Phosphonato complexes of platinum(II): kinetics of formation and phosphorus-31 NMR characterization studies

Journal Article · Sat Dec 01 04:00:00 EST 1990 · Journal of Inorganic Biochemistry; (USA)

DOI:https://doi.org/10.1016/0162-0134(90)80068-9· OSTI ID:5770057

Slavin, L L; Bose, R N ^[1]

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1. Chemistry Department, Kent State University, OH (USA)

Reactions of cis-diamminedichloroplatinum(II) with phosphonoformic acid (PFA), phosphonoacetic acid (PAA), and methylenediphosphonic acid (MDP) yield various phosphonatoplatinum(II) chelates which were characterized by phosphorus-31 NMR spectroscopy. The P-31 resonances for the chelates appear at 6-12 ppm downfield as compared to the uncomplexed ligands. All complexes exhibit monoprotic acidic behavior in the pH range 2-10. The chemical shift-pH profiles yielded acidity constants, 1.0 x 10(-4), 1.5 x 10(-4), and 1.3 x 10(-6) M-1, for the PFA, PAA, and MDP chelates. In addition to the monomeric chelate, MDP formed a bridged diplatinum(II,II) complex when it reacted with cis-Pt (NH3)2(H2O)2(2)+. The P-31 resonance for this binuclear complex appears at 22 ppm downfield from the unreacted ligand. Rate data for the complexation reactions of the phosphonate ligands with the dichloroplatinum complex are consistent with a mechanism in which a monodentate complex is formed initially through rate-limiting aquation process of the platinum complex, followed by a rapid chelation. For the PFA and PAA complexes, initial binding sites are the carboxylato oxygens. Implications of the various binding modes of the phosphonates in relationship to their antiviral activities are discussed.

• OSTI ID: 5770057
• Journal Information: Journal of Inorganic Biochemistry; (USA), Journal Name: Journal of Inorganic Biochemistry; (USA) Vol. 40:4; ISSN JIBID; ISSN 0162-0134
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
BIOCHEMICAL REACTION KINETICS
CHELATING AGENTS
CHEMICAL SHIFT
COHERENT SCATTERING
COMPLEXES
DIFFRACTION
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LIGANDS
LIGHT NUCLEI
MAGNETIC RESONANCE
MEMBRANE PROTEINS
NMR SPECTRA
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PHOSPHONIC ACIDS
PHOSPHORUS 31
PHOSPHORUS ISOTOPES
PROTEINS
REACTION KINETICS
RECEPTORS
RESONANCE
SCATTERING
SPECTRA
STABLE ISOTOPES
TRACER TECHNIQUES
X-RAY DIFFRACTION