Reactions of platinum(II) aqua complexes. 3. Multinuclear (15N, 195Pt, 13C, and 1H) NMR study of reactions of aqua and hydroxo complexes with glycine and (methylimino)diacetic acid

Pt(H2O)4 2+ with glycine (glyH) gives Pt(H2O)3(glyH-O)2+ and Pt(H2O)2(glyH-O)2 2+ and with (methylimino)diacetic acid (midaH2) Pt(H2O)3(midaH2-O)2+. The mida complex, when heated, does not give mer-Pt(mida)(H2O) but a complex mixture of species, probably with Pt-N-CH2CO2-Pt bridging. cis-Pt(NH3)2(H2O)2 2+ with glycine gives cis-Pt(NH3)2(glyH-O)(H2O)2+, characterized by 15N, 195Pt, 13C, and 1H NMR, which only slowly converts to the chelate complex Pt(NH3)2(gly-N,O)+. Analogous reactions occur with midaH2. cis-Pt(NH3)2(OH)2 in alkaline solution reacts slowly with glycinate to give cis-Pt(NH3)2(gly-N)2 and cis-Pt(NH3)2(gly-N)(OH).