Coordination Chemistry of Bis‐Cyclic Alkyl(Amino) Carbene (cAAC)‐Supported Di‐Phosphorus (P2): An Efficient Route to Donor Base‐Stabilized Elusive Di‐Phosphorus‐Monoxide(P2O)‐Gold Complex

Abstract

AbstractThe stability and reactivity studies of heavier di‐atomic group‐15 congeners of alkynes, e. g., the di‐phosphorus (P≡P) compounds have been the topic of huge interest because of their contrasting transient properties and lower stability compared to those of the stable molecular di‐nitrogen (N≡N). Herein, we depict the reactivity studies of the bis‐cAAC‐stabilized di‐phosphorus (P2) having an inversely polarized phosphaalkene nature featuring the C=P double bonds with Au(I)Cl. Both the mono‐, and the di‐aurated phosphaalkenes with the formulae [(Me2‐cAAC=P)2(AuCl)] (2), and [(Me2‐cAAC=P)2(AuCl)2] (3), respectively have been isolated in the solid state. Moreover, for the first time, we have been able to isolate the cAAC‐stabilized tetra‐aurated elusive di‐phosphorus‐monoxide (P2O) with the formula [(Cy‐cAAC=P)−O−(P=cAAC−Cy)(AuCl)4] (5) in presence of oxygen. Complexes 2–3, 5 have been structurally characterized by single crystal X‐ray diffraction, and further studied by NMR spectroscopy. Our findings reveal significant elongation of the CcAAC−P bonds in 2–3, 5, and the presence of aurophilic interaction in 5. Quantum chemical calculations, including density functional theory (DFT), and energy decomposition analysis coupled with natural orbitals for chemical valence (EDA‐NOCV) have been performed to study the electron densities distribution and nature of bonding in 2–3, 5.