Philippe Arrizabalaga

A possible route to oxamic-platinum-blue: Nature and reactivity of a stable intermediate

SummaryOxamic acid is a ligand which offers several potential coordination sites, From its reaction in an aqueous medium with K2[Pt(NO2)4] it is possible to isolate a complex (A) which constitutes a first step in the formation of oxamic-platinum-blue (C), together with green species whose structures are much more difficult to define. Elemental analyses and i.r. spectra of such a series allow one to postulate a formation mechanism for the oxamic platinum-blues.

Palladium(II) complexes of orotic acid and derivatives: multiplicity of their binding sites

Abstract The complexes of orotic acid, 3-methyl orotic acid, 5-nitro orotic acid, and orotic acid methyl ester with [PdCl 4 ] 2− , enPdCl 2 , and [Pd(NH 3 ) 4 ] 2+ have been isolated and studied by means of uv spectroscopy. Reaction occurs over a wide pH range with the orotic acid nucleus acting as monoanion, dianion, or fully deprotonated as trianion.

Platinum blues. Experimental support for the occurence of platinum(III) in a blue compound involving 1-methylnicotinamide and guanosine as ligands

Abstract A blue platinum complex involving guanosine and 1-methylnicotinamide has been obtained in a two-step reaction. The coordination sites on both ligands have been deduced from a spectrometric ( 1 H and 13 C NMR, visible and infrared) study. Analysis of the EPR hyperfine pattern strongly suggests that the actual paramagnetic centers are platinum(III) ions and the complex has to be considered as a localized mixed-valence species.

REDUCTIVE PROPERTIES OF THIOAMIDES IN COMPLEX FORMATION MIXED-VALENCE COMPLEXES OF PLATINUM FROM THIOHYDANTOIN

Abstract Mixed valence complexes have been obtained using in a one pot synthesis the complexing and reducing properties of thiohydantoin (ThH). Two complexes, i.e. [Pt(ThH)4][PtCI6] and [Pt(Th)2][Pt(ThH)2CI4] have been obtained. These complexes having platinum atoms in two different oxidation states and bridged by halogen atoms are compared in view of their conductive properties to the classical class II mixed valence complexes such as Wolfframs red salt.

Platinum Blues - a Study of the Interaction between Potassium Tetrachloroplatinate and Asparagine

Abstract Potassium tetrachloroplatinate and asparagine form a paramagnetic complex in aqueous solution. This complex which displays a blue green color has been studied by ESR and IR spectroscopy. The ESR spectra are interpreted to be due to tervalent platinum in a low spin d7 configuration. The IR data suggest that the doubly deprotonated ligand is coordinated through the COO- and CONH- groups.