Catalytic ways to new inorganic polymers: development of transition metal catalysts for highly selective dehydropolymerisation of amine boranes

近年来，所谓的无机聚合物领域取得了重大进展。作为普遍存在的聚烯烃的无机类似物的聚（氨基硼烷）代表了这种类型的化合物的实例，其具有仅含有硼和氮的聚合物主链。这些结构在BN/CC等排性的背景下以及作为新的含B-N材料的预陶瓷具有基础性和面向应用的兴趣。 胺硼烷前体本身、聚（氨基硼烷）或用于合成非均相材料的反应条件（即，温度、气氛、金属掺杂剂）可以在主族材料的化学中开辟新的途径，包括在多相催化中的应用。在本项目的框架内，将把以前关于甲胺-硼烷催化脱氢聚合的项目中获得的知识扩展到基于第9族金属的新催化剂。以前的研究表明，主要是铑配合物以及与钳形配体的配合物催化该反应，对所需的聚合物具有高选择性。在现在提出的调查中，这种方法是系统地追求进一步和扩展到包括使用钳配体与可修改的二级配位球的金属配体合作的结合，活化，脱氢，和胺硼烷的耦合。我们将进一步评估取代膦基配体的可能性。该项目将有助于对反应机理的理解，以及开发用于伯胺硼烷选择性脱氢聚合的新催化剂。此外，将研究大规模合成聚（氨基硼烷）作为新的，可改性的B-N材料的前体的可能性。

The field of so-called inorganic polymers has seen significant advances in recent years. Poly(aminoborane)s as inorganic analogues of ubiquitous polyolefins represent examples for compounds of this type, possessing a polymer main chain that exclusively contains boron and nitrogen. These structures are of fundamental and application-oriented interest in the context of BN/CC isosterism and as pre-ceramics for new B-N containing materials. Modification of the amine borane precursor itself, the poly(aminoborane), or the reactions conditions used for the synthesis of heterogeneous materials (i.e., temperature, atmosphere, metal dopants) could open new avenues in the chemistry of main group materials, including applications in heterogeneous catalysis. Within the framework of this project, the knowledge gained in the previous project on the catalytic dehydropolymerisation of methylamine-borane is to be extended to new catalysts based on group 9 metals. Previous investigations showed that mainly rhodium complexes as well as complexes with pincer ligands catalyse this reaction with high selectivity for the desired polymer. In the investigations now proposed, this approach is to be systematically pursued further and extended to include the use of pincer ligands with a modifiable secondary coordination sphere for metal-ligand cooperative binding, activation, dehydrogenation, and coupling of amine boranes. We will furthermore evaluate possibilities to replace phosphine-based ligands. The presented project will contribute to the mechanistic understanding of the reaction as well as to the development of new catalysts for the selective dehydropolymerisation of primary amine boranes. Furthermore, the possibility of synthesising poly(aminoboranes) on a large scale for use as precursors for new, modifiable B-N materials will be investigated.