Reactivity of [{(N3N)W P] towards Gold(I) salts – Synthesis of [{(N3N)W P AuCl] and [{(N3N)W P}2Au][pftb] (pftb = Al(OC(CF3)3)4)

Abstract

The reactivity of the terminal phosphido complex [(N3N)WP] (1) (N3N = tren = N(CH2CH2NSiMe3)3) towards the coinage metal salts [Au(tht)Cl] (tht = tetrahydrothiophene) as well as [Au(MeCN)4]+[pftb]− containing the weakly coordinating anion [Al(OC{CF3)3}4]−(pftb) was investigated. The complexes [{(N3N)WPAuCl] (2) as well as [{(N3N)WP}2Au]+[pftb]− (3) were formed in good yields and were characterized by spectroscopic methods, mass spectrometry and single crystal X-ray diffraction. In the solid state, all complexes present a linear coordination around the gold center but the W-P-Au-P-W unit in 3 is bent. DFT calculations shed light on the electronic structure of these complexes and show that the bending of the W-P-Au-P-W unit is due to the dispersion effects between the Me3Si groups of the tren ligand. The triple bond nature of the W-P bond is preserved in 2 and 3.