Transition Metal Clusters as Single-Molecule Magnets

技术总结拟议的研究，由DMR固态和材料化学计划的支持，是在单分子磁体（SMM）领域。SMM是可以用作纳米级磁体的分子，它们将分子化学的所有优点带到纳米磁性领域，包括溶解度，结晶度，单分散性和有机配体的外壳，其修饰可以微调许多这些性质和其他性质，如氧化还原电位。这些工作将推动该领域沿着沿着多个前沿主要是新的方向向前发展，包括：（i）通过适当设计的桥连配体将多个SMM共价连接成超分子聚集体，这些超分子聚集体仍然是分子的，并且表现出弱的SMM间交换相互作用，其引入量子效应，例如组成SMM单元的叠加态和纠缠;（ii）使用光致变色有机桥接配体以允许开发用于控制超分子聚集体中的单独SMM之间的相互作用的光开关ON和OFF的方法，从而开关ON和OFF导致它们的量子纠缠和叠加态的量子力学耦合;这是将SMM用作量子比特的先决条件（iii）利用后来的镧系元素离子的高磁各向异性，合成具有比目前可用的更高的操作温度的新的混合金属3d-4f SMM;以及（iv）涉及合成“分子多铁性”的新方向的开始，所述分子多铁性在结构上类似于式MMnO 3和MFeO 3的混合金属锰氧化物和铁氧体多铁性氧化物（M =镧系元素或主族金属）;这些三元氧化物具有磁性和铁电性顺序，并且目标是开发获得也表现出这两种类型性质的分子的方法。一些新的合成方法，一些涉及更高的能量条件下使用微波反应器，将被开发来实现这些目标。非技术总结磁性材料是一个数十亿美元的年度产业在美国。目前包含磁体的装置的小型化趋势使得越来越小的磁体的开发变得至关重要。拟议的研究是在单分子磁体（SMM）领域;这些是作为纳米级磁体的单个分子，比传统磁性材料小得多。拟议的研究有多个目标，包括改善已知SMM的特性，开发将其中两个或更多个连接在一起的方法，以引入某些对SMM在量子计算等新技术中的潜在用途至关重要的效应，并使SMM也具有第二个重要特性，使它们能够用于材料科学的其他领域。私家侦探他的研究小组也将积极参与许多外展、教育和国际活动，以最大限度地扩大他的研究项目的广泛影响。他将支持规划和执行一年一度的化学日在盖恩斯维尔，佛罗里达州的商场，针对K-12学生，他们的老师和家长，以及当地社区和媒体;他将每年举办一个佛罗里达高中学生夏季研究根据佛罗里达大学？的学生科学培训计划，他将继续组织年度佛罗里达无机和材料研讨会学生会议的13个佛罗里达高等教育机构跨越博士授予大学，本科学院和社区学院;他将共同组织两个两年一度的国际研讨会，在分子和纳米级磁性研讨会（2014年）的当前趋势，和北美-希腊-塞浦路斯顺磁材料研讨会（2013年，2015年），这两个都强调学生和博士后的口头报告。私家侦探他还将继续与几个国家和国际团体合作，向物理学家提供研究样品，用于研究量子和其他性质，并使用合成化学家无法使用的技术研究合成化学家发送的化合物。

TECHNICAL SUMMARYThe proposed research, supported by the DMR Solid State and Materials Chemistry program, is in the field of single-molecule magnets (SMMs). SMMs are molecules that can function as nanoscale magnets, and they bring all the advantages of molecular chemistry to the field of nanomagnetism, including solubility, crystallinity, monodispersity, and a shell of organic ligands whose modification can fine-tune many of these properties and others such as redox potentials. The proposed work will push the area forward along multiple fronts in mainly new directions, including: (i) the covalent linkage of multiple SMMs by suitably designed bridging ligands into supramolecular aggregates that are still molecular and exhibit weak inter-SMM exchange interactions that introduce quantum effects such as superposition states and entanglement of the constituent SMM units; (ii) the use of photochromic organic-bridging ligands to allow development of methods for controlled photo-switching ON and OFF of the interactions between separate SMMs in supramolecular aggregates, thus switching ON and OFF the quantum mechanical coupling that results in their quantum entanglement and superposition states; this is an ability that is a pre-requisite for the use of SMMs as qubits (quantum bits) in quantum computing and related specialized applications; (iii) the synthesis of new mixed-metal 3d-4f SMMs with higher operating temperatures than are currently available, taking advantage of the high magnetoanisotropy of the later lanthanide ions; and (iv) the initiation of a novel direction involving the synthesis of 'molecular multiferroics' that are structurally analogous to mixed-metal manganite and ferrite multiferroic oxides of formula MMnO3 and MFeO3 (M = a lanthanide or main-group metal); these ternary oxides possess both magnetic and ferroelectric order, and the objective is to develop methods to access molecules that also exhibit both of these types of properties. A number of new synthetic methodologies, some involving higher-energy conditions using microwave reactors, will be developed to accomplish these objectives.NON-TECHNICAL SUMMARYMagnetic materials are a multi-billion dollar annual industry in the USA. Current trends in miniaturization of devices containing magnets have made the development of smaller and smaller magnets essential. The proposed research is in the area of single-molecule magnets (SMMs); these are individual molecules that function as nanoscale magnets that are much smaller than those of traditional magnetic materials. The proposed research has multiple objectives, including improving the properties of known SMMs, developing methods to link two or more of them together to introduce certain effects crucial to the potential use of SMMs in new technologies such as quantum computing, and making SMMs that also possess a second important property that will allow them to be employed in other areas of materials science. The P.I. and his group will also be active in many outreach, education and international activities designed to maximize the broader impacts of his research program. He will support the planning and execution of the annual Chemistry Day at the Mall in Gainesville, FL, targeted at K-12 students, their teachers and parents, and the local community and media; he will host each year a Florida high-school student for summer research under the University of Florida?s Student Science Training Program; he will continue to organize the annual Florida Inorganic and Materials Symposium student meetings of 13 Florida higher education institutions spanning PhD granting universities, undergraduate colleges, and community colleges; and he will co-organize two biennial international workshops, the Current Trends in Molecular and Nanoscale Magnetism workshop (2014), and the North America-Greece-Cyprus Workshop on Paramagnetic Materials (2013, 2015), both of which emphasize oral presentations from students and postdoctorals. The P.I. will also continue collaborating with several national and international groups, providing research samples to physicists for study of quantum and other properties, and studying compounds sent by synthetic chemists using techniques not available to them.