Single Molecule Magnets

这个无机、生物无机和有机金属化学项目的奖项支持David N. Hendrickson教授更好地控制单分子磁体（SMMs）量子特性的研究。研究了室温下化学合成的结构明确的单分散纳米磁体的量子隧道效应。smm将通过灵敏的电子顺磁共振方法、核磁共振（NMR）和磁强计技术进行表征。本研究的目标包括：1)合成新的smm，以调节控制磁化动力学性质的各种因素；(2)研究磁化共振量子隧穿（QTM）机制；(3)研究分子间磁交换相互作用对QTM的影响；(4)研究自旋较大的分子（如S = 13）到自旋较小的分子（如S = 4）的性质变化；(5)详细考察了半整数自旋smm（如S = 9/2、13/2等）的自旋宇称效应；(6)制备并表征具有输运性质的新型smm；(7)将smm贴合到功能化的金属表面或聚合物上；(8)开发具有光子可及性的smm；(9)制备掺杂S = 0反铁磁环和多核配合物的非补偿自旋smm；（10）发现为什么某些Mn12 smm具有磁化隧道效应，其活化能为其他Mn12 smm的一半。单分子磁体为纳米级数据存储和其他应用提供了潜力。本研究旨在开发新型单分子磁体，并研究它们所呈现的新量子效应。合作涉及三个不同国家的物理小组和几个化学小组，这将加强研究生和本科生不同群体的研究训练。

This award in the Inorganic, Bioinorganic and Organometallic Chemistry program supports research by Professor David N. Hendrickson to better control the quantum properties of single-molecule magnets (SMMs). The quantum tunneling of magnetization in monodisperse nanomagnets with well-defined structures prepared by chemical synthesis in solution at ambient temperatures will be investigated. The SMMs will be characterized by sensitive electron paramagnetic resonance methods, nuclear magnetic resonance (NMR) and magnetometry techniques. Goals of this research include: 1) synthesizing new SMMs in order to adjust the various factors controlling the nature of magnetization dynamics; (2) investigating the mechanism for the resonant quantum tunneling of magnetization (QTM); (3) pursuing the influence of intermolecular magnetic exchange interactions on QTM; (4) studying how the properties of SMMs change going from a molecule with a relatively large spin such as S = 13 to one with a small spin such as S = 4; (5) examining in detail spin parity effects exhibited by half-integer (e.g., S = 9/2, 13/2, etc.) spin SMMs; (6) preparing and characterizing new SMMs with transport properties; (7) attaching SMMs to functionalized metal surfaces or to polymers; (8) developing SMMs with photon accessibility; (9) preparing non-compensated spin SMMs doping S = 0 antiferromagnetic rings and polynuclear complexes; and (10) discovering why certain Mn12 SMMs exhibit magnetization tunneling with one-half the activation energy of other Mn12 SMMs. Single molecule magnets offer the potential for data storage on the nanoscale and other applications. This research is to develop new types of single molecule magnets and study the new quantum effects they present. Collaborations involve physics groups in three different countries and several chemistry groups, which will enhance the research training of a diverse group of graduate and undergraduate students.