Mono-, di- 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)](NO 3) 2·H 2O

Abstract

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- N 7)](NO 3) 2·H 2O ( 1), [(dien)Pt(9-MeA- N 1)](NO 3) 2·H 2O ( 2) and {[(dien)Pt] 2(9-MeA- N 7, N 1)}(NO 3) 4·2H 2O(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 P 1 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 Å 3, Z=2. Trinuclear derivatives of 2, {(NH 3) 2Pt[( N 7-9-MeA- N 1)Pt(dien)] 2}(NO 2) 6·6H 2O, ( 4), ( 5) were prepared by reaction of 2 with cis- and trans-(NH 3) 2Pt(II), respectively. Oxidation of 1 and 2 with H 2O 2 gave Pt(IV) compounds of composition trans-[Pt(OH) 2(dien)(9-MeA- N 7)](ClO 4) 2·2H 2O ( 6) and trans-[Pt(OH) 2(dien)(9-MeA- N 1)]X 2· nH 2O (X=ClO 4 −, n=2 ( 7a); X=NO 3 −, n=0, ( 7b)). The mixed Pt(IV),Pt(II) complex trans- [(OH) 2Pt(dien)( N 1-9-MeA- N 7)Pt(dien)](ClO 4) 4·2H 2O ( 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.