Metal–organic complexation in the marine environment

We discuss the voltammetric methods that are used to assess metal–organic complexation in seawater. These consist of titration methods using anodic stripping voltammetry (ASV) and cathodic stripping voltammetry competitive ligand experiments (CSV-CLE). These approaches and a kinetic approach using CSV-CLE give similar information on the amount of excess ligand to metal in a sample and the conditional metal ligand stability constant for the excess ligand bound to the metal. CSV-CLE data using different ligands to measure Fe(III) organic complexes are similar. All these methods give conditional stability constants for which the side reaction coefficient for the metal can be corrected but not that for the ligand. Another approach, pseudovoltammetry, provides information on the actual metal–ligand complex(es) in a sample by doing ASV experiments where the deposition potential is varied more negatively in order to destroy the metal–ligand complex. This latter approach gives concentration information on each actual ligand bound to the metal as well as the thermodynamic stability constant of each complex in solution when compared to known metal–ligand complexes. In this case the side reaction coefficients for the metal and ligand are corrected. Thus, this method may not give identical information to the titration methods because the excess ligand in the sample may not be identical to some of the actual ligands binding the metal in the sample

Determination of Pt–DNA adducts and the sub-cellular distribution of Pt in human cancer cell lines and the leukocytes of cancer patients, following mono- or combination treatments, by inductively-coupled plasma mass spectrometry

This is the author’s version of a work that was accepted for publication in the International Journal of Mass Spectrometry. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published at: http://dx.doi.org/10.1016/j.ijms.2010.11.01

Ab initio calculations on cis-[ PtCl

The capacity of Hartree-Fock (HF), Møller-Plesset second order perturbation (MP2), and density functional (DF) calculations to predict the experimental dipole moment and the metal-ligand bond lengths of a planar platinum(II) complex, cis-[ PtCl2(PMe3)2] , was investigated. Highly erroneous results were obtained from uncorrelated HF calculations and from MP2 and DF calculations which included the 5s and 5p electrons of platinum in a frozen core or in an effective core potential. DF calculations including these (n-1)s and (n-1)p electrons in the valence space are shown to have the ability to correctly reproduce the platinum-ligand bond lengths and the dipole moment, provided that sufficiently large basis sets including polarization functions are used. MP2 calculations yielded dipole moments comparable to those obtained from DF calculations with the same basis set and reproduced better the difference between the Pt-Cl and Pt-P bond lengths, but required 2-6 times more computer time. The best agreement between calculated and experimental dipole moment and bond length values was obtained with DF calculations using the program ADF, provided that the scalar relativistic terms were included in the hamiltonian. Our results indicate that the mutual influence of the platinum-ligand bonds in trans-position (the so-called trans-influence) involves both electron correlation and relativistic effects

cis-Dichloro(di-n-butyl sulfide)(tri-n-butylphosphine)platinum(II)

International audienc

Reaction between the diaqua form of cisplatin and 2-methylsulfanylphenylphosphonic acid yields a dinuclear phosphonato-bridged complex via NH3 elimination

Reaction between cis-[Pt(NH3)(2)(H2O)(2)](2+) and (2-methylsulfanyl)phenyl phosphonic acid (H(2)mspp) did not yield the expected cis-diammine [(2-methylsulfanylphenyl)phosphonato]platinum(II) but the dimeric compound [(Pt(mspp)(NH3)}(2)] . 6H(2)O in which the dianionic mspp(2-) ligand acts both as chelator and bridging ligand. Thus, the high trans-effect of the sulfanyl group apparently leads to elimination of one NH3 ligand. An X-ray crystal structure analysis of the dimeric complex is reported