catena-Poly[[(tetra­hydro­furan-κO)potas­sium]-di-μ-dimethyl­amido-κ(4) N:N-aluminium-di-μ-dimethyl­amido-κ(4) N:N-potassium-di-μ-dimethyl­amido-κ(4) N:N-aluminium-di-μ-dimethyl­amido-κ(4) N:N]

The title compound, [Al(2)K(2)(C(2)H(6)N)(8)(C(4)H(8)O)](n), formed during the sonochemical reaction between Al(NMe(2))(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 AlN(2)K 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)°.