Synthesis and Properties of Mercury Bis(trifluoromethyl)phosphanides and Their Phosphane Complexes

Abstract

The thermally unstable compounds Hg(CN)P(CF(3))(2) and Hg[P(CF(3))(2)](2) were obtained by reactions of mercury cyanide and bis(trifluoromethyl)phosphane in solution and characterized by multinuclear NMR spectroscopy. An increase in thermal stability is observed when the products form 18 valence electron complexes. The compounds [Hg(P(CF(3))(2))(2)(dppe)] (dppe = 1,2-bis(diphenylphosphanyl)ethane) and [Hg(P(CF(3))(2))(2)(Me(3)P)(2)] have been isolated in almost quantitative yield by reacting [Hg(CN)(2)(dppe)] or [Hg(CN)(2)(Me(3)P)(2)] with HP(CF(3))(2). [Hg(P(CF(3))(2))(2)(dppe)] crystallizes in the triclinic space group P1. The mercury atom is coordinated in a distorted tetrahedral fashion. The Hg-P(CF(3))(2) bonds, ca. 250 pm, are significantly longer than those of the mercury bis(phosphanides) Hg(PR(2))(2) with R = t-Bu, 245 pm, or SiMe(3), 241 pm. These easily accessible compounds [Hg(P(CF(3))(2))(2)(dppe)] and [Hg(P(CF(3))(2))(2)(Me(3)P)(2)] act as nucleophilic bis(trifluoromethyl)phosphane group transfer reagents.

Reactivity of mercury(II) halides with the unsymmetrical phosphorus ylide Ph2PCH2CH2PPh2C(H)C(O)Ph: Crystal structure of {HgI2[PPh2CH2CH2PPh2C(H)C(O)Ph]}n

“…This is corroborated by the absence of any species containing two ligands in the ESI Mass spectra in acetonitrile for both 2 and 3. The absence of 199 Hg satellites in the 31 P NMR spectra of all the complexes can be attributed to the fast exchange of ligand with metal, as noted previously for Hg(II)-phosphine complexes [25,26].…”

Synthesis of the First Chiral Bidendate Bis(trifluoromethyl)phosphane Ligand through Stabilization of the Bis(trifluoromethyl)phosphanide Anion in the Presence of Acetone

“…The C À F activation of the PA C H T U N G T R E N N U N G (CF 3 ) 2 À ion and the resulting chemical behavior [9] are comparable to effects observed for the CF 3 O À ion that are interpreted in terms of negative hyperconjugation. [10] The literature contains different interpretations of hyperconjugation.…”

“…[16] The reduced negative hyperconjugation is accompanied by an increased thermal stability of the PA C H T U N G T R E N N U N G (CF 3 ) 2 À ion in solution, which is based on the formation of dynamic Lewis acid/Lewis base (…”

“…The thermally unstable, neat, colorless liquid (CF 3 ) 2 The Pt II complex was characterized through the mass balance of the reaction, mass spectrometry (characteristic isotopic pattern), and multinuclear NMR spectroscopy. Figure 3 shows the proton-decoupled Although PA C H T U N G T R E N N U N G (CF 3 ) 2 À salts are principally useful reagents in nucleophilic substitutions of alkyl tosylates, [9] we were unable to substitute tosyl groups (OTos) in the less-reactive In contrast, the diiodo derivative 1 a could be transformed into the corresponding bidentate bis(trifluoromethyl)phosphane derivative upon treatment with an excess of [K( [18]crown-6)]PA C H T U N G T R E N N U N G (CF 3 ) 2 in the presence of acetone. The exchange was complete within 72 h at À20 8C.…”

Synthesis of a Functional C2‐Symmetrical Bidentate Diphenylphosphonite DIOP Derivative and Its Conversion into the Corresponding π‐Acidic Bis(pentafluorophenyl) and Bis(p‐tetrafluoropyridyl) Compounds

“…Keywords: chirality · Lewis acids · P ligands · phosA C H T U N G T R E N N U N G phonite · phosphanide analysis of a corresponding tetracarbonyl-molybdenum complex. [4] With the aim of synthesizing a corresponding bis(pentafluorophenyl) derivative we investigated the stabilization of the PA C H T U N G T R E N N U N G (C 6 F 5 ) 2 À ion in the presence of weak Lewis acids, such as Hg 2 + ions, [5] as well as CS 2 . [6] However, all attempts to carry out the desired substitution of iodine by PA C H T U N G T R E N N U N G (C 6 F 5 ) 2 groups have been unsuccessful.…”