Oligonuclear carboxylate-brigded transition metal complexes as a) heteronuclear coordination compounds, b) coordination compounds with redox non-innocent ligands, c) complexes with additional organometallic capping groups

含有一个以上金属离子的分子物种提供了金属中心之间合作行为的可能性，这可能导致新的性质和反应活性。自然界利用酶的这种合作性质来催化几个不同的过程，但此外，寡核金属配合物在分子磁体领域是基本感兴趣的，研究最彻底的单分子磁体的例子是氧桥和羟桥多金属体系。通过改变自旋系统来研究电子性质的系统变化，以便建立具有额外的自旋携带有机单元的异金属化合物或金属络合物的磁结构关系。在该项目中，我们将利用新的合成策略，从众所周知的过渡金属簇合物开始，制备新的配位化合物作为构建块。通过X射线结晶学、穆斯堡尔和紫外可见等光谱方法以及磁化率测量，将获得并详细研究杂多核配合物和含有氧化还原活性配体的化合物。这项研究的成功实施将使人们对包括各种自旋中心在内的新的同多金属和杂多金属化合物的合成策略有一个深刻的理解。我们在研究具有碱性羧酸基的多核铁体系的磁-结构相关性方面的长期兴趣和经验为我们成功地开展有序多维自旋阵列项目提供了基础。

Molecular species containing more than one metal ion offer the possibility of co-operative behavior between the metal centers, which may lead to new properties and reactivity. Nature utilizes such co-operative properties in enzymes that catalyze several different processes, but moreover oligonuclear metal complexes are of fundamental interest in the field of molecule-based magnets, with the most thoroughly investigated examples of single molecule magnets being oxo- and hydroxo-bridged polymetallic systems. The systematic variation of the electronic properties by means of varying the spin system will be studied spectroscopically and magnetically in order to establish magneto-structural relationships for heterometallic compounds or metal complexes with additional spin carrying organic units. In the project we will prepare new coordination compounds starting from well-known transition metal clusters as building blocks using new synthetic strategies. Heteropolynuclear complexes and compounds bearing redox-active ligands will be obtained and studied in detail by X-ray crystallography, spectroscopic methods like Mössbauer and UV-Vis as well as magnetic susceptibility measurements. Successful performance of this research will provide a profound understanding of synthetic strategies to new homo- and heteropolymetallic compounds including various spin centers. Our long-standing interest and experience in the study of magneto-structural correlations in polynuclear iron systems with basic carboxylate groups provides us with the basis to successfully carry out the project on ordered multidimensional spin arrays.