Synthesis and characterization of some organotin(IV) adducts containing a related series of pyridines: Crystal structure of [SnMe2Cl2(bu2bpy)]

Organotin(IV) complexes of [SnR(4−n)Cln] (n = 2, R = Me, nBu; n = 1, R = Ph) react with the bidentate pyridyl ligand 4,4′-di-tert-butyl-2,2′-bipyridine (bu2bpy) to give hexa-coordinated adducts with the general formula [SnR(4−n)Cln(bu2bpy)]. However, the reaction of these organotin(IV) complexes with the corresponding monodentate ligand 4-tert-butylpyridine (bupy) resulted in the formation of the hexa-coordinated complex [SnMe2Cl2(bupy)2] and the penta-coordinated complexes [SnR(4−n)Cln(bupy)] (n = 2, R = nBu; n = 1, R = Ph). Moreover, the reaction of the above organotin(IV) complexes with 4,4′-trimethylenedipyridine (tmdp) yields hexa-coordinated adducts with the general formula [SnR2Cl2(tmdp)] (R = Me, nBu) and the penta-coordinated complex [ClPh3Sn-μ-(tmdp)SnPh3Cl] in the solid state. The resulting complexes have been characterized by multinuclear NMR (1H, 13C, 119Sn) spectroscopy and elemental analysis. NMR data shows that the triphenyltin(IV) adducts are not stable in solution and dissociate to give tetra-coordinated tin(IV) complexes. The X-ray crystal structure determination of [SnMe2Cl2(bu2bpy)] reveals that the tin atom is hexa-coordinated in an octahedral geometry with a trans-[SnMe2] configuration.

Graphical abstractThe synthesis and characterization of some penta- and hexa-coordinated organotin(IV) complexes obtained from the reaction of a series of pyridines, 4,4′-di-tert-butyl-2,2′-bipyridine, 4-tert-butylpyridine and 4,4′-trimethylenedipyridine, with SnR2Cl2 (R = Me, nBu) and SnPh3Cl are reported. The crystal structure of [SnMe2Cl2(bu2bpy)] shows that the coordination geometry about the tin atom is octahedral, with a trans-[SnMe2] moiety.Figure optionsDownload full-size imageDownload as PowerPoint slide