FAST-ATOM-BOMBARDMENT MASS-SPECTROMETRIC (FAB MS) STUDY OF THE MOLECULAR-STRUCTURE OF DI-MU-GUANINO-MU-GUANINE BIS(CIS-CHLORODIAMMINEPLATINUM(II))

A new compound of cis-chlorodiammineplatinum(II) with normal and depro tonated guanine has been synthesized and studied by FAB MS. The compou nd has a molecular structure of a binuclear complex. The mass spectrom etric behavior of the complex is dictated by the variable valence of p latinum and chemical ionization of fragments by protons, as well as by the fact that the guanine molecule bridges the two cis-PtCl(NH3)(2) g roups by its N7 and OC6 atoms and the two guanine anions bridge the gr oups by their NI and OC6 atoms. The differences in the mutual arrangem ent of the anions and the guanine molecule are responsible for the for mation of the head-to-head and head-to-tail structural isomers.