Stability and trans Influence in Fluorinated Gold(I) Coordination Compounds

Abstract

We examined the Au–P and Au–X chemical bonding scenario throughout the series of compounds of the general formula [AuX(LP)] wherein LP is triphenylphosphine or a fluorinated phosphine [PPhF = P(C6H5)2(C6F5) 1, P(C6H5)(C6F5)2 2 and P(C6F5)3 3] and X is chloride or a fluorinated thiolate [SRF = SCF3 a, SCH2CF3 b, SC6F5 c, SC6F4(CF3)‐4 d]. We found that the increase of the fluorination degree or the replacement of Cl– by a –SRF ligand decreases the stability of the compound. Furthermore, this substitution shifts the 31P‐NMR signals to low field, which indicates differences in the electronegativity of the phosphorus due to the distinct trans influences of the Cl– and –SRF species. These effects correlate with the charge of the gold atom coordinated to phosphorus. Our investigation shows the high potential of fluorination as a strategy for the modulation of the properties of gold compounds, for example in catalysis, and the applicability of quantum chemical topology studies in the explanation of these features.

Recent Advances in Gold(III) Chemistry: Structure, Bonding, Reactivity, and Role in Homogeneous Catalysis

“…One such study on the ligand exchange kinetics of gold­(III) complexes demonstrated the strong trans -effect exerted by σ-donating aryl anions, which facilitates the displacement of the chloride ligands trans to phenyl by methanol and its subsequent substitution by nucleophiles in the sequence Nu = NO 2 < Cl < Br < N 3 ≈ I < NCS . Recent years have seen a resurgence of interest in such ligand effects in gold­(I) chemistry, − since they underpin the behavior of these complexes in catalysis, notably their propensity to undergo oxidative addition . Ligands L that exert a strong ground state trans -influence in complexes of type trans -LAu­(Y) 2 X lead to the elongation/weakening of the Au-X bond …”

Comparative Analysis of the Donor Properties of Isomeric Pyrrolyl Phosphine Ligands

“…The M–P coupling constants and available bond lengths for this series track with those seen in the trans -( L ) 2 Rh­(CO)Cl series, but crystallographic data concerning the Pt–Cl bond for all complexes were not obtained. Fortunately, a trans influence series has been previously examined with linear gold­(I) complexes, which has been validated both experimentally , and computationally, , encouraging us to compare our own series of gold complexes (Figure ). The Au–Cl bonds of ( L2 )­AuCl and ( L3 )­AuCl are comparable in length [2.243(9) and 2.233(2) Å, respectively] while that of ( L1 )­AuCl (2.220(1) Å) is shorter.…”

Directing the Crystal Packing in Triphenylphosphine Gold(I) Thiolates by Ligand Fluorination

“…Silver­(I) trifluoromethylthiolate, obtained as described in ref , was used in the synthesis of 12 because of the instability of the lead analogue. The compound [AuCl­(PPh 3 )] was obtained by the direct reaction of K­[AuCl 4 ] with PPh 3 as reported by Fackler et al The synthesis and characterization of compounds 1 , 3 , 11 , and 12 were previously reported. , The syntheses of all the new compounds were carried in a similar manner, thus only the synthesis of 2 is described in detail.…”