Organomercury compounds. Part I. Mercury pentafluorobenzoates and their decarboxylation to pentafluorophenylmercury compounds

Abstract

The preparations of some mercury derivatives of pentafluorobenzoic acid and their decarboxylation to give pentafluorophenylmercury compounds are described. Mercuric pentafluorobenzoate and C,F,CO,HgR ( R = Ph, p-MeCGH4, or p-MeOC,H,) have been prepared by reaction of pentafluorobenzoic acid with mercuric acetate and R HgOAc, respectively, and methylmercuric pentafluorobenzoate has been made from methylmercuric iodide and silver pentafluorobenzoate. The complexes (C6F5C0,)zHgL ( L = 2,2'-bipyridyl, 1 ,I O-phenanthroline, or 1.2bisdiphenylphosphinoethane) were obtained from reactions of these ligands with mercuric pentafluorobenzoate.The pentafluorobenzoates are monomeric and have low conductances in acetone. Conductances of representative compounds in methanol and pyridine have also been measured. Infrared data suggest that the compounds may contain unidentate pentafluorobenzoate groups.Mercuric pentafluorobenzoate and 2,2'-bipyridylmercuric pentafluorobenzoate decarboxylate a t their melting points and the other pentafluorobenzoates decarboxylate on heating in dry pyridine to give the corresponding pentafluorophenylmercury compounds. In acetone and benzene, the complexes (C6F5),HgL dissociate into L and and bispentafluorophenylmercury.

The Gold(I)‐Catalysed Protodecarboxylation Mechanism

“…A similar equilibrium had been observed by Sheppard when studying the carboxyl displacement from [Cu(OAc)] to [Cu(O 2 CR)] (R=C 6 F 5 , o ‐NO 2 C 6 H 4 , CClF 2 and CCF 3 ) 10. In contrast, the RC(O)OHg bond was found to be resistant to AcOH 15. Interestingly, repeating the reaction using 2‐nitrobenzoic acid ( 2 b ) with 1 a led to 90 % conversion to the corresponding gold(I) 2‐nitrobenzoate intermediate ( 4 b ).…”

“…[10] In contrast, the RC(O)OÀHg bond was found to be resistant to AcOH. [15] Interestingly, repeating the reaction using 2-nitrobenzoic acid (2 b) with 1 a led to 90 % conversion to the corresponding gold(I) 2-nitrobenzoate intermediate (4 b). Ultimately, these data suggested that the displacement of the equilibrium is likely pK a -dependent with respect to the benzoic acid employed.…”

Synthesis and Hydrolysis of Uranyl, Neptunyl, and Plutonyl Gas-Phase Complexes Exhibiting Discrete Actinide–Carbon Bonds

“…1680 cm −1 is characteristic of an asymmetric O−C−O stretching mode of a monodentate ligand. Variable denticities of carboxylate ligands to different metallic centers have been previously reported; 15,66 uranyl complexes having variable denticity have been reported by Groenewold and collaborators. 67 The peak at ca.…”

“…Decarboxylation reactions of condensed-phase metal carboxylates is a well-established method of synthesis of organometallic compounds. − Deacon and collaborators have synthesized and studied the structural and vibrational properties of uranyl pentafluorobenzoate and its coordination derivatives with 2,2′-bipyridyl, triphenylphosphine oxide, and triphenylarsine oxide. This report includes thermal decomposition studies of the same solution complexes, which however do not yield UO 2 (C 6 F 5 ) 2 derivatives by decarboxylation …”

Organometallic Compounds

“…Unsymmetrical phenylpentafluorophenyl and methylpentafluorophenyl compounds are obtained from the appropriate mercury(II) halide [45], or by decarboxylation procedures [69], and these mixed derivatives are particularly susceptible to attack. Unsymmetrical phenylpentafluorophenyl and methylpentafluorophenyl compounds are obtained from the appropriate mercury(II) halide [45], or by decarboxylation procedures [69], and these mixed derivatives are particularly susceptible to attack.…”