Halogen exchange in complexes of hexacoordinate tin (L n CH 2 ) 2 SnX 2 and (L n CH 2 ) 2 SnY 2 containing lactamomethyl n-membered C,O-chelate ligands L n CH 2 (n = 5–7; X, Y = Cl, Br, I)

Halogen exchange reactions between hexacoordinate tin dihalides (LnCH2)2SnX2 and (LnCH2)2SnY2 (LnCH2 = C,O-chelate n-membered lactamomethyl ligand, n = 5–7, X, Y = Cl, Br, I) produce mixed dihalides (LnCH2)2SnXY. Along with the signals of original complexes, NMR 119Sn spectra of solutions containing two different homodihalides show the third signal with a median chemical shift. The results of NMR monitoring studies, conductivity data and quantum-chemical calculations suggest that mixed dihalides readily form in solutions, although these complexes have not been isolated as individual compounds.