• Nieger, Martin
• Nickolaus, Jan
• Gudat, Dietrich
• Schlindwein, Simon H.

Abstract

<p>2-Bromo- and 2-chloro-1,3,2-diazaphospholenes react with (tht)AuCl to afford isolable N-heterocyclic phosphenium (NHP) dihalido-aurates, which were characterized by analytical and spectroscopic data and in one case by a single-crystal X-ray diffraction study. The T-shaped metal coordination sphere found in the crystal consists of a pseudo-linear AuX2 unit that is perturbed by a weakly bound NHP unit. DFT studies indicate that the subunits interact mainly through electrostatic and dispersion forces, with negligible covalent contributions, and that the phosphenium dibromido-aurate is slightly more stable than an isomeric complex with an intact bromophosphane ligand. NMR studies reveal that the NHP-AuX2 pairs persist in solution but are kinetically labile and readily undergo halide scrambling. The hydride/fluoride exchange reaction between a secondary phosphane-AuCl complex and [Ph3C][BF4] implies that a gold complex with an intact 2-halogeno-1,3,2-diazaphospholene ligand may be more stable than its phosphenium dihalido-aurate isomer when covalent P-X bonding contributions are strengthened.</p>

Topics

• impedance spectroscopy
• dispersion
• x-ray diffraction
• gold
• density functional theory
• Nuclear Magnetic Resonance spectroscopy