catena-Poly[[(tetra­hydro­furan-κO)potas­sium]-di-μ-dimethyl­amido-κ⁴N:N-aluminium-di-μ-dimethyl­amido-κ⁴N:N-potassium-di-μ-dimethyl­amido-κ⁴N:N-aluminium-di-μ-dimethyl­amido-κ⁴N:N]

The title compound, [Al₂K₂(C₂H₆N)₈(C₄H₈O)]_n, formed during the sonochemical reaction between Al(NMe₂)₃ and sodium–potassium alloy in the presence of tetra­hydro­furan (THF). Its asymmetric unit has two inequivalent K⁺ sites. One site is coordinated by a THF ligand, and crystallizes as a one-dimensional polymer with a backbone of catenated AlN₂K rings. A twofold rotation axis bis­ects one K⁺ site and the THF ligand; the second K⁺ site is situated on an inversion centre, resulting in a planar four-coordination by N atoms. The latter symmetry operation generates the second half of the THF mol­ecule and fills out the coordination sphere of the potassium sites. The chains extend along the c-axis direction and zigzag at the THF-coordinated K⁺ sites by an angle of 106.02 (5)°.