Use of a cyclo-P(4) building block – a way to networks of host–guest assemblies

Despite the proven ability to form supramolecular assemblies via coordination to copper halides, organometallic building blocks based on four-membered cyclo-P(4) ligands find only very rare application in supramolecular chemistry. To date, only three types of supramolecular aggregates were obtained based on the polyphosphorus end-deck complexes Cp(R)Ta(CO)(2)(η(4)-P(4)) (1a: Cp(R) = Cp′′; 1b: Cp(R) = Cp′′′), with none of them, however, possessing a guest-accessible void. To achieve this target, the use of silver salts of the weakly coordinating anion SbF(6)(−) was investigated as to their self-assembly in the absence and in the presence of the template molecule P(3)Se(4). The two-component self-assembly of the building block 1a and the coinage-metal salt AgSbF(6) leads to the formation of 1D or 3D coordination polymers. However, when the template-driven self-assembly was attempted in the presence of an aliphatic dinitrile, the unprecedented barrel-like supramolecular host–guest assembly P(3)Se(4)@[{(Cp′′Ta(CO)(2)(η(4)-P(4)))Ag}(8)](8+) of 2.49 nm in size was formed. Moreover, cyclo-P(4)-based supramolecules are connected in a 2D coordination network by dinitrile linkers. The obtained compounds were characterised by mass-spectrometry, (1)H and (31)P NMR spectroscopy and X-ray structure analysis.