• Bond, Alan
• Junk, Peter
• Boas, John

Abstract

<p>The bulk oxidative electrolysis of a 2 mM solution of trans-[Pt^II{(p-HC₆F₄)NCH₂CH₂NEt₂}Cl(py)] in highly non-coordinating dichloromethane (0.05 M [Bu₄N][B(C₆F₅)]) media leads to the formation of about 14% of the Pt^III species trans-[Pt^III{(p-HC₆F₄)NCH₂CH₂NEt₂}Cl(py)]⁺. The EPR spectrum of this electro-synthesized formally Pt^III species shows Pt-hyperfine coupling with g_x ~ g_y &gt; g_z ~ g_e, and is broadly consistent with the simple crystal field theory prediction for 5d⁷ Pt^III in an elongated tetragonal environment where the unpaired electron is in a 5d(z²) orbital. The crystal field calculations lead to an estimate of the 5d(z²) character of around 37% and indicate partial delocalization of the unpaired electron onto the orbitals of the surrounding ligands. Transient cyclic voltammetric and steady-state microelectrode studies in the same media as used for bulk electrolysis exhibit a chemically reversible one electron oxidation process under their shorter time scale conditions. Analysis of X-ray diffraction data obtained from a single crystal of trans-[Pt^II{(p-HC₆F₄)NCH₂CH₂NEt₂}Cl(py)] shows the square planar geometry of the ligands around the Pt metal center and the ‘W’ arrangement of the ethyl groups on the ligand is explained in terms of agostic interactions.</p>

Topics

• impedance spectroscopy
• compound
• single crystal
• x-ray diffraction
• theory
• electron spin resonance spectroscopy