradical hydrocarbons were first synthesized, isolated, and characterized, showing the highest room-temperature electric conductivity as single-component hydrocarbon, and exceptionally large two-photon absorption cross sections for pure hydrocarbon with no electron-donor or-acceptor substituents.

由于已经开发了各种稳定技术，因此有机开放壳分子被广泛认为是短寿命的反应性中间体，最近引起了人们对基于新分子的功能材料的基础的关注。为了加强该研究领域的基础，建立具有结构和电子上显着特征的开放式分子系统的新型设计标准和合成方法至关重要。在这项研究中，我们合成并表征了新的有机开放式壳系统，具有拓扑控制且极其离域的旋转密度分布表明，展示了源自这些电子自旋结构的异国情调电子特征。（1）基于动态电子旋转行为的新型热色素的实现：我们已经在低温下以溶液状态形成的TI-二聚体的实验确定的化学结构，揭示了具有12中心2电子性质的新的C-C键。此外，在我们的研究中首先提出了根部骨料的芳香性。（2）从纯有机开放式壳系统的自旋中心转移方面实现开关系统：我们已经准备了基于溶剂和温度控制的完整的自旋开关系统，基于内部分子电子转移。（3）首先合成，隔离和表征的离域单线Biradical碳氢化合物，显示出最高的室温电导率，作为单一组分的烃类，以及对于纯碳氢化合物的特殊较大的两光子吸收横截面，没有电子或无电子或actaccepptor的纯碳酸盐。