Oligophosphanid‐Anionen: Synthesen und Molekülstrukturen von [K2(PMDETA)2(P4Ph4)], [K2(PMDETA)(P4tBu4)]2 und [K(PMDETA)(THF){cyclo‐(P5tBu4)}] (PMDETA = NMe(CH2CH2NMe2)2)

Oligophosphanide Anions: Syntheses and Molecular Structures of K₂(PMDETA)₂(P₄Ph₄)], K₂(PMDETA)(P₄tBu₄)]₂ and K(PMDETA)(THF){cyclo‐(P₅tBu₄)}] (PMDETA = NMe(CH₂CH₂NMe₂)₂) The alkali metal tetraphosphanediides K₂(PMDETA)₂(P₄Ph₄)] ( 1 ) and K₂(PMDETA)(P₄tBu₄)]₂ ( 2 ) PMDETA = NMe(CH₂CH₂NMe₂)₂] were synthesized via reaction of PhPCl₂ or tBuPCl₂ with 2.5 equiv. potassium and characterized by X‐ray crystallography and ³¹P NMR spectroscopy. As in other ion contact complexes of the type M₂(P₄R₄) (M = alkali metal) the solid‐state structures are retained in solution. While 1 could be prepared in comparatively good yield (54 %), 2 was only isolated in very modest yield and with low purity as K(PMDETA)(THF){cyclo‐(P₅tBu₄)}] ( 3 ) was formed as a side product in this case. 3 was also characterized by X‐ray crystallography and ³¹P NMR spectroscopy.