Interaction of Et2SnCl2 with 5'-IMP and 5'-GMP.

The interactions of Et2SnCl2 with 5'-IMP and 5'-GMP have been studied in aqueous solutions by 1H- and 31P-NMR spectroscopy as a function of pH. At low pH values (< 4.0) Sn(IV) interacts with the pyrophosphate oxygens of these nucleotides. At intermediate pH values (4-9.5) no interaction of the metal with the nucleotides take place, while at pH > 9.5 the sugar O'2 and O'3 atoms are the preferred coordination sites. In addition, the solid adducts obtained from aqueous solutions at pH = 3-4 of the above interactions correspond to formulae; (Et2Sn)2(5'-IMP)2(H2O) and (Et2Sn)3(5'-GMP)2(OH)2(H2O)2 as their elemental analysis show. IR spectra and solid state 13C, 31P-NMR spectra 119Sn Mössbauer and solution 119Sn-NMR spectra once more confirm the pyrophosphate involvement in bonding with Sn(IV) in oligomeric or polymeric structures and trigonal bipyramidal or octahedral geometries.