Hydrogen Bonding in Platinum Indolylphosphine Polyfluorido and Fluorido Complexes

The reaction of the Pt complexes cis‐[Pt(CH(3))(Ar){Ph(2)P(Ind)}(2)] (Ind=2‐(3‐methyl)indolyl, Ar=4‐tBuC(6)H(4) (1 a)(,) 4‐CH(3)C(6)H(4) (1 b), Ph (1 c), 4‐FC(6)H(4) (1 d), 4‐ClC(6)H(4) (1 e), 4‐CF(3)C(6)H(4) (1 f)) with HF afforded the polyfluorido complexes trans‐[Pt(F(HF)(2))(Ar){Ph(2)P(Ind)}(2)] 2 a–f, which can be converted into the fluoride derivatives trans‐[Pt(F)(Ar){Ph(2)P(Ind)}(2)] (3 a–f) by treatment with CsF. The compounds 2 a–f and 3 a–f were characterised thoroughly by multinuclear NMR spectroscopy. The data reveal hydrogen bonding of the fluorido ligand with HF molecules and the indolylphosphine ligand. Polyfluorido complexes 2 a–f show larger |(1) J(F,Pt)|, but lower (1) J(H,F) coupling constants when compared to the fluorido complexes 3 a–f. Decreasing (1) J(P,Pt) coupling constants in 2 a–f and 3 a–f suggest a cis influence of the aryl ligands in the following order: 4‐tBuC(6)H(4) (a) ≈4‐CH(3)C(6)H(4) (b)<Ph (c)≪4‐FC(6)H(4) (d)<4‐ClC(6)H(4) (e)<4‐CF(3)C(6)H(4) (f). In addition, the larger cis influence of aryl ligands bearing electron‐withdrawing groups in the para position correlates with decreasing magnitudes of |(1) J(F,Pt)| coupling constants. The interpretation of the experimental data was supported by quantum‐chemical DFT calculations.