Insights into the acid-base properties of PtIV-diazidodiam(m)inedihyroxido complexes from multinuclear NMR spectroscopy
| Autor: | Peter J. Sadler, Ana M. Pizarro, Luca Ronconi, Ruth J. McQuitty |
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| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: |
Magnetic Resonance Spectroscopy
Organoplatinum Compounds Base (chemistry) Stereochemistry acid–base properties anticancer complexes chemistry.chemical_element Antineoplastic Agents Protonation 010402 general chemistry pKa values 01 natural sciences Catalysis bioinorganic chemistry NMR spectroscopy Deprotonation Molecule Prodrugs QD platinum Nuclear Magnetic Resonance Biomolecular QC chemistry.chemical_classification Molecular Structure 010405 organic chemistry Chemical shift Organic Chemistry Bioinorganic chemistry General Chemistry Nuclear magnetic resonance spectroscopy Full Papers 0104 chemical sciences chemistry Platinum |
| Zdroj: | Chemistry (Weinheim an Der Bergstrasse, Germany) |
| ISSN: | 0947-6539 |
| Popis: | Platinum(IV) am(m)ine complexes are of interest as potential anticancer pro-drugs, but there are few reports of their acid-base properties. We have studied the acid-base properties of three photoactivatable anticancer platinum(IV)-diazidodiam(m)ine complexes (cis,trans,cis-[Pt(IV)(N(3))(2)(OH)(2)(NH(3))(2)], trans,trans,trans-[Pt(IV)(N(3))(2)(OH)(2)(NH(3))(2)], and cis,trans-[Pt(IV)(N(3))(2)(OH)(2)(en)]) using multinuclear NMR methods and potentiometry. In particular, the combination of both direct and indirect techniques for the detection of (15)N signals has allowed changes of the chemical shifts to be followed over the pH range 1-11; complementary (14)N NMR studies have been also carried out. A distinct pK(a) value of approximately 3.4 was determined for all the investigated complexes, involving protonation/deprotonation reactions of one of the axial hydroxido groups, whereas a second pH-dependent change for the three complexes at approximately pH 7.5 appears not to be associated with a loss of an am(m)ine or hydroxido proton from the complex. Our findings are discussed in comparison with the limited data available in the literature on related complexes. |
| Databáze: | OpenAIRE |
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