Synthesis and Structure of [{Sn₂(μ-PMes)₃}K₂·3THF]_∞, Exhibiting Multifunctional Coordination of [Sn₂(μ-PMes)₃]^2- Anions to K⁺

The reaction of Sn(NMe2)2 with MesPHK (1:2) in THF gives the title compound [{Sn2(μ-PMes)3}K2·3THF]∞ (1), having a polymeric structure in the solid state in which the [Sn2(μ-PMes)3]2- dianions behave as multifunctional σ(Sn), σ(P), and π-arene donors to K+ cations. The trigonal-bipyramidal core arrangement of the [Sn2(μ-PMes)3]2- dianion represents a monomeric unit of the metallacyclic tetraanions [{Sn(μ-PR)}2(μ-PR)]24- and of valence-isoelectronic group 14 and 15 species of the type [{MeE(μ-PR)}2(μ-PR)]4- (E = Al, In) and [{P(μ-NR)}2(μ-NR)]2.