Electrochemical activation of reactions involving organometallic compounds

Abstract

A magnetization study on the superconducting filled skutterudite La 0.8 Rh 4 P 12 has revealed the lower critical field H C1 (0) of 71(2) Oe and the upper critical field H C2 (0) of 126 (7) kOe. Using these values, the coherent length ξ(0), penetration depth λ(0) and Ginzburg-Landau parameter κ(0) were determined to be 5.1(1) nm, 3.1(2) × 10 2 nm and 60(3), respectively. The estimated critical current was 18.4 kA cm −2 at 4.2 K and 0 kOe using the Bean model.

Ligand Redox Non‐Innocence in Transition‐Metal σ‐Alkynyl and Related Complexes

“…In an early example of redox non-innocence in a metal alkyne complex, one-electron oxidation of the anion derived from the deprotonation of [ 8 ] is thought to give initially the expected alkyne complex [{Co 2 (CO) 6 }-{μ-PhC 2 ML}] (L = PPh 3 , CϵCPh), which converts by an unspecified mechanism into the C-C oxidatively coupled product [{Co 2 (CO) 6 } 2 (μ-PhC 2 C 2 Ph)]. [95] Similarly, reactions of 1-iodo-2-ferrocenylacetylene (FcCϵCI) with excess [Co 2 (CO) 8 ] give [{Co 2 (CO) 6 } 2 (μ-FcC 2 C 2 Fc)], presumably accompanied by the formation of I 2 .…”

“…[5][6][7] Electrochemical activation of metal complexes to promote chemical reactions is also known, but less widely employed as a tool in synthetic chemistry. [8] However, descriptions of redox reactions in terms of a change in the population of metal-centred orbitals are now recognised as being overly simplistic, particularly for those complexes featuring π-donor or -acceptor ligands in which the frontier orbitals that support the unpaired electron have appreciable metal-ligand to ligand character. [9] Thus, in the broadest possible terms, the redox chemistry of transitionmetal (organometallic) σ-alkynyl systems {L n M}-CϵCR can be interpreted in terms of either changes in the metal oxidation state or the redox ligand non-innocence of the alkynyl ligand ( Figure 1).…”

Comparison of the Thermal and Reductive Decarbonylation of a Rhodium Trifluoroacetyl Diphosphine Complex

“…We have a longstanding interest in organometallic reactions initiated or catalyzed by electron transfer, and it occurred to us that the decarbonylation of rhodium acyl complexes containing dppp might be amenable to study. In particular, we were curious to see whether these complexes could undergo electron transfer chain catalyzed (ETC − ) decarbonylation. The reaction might be expected to proceed as Rh false( dppp false) false( COR false) normalX 2 + normale − → false[ Rh false( dppp false) false( COR false) normalX 2 false] − false[ Rh false( dppp false) false( COR false) normalX 2 false] − → false[ Rh false( dppp false) false( CO false) false( normalR false) normalX 2 false] − false[ Rh false( dppp false) false( CO false) false( normalR false) normalX 2 false] − + Rh false( dppp false) false( COR false) normalX 2 → Rh false( dppp false) false( CO false) false( normalR false) normalX 2 + false[ …”

CuI complexes with 2,2′-biquinolyl-containing polymeric ligands as electrocatalysts for the oxidative coupling of alkynes in the presence of dioxygen

“…Furthermore, electrochemical activation allows per forming reactions under mild conditions, at room temperature and atmospheric pressure, which often ensures high selectivity of a process. 13 Recently, 14 we have elaborated an electrochemical approach using the sacrificial anode technique to the new polynuclear Cu I complexes with polymeric ligands based on polyamido acids (PA) with biquinolyl (biQ) fragments in the polymer backbone. The presence of the polymeric ligand, as well as the presence of the excess of Cu I ions (which is easily accessible using instrumental control by optimization of the current and potential values) allow one to obtain coordinatively unsaturated Cu I complexes with only one biQ fragment in the Cu I coordination envi ronment.…”