Organotin metalloligands for selective sensing of metal ions

Abstract

The synthesis of four new organotin carboxylates, [(t-C₄H₉)₂Sn(L₁)₂] (1), [(t-C₄H₉)₂Sn(L₂)₂] (2), [{(n-C₄H₉)₂Sn(L₁)}₂O]₂ (3) and [{(n-C₄H₉)₂Sn(L₂)}₂O]₂ (4), is reported. All complexes have been characterized by ¹H, ¹³C{¹H} and ¹¹⁹Sn{¹H} NMR spectroscopy, elemental analysis and single crystal X-ray diffraction. Complexes 1 and 2 are monomers and contain a six-coordinated tin centre, while both five- and six-coordinated tin centres are observed in the tetrameric structures of 3 and 4. All complexes selectively recognize Cu(II) and Fe(III) ions in solution. Complex 1 was found to be the best one for sensing those ions among all complexes.