Synthese, Kristallstrukturen und quantenchemische Untersuchung von Verbindungen mit leiterartigem Al4P4- und hexagonal prismatischem Al6P6-Grundgerüst
Abstract
The reaction of AlCl3 with Li2PR (R = SiiPr3, SiMeiPr2) in a mixture of heptane and ether yields in the polycyclic compounds [(AlCl)4(μ3-PR)2(μ-PR)2(Et2O)2](1a: R = SiiPr3; 1b: SiMeiPr2) with a ladder-shaped Al4P4 core. The coordination sphere of the outer aluminium atoms in these compounds is completed by ether ligands. In contrast, the reaction of AlCl3 with Li2PSiiPr3 in pure heptane yields in the formation of the hexagonal prismatic compound [(AlCl)6(μ3-PSiiPr3)6](2). 1 and 2 were characterized by single crystal X-ray diffraction analysis as well as by 31P{1H} and 27Al NMR spectroscopy. The structure determining effect of the solvent can be rationalized by quantumchemical calculations, which also show that the hexagonal prismatic structure is the most stable of the investigated oligomers in absence of ether.
