Magnetic Properties of Multinuclear Titanium Complexes

多核钛配合物的磁性

• 批准号: 25249840
• 负责人: Professor Dr. Rüdiger Beckhaus
• 金额: --
• 依托单位: Institut für Chemie (IfC)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2009-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/25249840?language=en
• 关键词: Magnetic; Properties; Multinuclear; Titanium; Complexes

Self-assembly of well defined molecular architectures is attracting a huge international research effort. While such work has yielded systems with novel photophysical (e. g. light-harvesting) and electrochemical properties, surprisingly little work has been carried out on assemblies with novel magnetic behaviour. However, the knowledge of the magnetic behaviour of early transition metal multinuclear complexes employing d1, d2 or d3 metal centers is comparatively low. We have found, that discrete molecular architectures (molecular triangular, square and rectangular) can be build up by using low valent titanium complexes and bridging bisazine molecules like pyrazine, pyrimidine, 4,4¿-bipyridine or quinoxalines. The formation of the molecular architectures is often accompanied by simultaneously occurring C-C couplings of primary formed radical anions or by C-H bond activation and dehydrogenative C-C couplings leading to attractive trinucleare HAT type (1,4,5,8,9,12-hexaazatriphenylene) as well as HATN titanium (1,6,7,12,13,18-hexaazatrinaphthylene) complexes. Generally, polypyridyl compounds constitute an attractive class of organic ligands, which have been widely used for the preparation of supramolecular species which are potentially useful to understand energy as well as electron transfer processes. In this project we want investigate the magnetic behaviour of multinuclear low valent titanium complexes as a function of the molecular arrangement, the oxidation and the spin state of the involved metal centers in homo and mixed valent complexes. Particularly, investigation to compare the magnetic properties of molecular squares with tetrahedral like arranged aggregates depending on the nature of the bridging ligands are of interest. The magnetic properties should be correlated with the electrochemical behaviour, the photophysical properties as well as the MO situation characterized by DFT calculation. At the end switchable systems based on early transition metals could becomes possible.

明确的分子结构的自组装吸引了巨大的国际研究努力，虽然此类工作已经产生了具有新颖的光物理（例如光捕获）和电化学特性的系统，但令人惊讶的是，在具有新颖的磁性行为的组装方面进行的工作却很少。 ，我们发现，对于采用 d1、d2 或 d3 金属中心的早期过渡金属多核配合物的磁性行为的了解相对较少。三角形、正方形和矩形）可以通过使用低价钛配合物和桥联双嗪分子（如吡嗪、嘧啶、4,4¿）来构建-联吡啶或喹喔啉的形成通常伴随着主要形成的自由基阴离子的同时发生的C-C偶联或通过C-H键活化和脱氢C-C偶联导致有吸引力的三核HAT类型（1,4,5,8,9， 12-六氮杂苯并菲）以及 HATN 钛(1,6,7,12,13,18-六氮杂萘)配合物通常是一类有吸引力的有机配体，已广泛用于制备超分子物质，这些超分子物质可能有助于理解能量和理解能量。在这个项目中，我们想要研究多核低价钛配合物的磁性行为，作为同质和相关金属中心的分子排列、氧化和自旋状态的函数。特别是，根据桥配体的性质来比较分子方形与四面体状排列聚集体的磁性的研究值得关注，磁性应该与电化学行为、光物理性质以及化学性质相关。以 DFT 计算为特征的 MO 情况最终可能成为可能。