Hydrogen Bonding in Platinum Indolylphosphine Polyfluorido and Fluorido Complexes

Abstract

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 j 1 J(F,Pt) j , 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 j 1 J(F,Pt) j coupling constants. The interpretation of the experimental data was supported by quantumchemical DFT calculations.

Organoplatinum‐Bridged Cyclotribenzylene Dimers

“…In solution, binding of CuCl to cis ‐[Pt(dppe)(C 2 Ph) 2 ] for example, had little effect on the 31 P NMR chemical shift (Δ δ =−3 %) and no effect on the alkynyl 13 C NMR chemical shifts; [21a] +FAB mass spectrometry of [Pt( t Bu 2 bipy)(C≡CC 6 H 4 Me) 2 Cu(SCN)] gave the signal corresponding to [M−SCN − ] + [22d] . We note that such a hydrogen bond with a metal‐bound halide has been recently observed in platinum indolylphosphine fluorido and chlorido complexes, with strong deshielding of the hydrogen‐bound N H protons [23] …”

“…[22d] We note that such a hydrogen bond with a metal-bound halide has been recently observed in platinum indolylphosphine fluorido and chlorido complexes, with strong deshielding of the hydrogen-bound NH protons. [23] To test further the hypothesis of copper(I) coordination, the crude product of the reaction of rac-2H with cis-[Pt(PEt 3 ) 2 Cl 2 ] in 2 : 1 ratio in the presence of 21 mol% CuI and excess Et 3 N was, after removal of the volatile species, treated with the stoichiometric amount of NaCN prior to purification by column chromatography on silicagel. Figure S64 compares the 1 H NMR spectra in CDCl 3 of the crude product before and after treatment by NaCN, so that the diastereoisomeric ratio is the same in both samples.…”

Indolyl Phosphine Nickel(II) Fluorido Complexes: Synthesis and Intermediates in Suzuki–Miyaura Cross‐Coupling Reactions

“…The NH groups of the indolyl‐substituted phosphine ligands are orientated in such a way that a N(1)⋅⋅⋅F(1)⋅⋅⋅N(1)’ angle of 109.2(3)° is formed. The F(1)−Ni(1)−P(1)−N(1)’ torsion angle of 32.0(2)° indicates a larger twist of the indolyl substituents compared to the distortion of comparable platinum fluorido complexes bearing indolyl‐substituted phosphine ligands [67] . The position of the nitrogen‐bound hydrogen atoms were located in the Fourier map and fixed at these positions.…”

“…The F(1)À Ni(1)À P(1)À N(1)' torsion angle of 32.0(2)°indicates a larger twist of the indolyl substituents compared to the distortion of comparable platinum fluorido complexes bearing indolyl-substituted phosphine ligands. [67] The position of the nitrogen-bound hydrogen atoms were located in the Fourier map and fixed at these positions. The N(1)•••F(1) atom distance of 2.6457(3) Å is larger than the sum of the van-der-Waals radii of fluorine and nitrogen of 3.02 Å.…”