Diorganotin(IV) complexes of D-galacturonic acid: solid-state and solution-phase structural study

✍ Scribed by N. Bertazzi; G. Bruschetta; G. Casella; L. Pellerito; E. Rotondo; M. Scopelliti

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 145 KB
• Volume: 17
• Category: Article
• ISSN: 0268-2605
• DOI: 10.1002/aoc.556

✦ Synopsis

Three diorganotin(IV) complexes of D-galacturonic acid (H 2 GalA; R = Me, n-Bu, Ph), two of which are new derivatives (R = Me, Ph), have been synthesized and their solid-state and solution-phase investigated by IR, M össbauer, 1 H, 13 C and 119 Sn NMR spectroscopy. The FTIR data suggest that H 2 GalA, in the dialkyltin derivatives, behaves as a dianionic ligand, coordinating the tin(IV) atom through an ester-type carboxylate and deprotonated alcoholic hydroxo groups, whereas a bridging carboxylate occurs in the diphenyltin(IV) complex. Octahedral and trigonal bipyramidal local geometries on tin(IV) atoms are proposed for dialkyltin(IV)GalA and diphenyltin(IV)GalA complexes respectively on the basis of M össbauer spectroscopy. In D 2 O solution, R 2 Sn(IV) moieties seem to be mainly coordinated by the GalA 2-in the β-furanosidic (β-GalfA 2-) form, involving the β-furanosidic ring in rotational equilibrium. However, the α-furanosidic (α-GalfA 2-), α-pyranosidic (α-GalpA 2-) and the β-pyranosidic (β-GalpA 2-) isomers are also involved in the coordination upon the tin atom to a minor extent. In DMSO-d 6 solution, R 2 Sn(IV) moieties are coordinated almost entirely by the GalA 2-in the β-furanosidic form.