Iqbal Mohd, Naina Vanitha R, Sun Xiaofei, Roesky Peter W
Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Kaiserstr 12, 76131, Karlsruhe, Germany.
Institute for Nanotechnology, Karlsruhe Institute of Technology (KIT), Kaiserstr 12, 76131, Karlsruhe, Germany.
Chemistry. 2025 Oct 1;31(55):e02313. doi: 10.1002/chem.202502313. Epub 2025 Aug 11.
The distinctive electronic properties and wide range of applications of cyclooctatetraene (COT) sandwich complexes make exploring this class of compounds essential. The new phosphine-functionalized proligand 1,4-bis(dimethylsilylmethyl)diphenylphosphinecycloocta-2,5,7-triene, {CH-1,4-(MeSiCHPPh)}, was synthesized by reaction of KCOT with MeSi(Cl)CHPPh first. Subsequent deprotonation with various alkali metal bases led to a series of alkali metal complexes [M{CH-1,4-(MeSiCHPPh)}] (M = Na, K, Rb, Cs). Notably, the crystallization solvent and the alkali metals significantly influenced the polymeric architecture and led to structural diversity of all complexes. For instance, the two phosphine arms either coordinate both to one metal atom, while the other metal ion is uncoordinated, or, in other structures, each metal atom is equally coordinated by just one phosphine function. Additionally, the coordination behavior of the pendant phosphine groups determines the emissive nature of these complexes. In all cases, polymeric structures are formed, in which intermolecular interactions between the COT ring and a metal atom are observed. Additionally, Rb forms a benzene-bridged eight-membered polymeric structure [{Rb(CH-1,4-(MeSiCHPPh)) (CH)}]. Additionally, the lighter alkali metals in [M{CH-1,4-(MeSiCHPPh)}] can be exchanged by the heavier congeners by using the corresponding tert-butoxides.
环辛四烯（COT）夹心配合物独特的电子性质和广泛的应用使得探索这类化合物至关重要。新型膦功能化前体配体1,4-双（二甲基硅基甲基）二苯基膦环辛-2,5,7-三烯，{CH-1,4-(MeSiCHPPh)}，首先通过KCOT与MeSi(Cl)CHPPh反应合成。随后用各种碱金属碱进行去质子化反应，得到了一系列碱金属配合物[M{CH-1,4-(MeSiCHPPh)}]（M = Na、K、Rb、Cs）。值得注意的是，结晶溶剂和碱金属显著影响聚合物结构，并导致所有配合物的结构多样性。例如，两个膦臂要么都与一个金属原子配位，而另一个金属离子未配位，或者在其他结构中，每个金属原子仅由一个膦官能团同等配位。此外，侧链膦基团的配位行为决定了这些配合物的发光性质。在所有情况下，都会形成聚合物结构，其中观察到COT环与金属原子之间的分子间相互作用。此外，Rb形成了一种苯桥连的八元聚合物结构[{Rb(CH-1,4-(MeSiCHPPh)) (CH)}]。此外，通过使用相应的叔丁醇盐，[M{CH-1,4-(MeSiCHPPh)}]中的较轻碱金属可以被较重的同系物取代。
