权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Spin Alignment in Model Molecules for Organic Ferrimagnets as Studied by ENDOR/TRIPLE Spectroscopy

通过 ENDOR/TRIPLE 光谱研究有机亚铁磁体模型分子中的自旋排列

基本信息

批准号：
02453014
负责人：
ITOH Koichi
金额：
$ 3.01万
依托单位：
Osaka City University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1992
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-02453014/
关键词：
Organic ferrimagnets Unusually large negative spin polarization Organic molecular based magnetism ENDOR TRIPLE pi Topoology Spin multiplet-multiplet interaction Hetero-spin systems Spin chemistry 有機フェリ磁性複合型高スピン分子電子核ー核三重共鳴スピン密度分布

项目摘要

Organic molecular based magnetism has been the focus of current topics in many fields of both pure and applied sciences. It is of crucial importance to substantiate the possible occurrence of various types of purely organic magnetism, particularly purely organic ferrimangetism which is defined as antiferromagnetically coupled organic hetero-spin assemblages with coherence length of long range.This program deals with the topologically spin-controlled molecular design and spin structure of the first organic hetero-spin system, 4-(diphenylmethylene)-4'-(m-phenylenebis (phenylmethylene)-ether 1, in which non-identical spins (S_i=1 and S_j=2) couple antiferromagnetically via an ether bridge in the ground state. The hetero spin system is a model for purely organic ferrimagnets via through-bond approaches, in which the underlining magnetic coupling is superexchange interaction via the bridge. The concept of the molecular design under study is associated with a counterpart of crystalline ferrimagnets via through-space approaches commonly exploited in magnetic materials. The single-crystal ENDOR spectroscopy has been applied to 1, featuring an unusually large negative spin polarization in the spin density distribution for the ground state (S=1). The finding discloses a physical insight into organic ferrimagnetism. The unusual negative spin polarization strictly arises from a salient feature of organic hetero-spin systems in the electronic ground state, directly showing that one molecular spin moiety with S_i (S_j=1) is inverted against the another with an inequivalent spin S_j (S_j=2) in antiferromagnetically coupled hetero-spin systems. The spin-inversion is responsible for such an unusually large negative spin polarization that chemistry so far has never expected. It is referred to a new aspect of negative spin polarization in chemistry.

有机分子磁性是当前理论科学和应用科学研究的热点。这对证实各种类型的纯有机磁性，特别是纯有机亚铁锰磁性的可能性至关重要，它被定义为具有长范围相干长度的反铁磁耦合的有机异自旋集合体。本程序涉及第一个有机异自旋系统的拓扑自旋控制的分子设计和自旋结构，4-（二苯基亚甲基）-4 '-（间亚苯基）双（苯基亚甲基）醚1，其中不同自旋（Si =1和Si =2）在基态通过醚桥反铁磁耦合。异质自旋系统是一个通过键方法的纯有机亚铁磁体模型，其中底层的磁耦合是通过桥的超交换相互作用。正在研究的分子设计的概念是与对应的晶体亚铁磁体通过通常利用在磁性材料中的通过空间的方法。单晶ENDOR光谱已被应用到1，具有异常大的负自旋极化的自旋密度分布的基态（S=1）。这一发现揭示了有机亚铁磁性的物理见解。这种反常的负自旋极化严格地来源于有机异自旋体系在电子基态的一个显著特征，它直接表明在反铁磁耦合的异自旋体系中，自旋为Si（Si =1）的分子与自旋为Si（Si =2）的分子相互反转。自旋反转导致了如此大的负自旋极化，这是迄今为止化学界从未预料到的。这是负自旋极化在化学中的一个新的方面。