HEAVY-METAL-NUCLEOSIDE INTERACTIONS .13. SYNTHESIS AND SPECTROSCOPIC STUDY OF ORGANOMERCURY DERIVATIVES OF GUANOSINE AND THYMIDINE

Complexes of the stoichiometry RHg(GuoH-1), [RHg(Guo)]NO3, and [(RHg)2GuoH-1]NO3 have been synthesized by reaction of the nucleoside guanosine (Guo) and RHg11 in water (R=Me) or aqueous ethanol (R=Ph). Comparison of infrared spectra of the solid complexes and 1H nuclear magnetic resonance spectra of the complexes in dimethyl-d6 sulfoxide with spectra of Guo, [GuoH]NO3, and Na[GuoH-1]·H2O allows assignment of structures for these ambidentate ligand complexes. Deprotonation of N1 of Guo leads to coordination of RHgII at N1 in RHg(GuoH-1) and to both N1 and N7 in [(RHg)2GuoH-1]NO3. The complexes [RHg(Guo)]NO3 have RHgII bonded at N7 of the guanine base. Phenylmercuric hydroxide reacts with thymidine (dThd) in aqueous ethanol to form PhHg(dThdH-1)·H2O with PhHgII bonded to N3 after deprotonation of dThd. Structures deduced for these solid complexes are in agreement with those suggested in earlier ultraviolet and Raman studies of the interaction of nucleosides and nucleotides with MeHgII in aqueous solution. The uses and limitations of vibrational spectra in assigning structures to such metal nucleoside complexes are outlined. © 1979, American Chemical Society. All rights reserved.