Low-Coordinate Building Blocks for Cyanide-Based Single-Molecule Magnets

化学结构、动力学和机制项目支持密苏里大学圣彼得堡分校的斯蒂芬·霍姆斯教授。Louis等人研究了作为过渡金属取代、连接和辅助配体、配位环境和自旋基态简并的过渡金属取代、连接和辅助配体的函数的模块构建块及其多核衍生物的磁性行为的差异。将探索了解单离子磁各向异性如何转化为一系列结构相关的双核和三核配合物表现出的磁性的努力。几个含有顺磁中心和轨道简并基态的3-和4-配位分子构件将被构建；空间要求高的配体将加强这种几何结构，并允许有效的自旋-轨道耦合相互作用。这项工作的目标是阐明单离子磁相互作用如何有助于形成具有异常大的零场分裂的自旋基态的多核复合体的起源。几种含有线性M-X-M‘桥的双金属和三金属单分子磁性络合物(SMM)，其中X=氰化物和1，4-丁二亚甲基，将使用专门设计的前体络合物进行探索。我们将绘制结构-性质关系，并用来完善我们对轨道简并和各向异性自旋中心如何设计和使用来构建SMM的理解。这项拟议的研究将影响将可溶性过渡金属络合物用作一系列信息存储技术中的可切换组件的努力。拟议的国内/国际合作和交流将使参与的学生能够发展全球科学观点，建立潜在的终身合作关系，并提供获得国内机构目前无法获得的互补技能和专业知识的机会。大圣路易斯地区内众多本科生、ACS种子和地区明星(作为研究科学家的学生和教师)学生和高中教师的指导将继续是研究工作不可或缺的一部分。

The Chemical Structure, Dynamics and Mechanisms Program supports Professor Stephen Holmes of the University of Missouri-St. Louis to investigate differences in magnetic behavior for modular building blocks and their polynuclear derivatives, as a function of transition metal substitution, linking and ancillary ligands, coordination environment, and spin ground state degeneracy. Efforts to understand how single-ion magnetic anisotropy translates into magnetic properties exhibited by a series of structurally related bi- and trinuclear complexes will be explored. Several 3- and 4-coordinate molecular building blocks containing paramagnetic centers with orbitally degenerate spin ground states will be constructed; sterically demanding ligands will enforce this geometry and allow for efficient spin-orbit coupling interactions. Elucidating origins of how single-ion magnetic interactions assist in the formation of polynuclear complexes that spin ground states with exceptionally large zero-field splittings are the goals of this effort. Several bi- and trimetallic single-molecule magnetic complexes (SMMs) containing linear M-X-M´ bridges, where X = cyanide and 1,4-butadiynylide, will be explored using purposefully designed precursor complexes. Structure-property relationships will be drawn and used to refine our understanding of how orbitally degenerate and anisotropic spin centers can be designed and used to construct SMMs. The proposed research will impact efforts to use soluble transition metal complexes as switchable components in a range of information storage technologies. Proposed domestic/international collaborations and exchanges will allow participating students to develop a global perspective of science, establish potentially life-long collaborations, and afford access to complementary skills and expertise currently unavailable at their home institutions. Mentorship of numerous undergraduate, ACS SEED, and regional STARS (Students and Teachers as Research Scientists) students and high school teachers within the greater St. Louis region will continue to be integral to research efforts.