Reduced main group compounds: Stannides and phosphides.

Abstract

The intermetallic phase, Na$\sb4$Sn, can be synthesised by a solid state reaction starting from stoichiometric quantities of the elements. It crystallizes in the orthorhombic space group Pnam with 4 asymmetric units per unit cell (a = 9.744(3)A, b = 22.751(10)A, c = 5,5390(15)A). The reactivity of Na$\sb4$Sn with organic and inorganic halides, elements and organic cations was investigated. The interconversion between and $\rm P\sb{21}\sp{3-}$ and P$\sb \sp{2-}$ has been demonstrated. Coordinating solvents, such as THF and pyridine, stabilise the more reduced P$\sb{21}\sp{3-}$ while the less reduced P$\sb \sp{2-}$ is favored when a non-coordinating solvent like EtOH is used. The reaction of P$\sb{21}\sp{3-}$ with Bu$\sb3$SnCl yields the new polyphosphides P$\sb \sp{2-}.$ The structure of this new anion was deduced from $\sp{31}$p studies.