Structural studies of steric effects in phosphine complexes. 10. Crystal and molecular structure of bis(trimesitylphosphine)silver(I) hexafluorophosphate

Abstract

The crystal and molecular structure of bis(trimesitylphosphine)silver(I) hexafluorophosphate [Ag(P(mesityl)3)2]+PF6" have been determined. Crystals are trigonal, space group 3,21 (D4 5No. 152), with a = 15.378 (2) A, c = 19.945 (4) A, and 3 formula units in the unit cell. The structure was solved by the heavy-atom method and refined by full-matrix least-squares calculations with three-dimensional diffractometer data to a final discrepancy index RF = 0.070 for 922 reflections with I > 3 ( ). This is the first structure determination of a two-coordinate silver cation with phosphine ligands. Both cation and anion lie on separate crystallographic twofold axes, the anion being additionally disordered over two sites. In the cation, the bulk of the P(mes)3 (mes = mesityl) ligands ensures an almost linear P-Ag-P moiety (179.4°), a regular propeller conformation with dihedral angles between the Ag-P-C and mesityl planes in the 45-51 °range, a relatively long Ag-P distance 2.461 (6) Á and irregular angles at phosphorus (Ag-P-C 107.3-109.3 (9)°, C-P-C 108-113(1)°). Cone angle calculations are made for the P(mes)3 ligand ( = 203°).

Synthesis and Characterization of Linear Tetranuclear Silver(I) Complexes Bridged by Tetraphosphane Ligands

“…When dpmppm was treated with 2 equiv. AgOTf in the presence of isocyanides (RNC), linear tetrasilver(I) complexes [Ag 4 (OTf) 3 …”

“…[Ag 4 (OTf) 3 [Ag 4 (OTf) 3 (dpmppm) 2 (XylNC) 2 ](OTf)·CH 2 Cl 2 (2a·CH 2 Cl 2 ): To a solution of dpmppm (50 mg, 8.0 ϫ 10 -2 mmol) in dichloromethane (7.5 mL) was added AgOTf (40 mg, 0.16 mmol) in the presence of XylNC (78 mg, 0.59 mmol), and the reaction mixture was stirred at room temperature for 12 h to give a pale yellow solution. The solution was concentrated and diethyl ether was slowly added to the solution to afford colorless crystals of 2a·CH 2 Cl 2 .…”

“…[1,2] In particular, phosphane ligands are shown to influence the geometrical structures of silver(I) centers, from two-coordinate linear structures with bulky phosphanes [3] to four-coordinate tetrahedral with sterically less-hindered phosphanes. [4] Bidentate phosphane ligands are also able to have an effect on dinuclear Ag I structures, depending on the length of the linker chains between the two phosphorus atoms; diphosphanes with longer methylene chains form the dinuclear complexes [Ag 2 (µ-X) 2 (µ-diphosphane) 2 ], in which the silver(I) ions adopt a four-coordinate tetrahedral geometry, [5] and, in contrast, diphosphanes bridged by a methylene or an amide linker give the complexes [Ag 2 (µ-diphosphane) 2 ]-X 2 and [Ag 2 X 2 (µ-diphosphane) 2 ], in which the silver(I) ions are located in a two-coordinate linear and a three-coordinate T-shape geometry, respectively.…”

“…[4] Bidentate phosphane ligands are also able to have an effect on dinuclear Ag I structures, depending on the length of the linker chains between the two phosphorus atoms; diphosphanes with longer methylene chains form the dinuclear complexes [Ag 2 (µ-X) 2 (µ-diphosphane) 2 ], in which the silver(I) ions adopt a four-coordinate tetrahedral geometry, [5] and, in contrast, diphosphanes bridged by a methylene or an amide linker give the complexes [Ag 2 (µ-diphosphane) 2 ]-X 2 and [Ag 2 X 2 (µ-diphosphane) 2 ], in which the silver(I) ions are located in a two-coordinate linear and a three-coordinate T-shape geometry, respectively. [6] In addition, triangular complexes with a {Ag 3 (µ-diphosphane) 3 } 3+ core have also been reported. [7] This flexible coordination behavior of silver(I) ions is regarded as an important factor for their catalytic activities in organic synthesis.…”

A Single-Strand Helical Motif Induced by Self-Assembly of [Ag(TFP)]+ Moieties with Nitrate Anions −31P NMR Spectroscopic and X-ray Crystal Structure Characterization of the Complexes Involved in Equilibrium Reactions of Silver Salts and TFP Ligand

“…Tetranuclear cubane-like compounds [AgPR 3 X] 4 (R ϭ Et or Ph) were isolated when strongly coordinating anions (X Ϫ ) such as Cl Ϫ or Br Ϫ were used, [14,15] [17] [Ag{P(mes) 3 } 2 ]PF 6 (mes ϭ C 6 H 2 Me 3 -2,4,6)}. [18] Moreover, the NO 3…”