Efficient and stereoselective syntheses of isomeric trifluoromethyl-platinum(IV) chlorides

• Published in: Dalton transactions : an international journal of inorganic chemistry 2011-01, Vol.40 (40), p.10440-10447
• Main Authors: Martínez-Salvador, Sonia, Alonso, Pablo J, Forniés, Juan, Martín, Antonio, Menjón, Babil
• Format: Article
• Language: English
• Subjects: Bonding; Couples; Diffraction; Equatorial regions; Ligands; Optical properties; Precursors; Reflectivity
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c1dt10557d

The homoleptic, square-planar trifluoromethylplatinate(II) compound [NBu(4)](2)[Pt(CF(3))(4)] (1) reacts with SOCl(2) undergoing oxidative addition of a S-Cl bond to give the octahedral species [NBu(4)](2)[trans-Pt(CF(3))(4)Cl(SOCl)] (4), that contains the unusual chlorosulfinyl ligand. Compound 4 readily evolves into the dichloro-derivative [NBu(4)](2)[cis-Pt(CF(3))(4)Cl(2)] (2), whereby the "Pt(CF(3))(4)" unit undergoes a stereochemical rearrangement from an initial square-planar (equatorial) geometry to a final sawhorse disposition within the global Pt octahedral environment. Compound 2 is more reactive than the corresponding [NBu(4)](2)[trans-Pt(CF(3))(4)Cl(2)] (3) stereoisomer and thus affords the trichloro-derivative [NBu(4)](2)[fac-Pt(CF(3))(3)Cl(3)] (5) by treatment with the stoichiometrically required amount of HCl(aq). Stereoisomer [NBu(4)](2)[mer-Pt(CF(3))(3)Cl(3)] (6) has been obtained by oxidative addition of Cl(2) to the organoplatinum(II) precursor [NBu(4)](2)[Pt(CF(3))(3)Cl]. All the synthetic procedures described here proceed in high yields and in a stereoselective manner. The optical properties of the cis-/trans-[Pt(CF(3))(4)Cl(2)](2-) and fac-/mer-[Pt(CF(3))(3)Cl(3)](2-) diastereomeric couples (diffuse reflectance) as well as the solid-state geometries of the latter couple (single-crystal X-ray diffraction methods) are conveniently compared.