Synthesis, characterization and electrochemical investigation of hetaryl chromium(0) aminocarbene complexes

Metelková, Radka; Tobrman, Tomáš; Kvapilová, Hana; Hoskovcová, Irena; Ludvı́k, Jiřı́

doi:10.1016/j.electacta.2012.05.027

Cited by 33 publications

(54 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…the dppe-containing complexes [(CO) 3 [45,46,47,47,52]. Since the oxidation centre for all these Fischer Cr-carbene complexes is mainly located on the Cr-metal centre, it is expected that the electronic influence of the dppe ligand directly attached to the Cr atom will be more pronounced than the influence of the different substituents on the carbene ligand.…”

Section: Cr(o)-cr(i) Oxidationmentioning

confidence: 99%

Fac and mer dppe-substituted Fischer carbene complexes of chromium: X-ray, DFT and electrochemical study

Landman

Liu

Fraser

et al. 2014

Journal of Organometallic Chemistry

View full text Add to dashboard Cite

Section: Cr(o)-cr(i) Oxidationmentioning

confidence: 99%

Fac and mer dppe-substituted Fischer carbene complexes of chromium: X-ray, DFT and electrochemical study

Landman

Liu

Fraser

et al. 2014

Journal of Organometallic Chemistry

View full text Add to dashboard Cite

“…18 In this study the Y substituent was represented by either a furyl ring or a thienyl ring (position 4, Figure 1). In a recent report by Ludvík et al 19 on the electrochemical properties of chromium(0) aminocarbene complexes with heteroaryl carbene substituents, it was found that neither a change in heteroaryl, nor a different position of its attachment (2-position vs. 3-position) had a marked influence on the oxidation behaviour, indicating limited metal-carbene communication. For the reduction, the thienyl and furyl heterocyles showed similar behaviour, but the complexes with heteroaryls attached at the 2-position were more easily reduced than those at the 3-position.…”

mentioning

confidence: 99%

“…46 The opposite order is observed for the reduction of [Cr(CO) 5 {C(N(CH 3 ) 2 )Ar}], the reduction potential of the complex with Ar = thienyl < Ar = furyl. 19 · Alkoxy-vs. aminocarbene (compare 1 and 2 to 3 and 4 or 5 and 6): The reduction potential shifts with more than 500 mV more positive when changing from an amino to an ethoxy group, as the carbene carbon atom becomes more positively charged when bonded to the more electronegative oxygen atom, compared to nitrogen. The alkoxycarbenes are thus reduced more easily than the aminocarbenes, at a less negative potential.…”

mentioning

confidence: 99%

Synthesis, Structure, and Electrochemistry of Fischer Alkoxy- and Aminocarbene Complexes of Tungsten: The Use of DFT To Predict and Understand Oxidation and Reduction Potentials

et al. 2013

View full text Add to dashboard Cite

Reactions of Fischer alkoxycarbene complexes[W(CO) 5 {C(OEt)Ar}], Ar = thienyl (1) or furyl (2), with ethylene diamine lead to the formation of two different reaction products: an aminolysis product (5 or 6) where the ethoxy substituent of the carbene ligand is replaced by the ethylene diamine moiety, as well as a chelated product where aminolysis and substitution of one carbonyl ligand had taken place, yielding 7 or 8. Aminolysis of 1 and 2 with cyclohexyl amine (CHA) produced the aminocarbene complexes 3 (Ar = thienyl) and 4 (Ar = furyl). Complexes 1-8 are electrochemically investigated by means of cyclic voltammetry. The relative shifts in the oxidation and reduction potentials are discussed and related to density functional theory (DFT) calculated energies. DFT calculations further show that the oxidation center is located on the metal and the carbonyl groups, while the reduction center is localized on the carbene moiety and is strongly influenced by the electronic properties of its substituents. Crystal structures of 1-4, 6 and 8 are reported.

show abstract

“…and subsequent substitution of the carbene ligand by a phosphine to yield M(CO) 5 PR' 3 . Phosphines of low nucleophilicity, e.g.…”

mentioning

confidence: 99%

Electrochemical behaviour and structure of novel phosphine- and phosphite-substituted tungsten(0) Fischer carbene complexes

Landman

Pretorius

Fraser

et al. 2014

Electrochimica Acta

View full text Add to dashboard Cite

Dedicated to the memory of Professor Robert Vleggaar is investigated by means of cyclic voltammetry. The complexes all exhibit a twoelectron oxidation process that is W-based and a one-electron reduction that is mainly localized on the carbene ligand. Complexes 1-4 and 9-12 are considerably more difficult to oxidize than 5-8 due to the better π-acceptor ability of the (CO) 4 (PR' 3 ) (R' = Ph or OPh) ligand combination than that of (CO) 3 (dppe). Density functional theory calculations on the neutral, reduced and oxidized complexes confirmed the role of the frontier orbitals in the oxidation and reduction processes and enabled formulation of mathematical relationships that can be used to predict experimental measured potentials. X-ray crystal structures of 2cis, 3 and 5 are discussed.

show abstract

Synthesis, characterization and electrochemical investigation of hetaryl chromium(0) aminocarbene complexes

Cited by 33 publications

References 16 publications

Fac and mer dppe-substituted Fischer carbene complexes of chromium: X-ray, DFT and electrochemical study

Fac and mer dppe-substituted Fischer carbene complexes of chromium: X-ray, DFT and electrochemical study

Synthesis, Structure, and Electrochemistry of Fischer Alkoxy- and Aminocarbene Complexes of Tungsten: The Use of DFT To Predict and Understand Oxidation and Reduction Potentials

Electrochemical behaviour and structure of novel phosphine- and phosphite-substituted tungsten(0) Fischer carbene complexes

Contact Info

Product

Resources

About