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

The interactions of Et2SnCl2 with 5'-IMP and 5'-GMP have been studied in aq ueous solutions by H-1-and P-31-NMR spectroscopy as a function of pH. At lo w 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. Tn addition, the solid adducts obtained from aqueous solutions at pH = 3-4 of the above interactions corr espond 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 C -13, P-31-NMR spectra Sn-119 Mossbauer and solution Sn-119-NMR spectra once more confirm the pyrophosphate involvement in bonding with Sn(IV) in oligo meric or polymeric structures and trigonal bipyramidal or octahedral geomet ries. (C) 1998 Elsevier Science Inc. All rights reserved.