Copper(I) and Gold(I) Complexes of Aminofunctionalized Phosphinines: Synthesis and Structural Characterization

Abstract

Dedicated to Prof. Dr. Sjoerd Harder on the occasion of his 60 th birthday A series of novel 3-N,N-dimethylaminofunctionalized phosphinines were synthesized and structurally characterized. DFT calculations showed that these aromatic phosphorus heterocycles possess stronger π-donor and σ-donor properties compared to the parent phosphinine C 5 H 5 P. With CuBr • SMe 2 , the corresponding complexes of the type [(phosphinine) 2 CuBr] 2 are formed, which show the classical terminal σ-coordination mode of the phosphorus donor towards the Cu(I) center. Upon reaction with AuCl • SMe 2 , mononuclear phosphinine-Au(I)Cl complexes could be obtained and crystallographically characterized. Moreover, the presence of a SiMe 3 -group and a donorfunctionality provide the possibility for post-synthetic ligand modifications. With CuCl • SMe 2 the phosphinine-based hydrochloride salts forms a rare Cu(I) complex with a Cu 4 Cl 4core, that contains two pairs of differently coordinating phosphinine ligands.

The case of a μ2-P aromatic phosphinine as a 4-electron donor forming σ- and π-three–center-two-electron bonds

“…This coordination mode differs significantly from previously reported μ 2 -P phosphinine with two σ-lone pairs as a 4e donor. 4 a , e ,7,10,14 NBO analyses indicate that there are negligible π-type interactions between η 1 -phosphinine and the metal, but reveal relatively strong π-type interactions in μ 2 -phosphinine complexes. In addition, stronger π-type interactions are found to induce longer P–C bonds and larger Δ coord in μ 2 -phosphinine.…”

“…However, μ 2 -P phosphinine with electron donating substituents is prone to donate two lone pairs (type IV , Fig. 1b), 4 a , e ,7,10,14 and may also donate one lone pair and accept π-back donation (type V , Fig. 1b).…”