TERNARY COMPLEXES OF CIS-PT(NH3)(2)CL-2 AND TRANS-PT(NH3)(2)CL-2 (CIS-DDP, TRANS-DDP) WITH 9-METHYLGUANINE (9-MEG), THE DIPEPTIDES GLYCYLGLYCINE (GLYGLY), GLYCYL-L-ALANINE (GLYALA), GLYCYL-L-2-AMINOBUTYRIC ACID (GLY-2-ABA), GLYCYL-L-NORCRALINE (GLYNVAL), GLYCYL-L-NORLEUCINE (GLYNLEU), AND OF TRANS-PT(NH3)(2)CL-2 WITH NA-L-ACETYLHISTIDINE

The reactions of cis- and trans-[(NH3)(2)Pt(9-MeG)X]Y (X=Cl, H2O; Y=Cl, NO3, BPh(4)) with the dipeptides glygly, glyala, gly-2-aba, glynval and glynleu, and of trans-[(NH3)(2)Pt(9-MeG)X]Y with the sodium salt of Na-L-acetyl-histidine in aqueous solutions, produced the analytically pure ternary complexes cis- and trans-[(NH3)(2)Pt(9-MeG)(glygly)]Y-n, (n=1, 2) (1A, 1B), cis- and trans-[(NH3)(2)Pt(9-MeG)(glyala)]Y-n, (2A, 2B), cis- and trans-[(NH3)(2)Pt(9-MeG)(gly-2-aba)]Y-n (3A, 3B), cis- and trans[(NH3)(2)Pt(9-MeG)(glynval)]Y-n (4A, 4B), cis- and trans-[(NH3)(2)Pt(9-MeG)(glynleu)]Y-n (5A, 5B) and trans-[(NH3)(2)Pt(9-MeG)(achis-N-1,N-3)](NO3). These were characterized in the solid state with elemental analysis, IR, H-3 NMR and (195)pt NMR spectra. 9-MeG retains its N-7 coordination in the ternary complexes. Hydrophobic intramolecular ligand-ligand interactions were detected in the cis-ternary systems with H-1 NMR spectra, between 9-MeG and the dipeptides, increasing with the length of the aliphatic side chain of the latter. These were much weaker in the trans series, and might be of intermolecular nature. The trans-[(NH3)(2)Pt(9-MeG)(achis-N-1)]NO3 and trans-[(NH3)(2)Pt(9-MeG)(achis-N-3)](NO3) contained achis coordinated through the N-1 and N-3 atoms in a ratio of 0.8.