Spincrossover complexes with long-lived excited high spin states stabilized by changing coordination number

通过改变配位数来稳定具有长寿命激发高自旋态的自旋交叉复合物

• 批准号: 253056146
• 负责人: Dr. Holm Petzold
• 金额: --
• 依托单位: Professur Anorganische Chemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/253056146?language=en
• 关键词: Spincrossover; complexes; long; lived; excited

In line with the ongoing miniaturization in the electronic industry, the design of molecular switches and data storage devices is going to become a key technology. Spincrossover complexes are able to serve as such devices. Spincrossover complexes can have two distinct spin states (high spin state and low spin state) which are addressable with light with exceptional high quantum yields. Unfortunately, for many possible applications the activation energy for the thermally activated conversion between the two states is far too low. In this project, this problem is going to be attacked by a change in the coordination number from six (low spin state) to seven (high spin state). The design starts with Fe2+ complexes employing strong NHC and polypyridyl ligands that are found in a very stable low spin state. The low spin complexes are tuned to spincrossover complexes by introduction of a sterically active substituent that at the same time includes a seventh donor. The magnetic properties are going to be investigated by variable temperature UV/Vis spectroscopy, proton NMR spectroscopy, as well as laser flash photolysis and measurement of the magnetic properties on a SQUID. This to date only rarely used principle of N6/N7 coordination change should allow the observation of long lived excited spin states.

随着电子工业不断小型化，分子开关和数据存储器件的设计将成为一项关键技术。自旋交叉复合物能够充当这样的装置。自旋交叉复合物可以具有两种不同的自旋态（高自旋态和低自旋态），可以用光寻址并具有极高的量子产率。不幸的是，对于许多可能的应用来说，两种状态之间的热激活转换的激活能太低。在这个项目中，这个问题将通过将配位数从六（低自旋状态）更改为七（高自旋状态）来解决。该设计从 Fe2+ 配合物开始，采用强 NHC 和多吡啶配体，这些配体处于非常稳定的低自旋状态。通过引入同时包含第七个供体的空间活性取代基，将低自旋配合物调整为自旋交叉配合物。将通过变温紫外/可见光谱、质子核磁共振光谱以及激光闪光光解和 SQUID 磁性测量来研究磁性。迄今为止，这种 N6/N7 配位变化的原理很少使用，应该可以观察到长期存在的激发自旋态。

项目成果

Spin state variability in Fe2+ complexes of substituted (2-(pyridin-2-yl)-1,10-phenanthroline) ligands as versatile terpyridine analogues.

• DOI: 10.1039/c7dt00422b
• 发表时间: 2017-05
• 期刊: Dalton transactions
• 影响因子: 4
• 作者: H. Petzold;P. Djomgoue;G. Hörner;Silvio Heider;C. Lochenie;Birgit Weber;T. Rüffer;Dieter Schaarschmidt

(1)H NMR spectroscopic elucidation in solution of the kinetics and thermodynamics of spin crossover for an exceptionally robust Fe(2+) complex.

(1)H NMR 光谱阐明了异常坚固的 Fe(2 ) 配合物的自旋交叉动力学和热力学

• DOI: 10.1039/c6dt01895e
• 发表时间: 2017
• 期刊: Dalton transactions
• 影响因子: 4
• 作者: H. Petzold;P. Djomgoue;G. Hörner;S. Heider;C. Lochenie;B. Weber;T. Rüffer;D. Schaarschmidt
• 通讯作者: D. Schaarschmidt