MONONUCLEAR DINUCLEAR AND TRINUCLEAR PT(II), MONONUCLEAR PT(IV), MIXED PT(II),PT(IV), MIXED PT(II),AG(I) COMPLEXES OF 9-METHYLADENINE (9-MEA), AND THE X-RAY STRUCTURE OF [(DIEN)PT(9-MEA-N1)](NO3)2.H2O

Previously studied (1H NMR) mono- and dinuclear complexes obtained by reactions of [(dien)Pt(II)] with 9-methyladenine (9-MeA) have been isolated and characterized: [(dien)Pt(9-MeA-N7)](NO3)2·H2O (1), [(dien)Pt(9-MeA-N1)](NO3)2·H2O (2) and {[(dien)Pt]2(9-MeA-N7,N1)}(NO3)4·2H2O(3). Complex 2, which is only the third structurally characterized adenine complex having a metal exclusively bound through N(1), crystallizes in the space group P1 with unit cell dimensions a=8.797(2), b=10.701(3), c=12.156(3) Å, α=101.93(3), β=118.18(3), γ=101.11(3)°, V=929.4 Å3, Z=2. Trinuclear derivatives of 2, {(NH3)2Pt[(N7-9-MeA-N1)Pt(dien)]2}(NO2)6·6H2O, (4), (5) were prepared by reaction of 2 with cis- and trans-(NH3)2Pt(II), respectively. Oxidation of 1 and 2 with H2O2 gave Pt(IV) compounds of composition trans-[Pt(OH)2(dien)(9-MeA-N7)](ClO4)2·2H2O (6) and trans-[Pt(OH)2(dien)(9-MeA-N1)]X2·nH2O (X=ClO4-, n=2 (7a); X=NO3-, n=0, (7b)). The mixed Pt(IV),Pt(II) complex trans- [(OH)2Pt(dien)(N1-9-MeA-N7)Pt(dien)](ClO4)4·2H2O (8) was obtained from 7 and (dien)Pt(II). The compounds prepared were characterized by elemental analysis and a variety of spectroscopic methods such at 1H NMR, UV and Raman. Acid-base equilibria were determined for several of the compounds and the formations of heteronuclear complexes between Ag+ and 1 and 2, respectively, were followed by 1H NMR. © 1990.