Hexameric organotincarboxylates with cyclic and drum structures

Abstract

The interaction of 3,5-diisopropylsalicylic acid (DIPSA) with [ⁿBu₂Sn(O)] in benzene proceeds with elimination of water to produce stannoxane [ⁿBu₂Sn(3,5-ⁱPr₂C₆H₂(O)(COO))]₆ (1), while an analogous reaction of DIPSA with [ⁿBuSn(O)(OH)] leads to the isolation of [ⁿBuSn(O)(3,5-ⁱPr₂C₆H₂(OH)(COO))]₆ (2). The new products have been characterized by elemental analysis and EI-MS, IR, and NMR (¹H, ¹³C, and ¹¹⁹Sn) spectroscopy. The molecular structure of 1 determined by single-crystal X-ray diffraction studies reveals a rare cyclic hexameric structure. The tin atoms are pentacoordinated with distorted trigonal-bipyramidal geometry. Complex 2 is also a hexameric cluster, but existing in a more common drum-like structure where the tin centers are hexacoordinated.