Dicopper phosphandiides

A series of metal-rich, coin-metal containing phosphanediyl clusters (phosphandiides) with additional terminal donor ligands (i.e., triorga-nophosphanes) have been prepared only one example of a donor-free dicopper phosphandiide has been reported up to now (37, 38). Thus, the neutral cluster 16 has been prepared by the reaction of the primary phosphane la with CuOfBu in toluene at 60°C and has been isolated in 81% yield in the form of dark red crystals that are only sparingly soluble (39) ... 

In contrast to magnesium phosphandiides, analogous tin(II) derivatives possess more covalent metal-phosphorus bonds. This basic difference is also apparent for dilithium versus dicopper(I) phosphandiides (see Section II and III). It is, therefore, interesting to assess the structural and electronic features of such species in a similar way. To date, only three tin(II) phosphandiide derivatives have been prepared... 

---