Single Molecule Magnets

无机化学、生物无机化学和金属有机化学项目的这一奖项支持David N.Hendrickson教授更好地控制单分子磁体(SMM)的量子特性的研究。我们将研究在常温下溶液中化学合成的具有明确结构的单分散纳米磁体中的磁化强度的量子隧道效应。SMM将通过敏感的电子顺磁共振方法、核磁共振(核磁共振)和磁测量技术进行表征。这项研究的目标包括：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的机制；(3)追求分子间磁交换相互作用对QTM的影响；(4)研究SMM的性质如何从具有较大自旋的分子，如S=13，到具有较小自旋的分子，如S=4；(5)详细研究半整数(如S=9/2，13/2等)所表现出的自旋宇称效应。自旋自旋SMM的研究包括：(6)制备和表征具有输运性质的新型SMM；(7)将SMM连接到功能化的金属表面或聚合物上；(8)开发具有光子可访问性的SMM；(9)制备掺杂S=0的反铁磁环和多核复合体的非补偿自旋SMM；以及(10)发现为什么某些Mn12 SMM表现出磁化隧道效应，激活能是其他Mn12 SMM的一半。单分子磁体为纳米尺度的数据存储和其他应用提供了潜力。这项研究是为了开发新型的单分子磁体，并研究它们所呈现的新的量子效应。合作涉及三个不同国家的物理小组和几个化学小组，这将加强对不同群体的研究生和本科生的研究培训。

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.