589-63-9Relevant articles and documents
Ligand effects in the stabilization of gold nanoparticles anchored on the surface of graphene: Implications in catalysis
Ventura-Espinosa, David,Martín, Santiago,García, Hermenegildo,Mata, Jose A.
, p. 113 - 120 (2021)
Gold nanoparticles (Au NPs) functionalized with N-heterocyclic carbene (NHC) ligands immobilized onto graphene are obtained via spontaneous decomposition of well-defined gold-NHC complexes by reduced graphene oxide (rGO) without reducing agents. NHC ligands are responsible for the formation of air-stable, crystalline and small (3.0–4-0 nm) Au NPs homogeneously distributed on the surface of graphene. The catalytic properties of three Au NPs functionalized with different ligands were tested in two benchmark reactions (hydration of alkynes and intramolecular hydroamination of alkynes). The results reveal a pronounced ligand effect on the stability of Au NPs on graphene, by acting as a bridge between them. The Au NPs functionalized with a NHC ligand lacking a polyaromatic group or having a naphthyl tag displayed limited stability and fast deactivation in the first run. On the contrary, the Au NPs functionalized with a NHC ligand containing a pyrenyl handle showed superior catalytic activity and can be recycled at least ten times. The particle size of the Au NPs is preserved after the recycling process indicating a high stability. These results illustrate the use of purposely designed ligands having affinity for both Au NPs and graphene to increase the stability of the hybrid catalyst.
Ncube et al.
, p. 2345 (1978)
The effects of metals and ligands on the oxidation of n-octane using iridium and rhodium “PNP” aminodiphosphine complexes
Naicker, Dunesha,Alapour, Saba,Friedrich, Holger B
, p. 282 - 289 (2020/12/01)
Ir and Rh “PNP” complexes with different ligands are utilized for the oxidation of n-octane. Based on the obtained conversion, selectivity, and the characterized recovered catalysts, it is found that the combination of Ir and the studied ligands does not promote the redox mechanism that is known to result in selective formation of oxo and peroxo compounds [desired species for C(1) activation]. Instead, they support a deeper oxidation mechanism, and thus higher selectivity for ketones and acids is obtained. In contrast, these ligands seem to tune the electron density around the Rh (in the Rh-PNP complexes), and thus result in a higher n-octane conversion and improved selectivity for the C(1) activated products, with minimized deeper oxidation, in comparison to Ir-PNP catalysts.
Efficient and region-selective conversion of octanes to epoxides under ambient conditions: Performance of tri-copper catalyst, [Cu3I(L)]+1 (L=7-N-Etppz)
Krupadam, Reddithota J.,Nagababu, Penumaka,Paul, Perala Sudheer,Reddy, Thatiparthi Byragi
, p. 742 - 745 (2021/09/28)
In this paper, is described the conversion of the octane group of hydrocarbons into industrially important epoxides using tri-copper catalyst, [Cu3I(L)]+1 (L=7-N-Etppz). The role of hydrogen peroxide as a sacrificial oxygen donor during catalytic conversion to epoxides has been investigated. The performance of the catalyst has been evaluated in terms of turnover numbers (TON) and turnover frequencies (TOF) reported in this article.