Our approach for preparation of tetrakis-(pyridine)-difluoro-aluminum chloride was successfully deployed for the synthesis of corresponding Br and I compounds, respectively. By reacting AlX3 center dot 3Py (X = Cl, Br, I) with Me3SiF in pyridine, two of the three halogens X were substituted by fluorine atoms forming the "aluminum mixed halide" complexes AlF2X center dot 4Py with the ionic solid-state structures [Al(Py)(4)F-2]X. Whereas the Al-27 solid state NMR spectra of AlX3 center dot 3Py (X = Cl, Br) confirmed the existence of the expected singular sigma(6)lambda(3)-Al centers in their structures, the corresponding spectrum of AlI3 center dot 3Py does not contain any signal that belongs to a 6-fold coordinated Al atom. The elemental analysis data strongly support the 1:2-stoichiometry of the complex (AlI3 center dot 2Py), which in accord to the Al-27 MAS NMR spectra possessed only one sigma(4)lambda(3)-Al side as in the ionic structure [Al(Py)(2)I-2]I. AlBr3 center dot 3Py was also transformed by pyridine into the ionic complex [Al(Py)(4)Br-2]Br. The later was isolated from pyridine solutions, and its structure was determined by X-ray single crystal analysis. On the basis of our results, solvated [Al(Py)(n)X-2](+) cations are most probably the dominating species in pyridine solutions of AlX3. Thus, only two Al-X covalent bonds underwent X/F- exchange and the halogen exchange reactions were terminated at " [Al(Py)(4)F-2] stage". The hydrolysis of [Al(Py)(4)F-2]Cl by very diluted hydrochloric acid in methanol proceeded smoothly under preservation of the Al-F bonds and displacement of pyridine by water. The formation of the stable helical trans-octahedron [Al(H2O)(4)F-2](+) cation was confirmed by single-crystal XRD analysis. By reacting [Al(Py)(4)F-2]Cl with the cyclo-n-propyl-phosphonic acid anhydride [CH3CH2CH2-PO2](3), an unexpected F-migration from Al- to P- atoms was observed.