Single-molecule magnetism in lanthanide organometallics

镧系有机金属中的单分子磁性

基本信息

批准号：
EP/K008722/1
负责人：
Richard Layfield
金额：
$ 44.15万
依托单位：
University of Manchester
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2013
资助国家：
英国
起止时间：
2013 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FK008722%2F1
关键词：
Single molecule magnetism lanthanide organometallics

项目摘要

Molecules that have a magnetic memory are called single-molecule magnets (SMMs). In terms of their size and composition, SMMs have dimensions of a few nanometres and they consist of one or more metal atoms bonded to a group of non-metal atoms called a ligand. The interactions between neighbouring molecules are very weak, meaning that the magnetic properties of an SMM genuinely arise from within individual molecules.In stark contrast to SMMs, traditional 'bar' magnets used in everyday appliances are purely inorganic materials such as metal oxides or simply magnetic elements. A particularly important example of their application is in computer hard disk drives. In terms of their size and composition, rather than consisting of molecules traditional magnets feature much larger magnetic domains.Because one of the main differences between SMMs and traditional magnets relates to size, it is possible that SMMs represent the ultimate size limit for magnetic information storage. The properties of SMMs may one day allow them to be developed for use in quantum computers. A problem with SMMs is, however, that their magnetic memories function at temperatures of about -250oC, which can only be reached by cooling with liquid helium and is therefore impractical. Furthermore, the mechanisms by which SMMs relax their magnetization (i.e. the magnetic information is lost or 'wiped') are not clear, but it is likely that gaining an understanding of these processes will lead to enhanced performance at higher temperatures.We propose a new family of SMMs based on the lanthanide elements (Ln-SMMs). The lanthanides offer considerable potential for developing SMMs because these elements have particularly appealing magnetic properties. Ultimately, our Ln-SMMs will have magnetic memory effects observable above -196oC, which will be a major advance because this temperature can be reached by cooling with liquid nitrogen, a cryogen that is much cheaper than liquid helium, and easier to use.We will achieve our aims by using a molecular design tool available to us as synthetic chemists: we can make significant changes to the ways in which our ligands interact with our choice of lanthanide. This is important because the non-metal atoms used to interact with the lanthanides, and the symmetry with which the ligands are arranged around the lanthanides, allow us to influence the magnetism.A unique aspect of our approach to the design of Ln-SMMs is that our synthetic method gives access to an extremely broad range of chemical environments. Existing, conventional Ln-SMMs are almost entirely limited to ligands in which oxygen or nitrogen interacts with the lanthanide, however we can influence the magnetism using carbon, oxygen, sulphur, selenium, tellurium, nitrogen, phosphorus, arsenic, antimony or the halogens.By understanding the ways in which the different chemical environments influence the molecular magnetism we will be able to identify the optimum conditions for producing Ln-SMMs that function at unprecedentedly high temperatures.

具有磁性记忆的分子称为单分子磁铁（SMM）。就其大小和组成而言，SMM具有几种纳米的尺寸，它们由一个或多个金属原子组成，该金属原子粘合到一组称为配体的非金属原子。相邻分子之间的相互作用非常弱，这意味着SMM的磁性真正来自单个分子内部。在与SMM的形成鲜明的对比中，在SMM的形成鲜明的对比中，在日常设备中使用的传统“ bar”磁铁是纯粹的无机材料，例如金属氧化物或简单的磁性元件。他们应用的一个特别重要的例子是在计算机硬盘驱动器中。就其大小和成分而言，而不是由分子组成的传统磁体具有更大的磁性域。因为SMM和传统磁体之间的主要区别之一与尺寸有关，因此SMM可能代表磁性信息存储的最终尺寸限制。 SMM的属性可能有一天可以使它们在量子计算机中使用。但是，SMM的一个问题是它们的磁性记忆在约-250oC的温度下起作用，只能通过液态氦气冷却，因此不切实际。此外，SMM放松其磁化的机制（即磁性信息丢失或“擦拭”）尚不清楚，但很可能获得对这些过程的了解会在较高的温度下提高性能。我们建议基于Lanthanide元素（LN-SMMS）的新型SMMS家族（LN-SMM）。灯笼为开发SMM提供了巨大的潜力，因为这些元素具有特别吸引人的磁性特性。归根结底，我们的LN -SMM将在-196oC上观察到的磁回忆效应，这将是一个重大进步，因为可以通过使用液氮冷却来达到该温度，该温度比液体氦更便宜得多，并且更易于使用，并且我们将通过使用与合成化学家相互作用的分子设计工具来实现我们的目标：我们可以与我们的合成化学效果进行重大更改。这很重要，因为非金属原子用于与灯笼相互作用，以及配体在灯笼周围排列的对称性，使我们能够影响磁性。我们的LN-SMMS设计方法的独特方面是，我们的合成方法可以访问非常宽的化学环境。现有的常规LN-SMM几乎完全限于氧气或氮与灯笼的配体相互作用的配体，但是我们可以使用碳，氧气，硫，硫酸，硒，三核，硝酸盐，氮，氮，磷，磷，砷，砷，砷，抗孔或卤素的方式来影响磁性，从而识别摩尔的摩擦，我们可以识别摩擦量，从而识别摩尔的摩擦，我们可以识别各种化学量，从而确定了摩擦的方式。产生在前所未有的高温下发挥作用的LN-SMM的条件。

项目成果

期刊论文数量（8）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Iron- and Cobalt-Catalyzed Synthesis of Carbene Phosphinidenes.

DOI：
10.1002/anie.201508303
发表时间：
2016-01-26
期刊：
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
影响因子：
16.6
作者：
Pal, Kuntal;Hemming, Oliver B.;Day, Benjamin M.;Pugh, Thomas;Evans, David J.;Layfield, Richard A.
通讯作者：
Layfield, Richard A.

Reactivity of three-coordinate iron-NHC complexes towards phenylselenol and lithium phenylselenide.

DOI：
10.1039/c3dt53203h
发表时间：
2014-02
期刊：
Dalton transactions
影响因子：
4
作者：
Thomas Pugh;R. Layfield
通讯作者：
Thomas Pugh;R. Layfield

Influencing the properties of dysprosium single-molecule magnets with phosphorus donor ligands.

DOI：
10.1038/ncomms8492
发表时间：
2015-07-01
期刊：
Nature communications
影响因子：
16.6
作者：
Pugh T;Tuna F;Ungur L;Collison D;McInnes EJ;Chibotaru LF;Layfield RA
通讯作者：
Layfield RA

Strong Exchange Coupling in a Trimetallic Radical-Bridged Cobalt(II)-Hexaazatrinaphthylene Complex

三金属自由基桥联钴(II)-六氮杂萘配合物中的强交换耦合

DOI：
10.1002/ange.201600694
发表时间：
2016
期刊：
Angewandte Chemie
影响因子：
0
作者：
Moilanen J
通讯作者：
Moilanen J

Strong Exchange Coupling in a Trimetallic Radical-Bridged Cobalt(II)-Hexaazatrinaphthylene Complex.

DOI：
10.1002/anie.201600694
发表时间：
2016-04-25
期刊：
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
影响因子：
16.6
作者：
Moilanen, Jani O.;Chilton, Nicholas F.;Day, Benjamin M.;Pugh, Thomas;Layfield, Richard A.
通讯作者：
Layfield, Richard A.