Cobaltocene Reduction of Cu and Ag Salts and Catalytic Behavior of the Nanoparticles Formed

Abstract

The modes of generation of nanoparticles (NPs) are of great interest for multiple applications in catalysis, optics, sensing, and nanomedicine. Here, fast reduction of CuSO4·5H2O and Ag salts by commercial cobaltocene yields small, stable, water-soluble Cu and Ag NPs with a narrow size distribution without any other ligand or support. The variation of the Ag salt counteranion (NO3 –, F–, BF4 –) strongly influences both the plasmonic absorption of the AgNPs synthesized in this way and the high apparent rate constant of the AgNP-catalyzed reduction of 4-nitrophenol by NaBH4, showing that the precursor counteranion binds to the AgNP surface. The CuNPs synthesized from CuSO4 and cobaltocene are a recyclable catalyst for the Cu-catalyzed alkyne–azide cycloaddition reaction in water extended to various azides and alkynes, including functionalization of compounds of biomedical interest. Both CuNP and AgNP catalytic activities are also very promising signs for further extension to a variety of other truly efficient metal-NP-catalyzed reactions.

Synthesis, structures, photophysical properties, and catalytic characteristics of 2,9‐dimesityl‐1,10‐phenanthroline (dmesp) transition metal complexes

“…1 H NMR (400 MHz, CDCl 3 ) δ 7.79 (d, J = 7.6 Hz, 2H), 7.67 (s, 1H), 7.40–7.34 (m, 5H), 7.31–7.28 (m, 3H), 5.54 (s, 2H). These spectroscopic data are in accord with the literature …”

High catalytic activity of Rh nanoparticles generated from cobaltocene and RhCl3 in aqueous solution

“…This indicated that the plasmon band of the AgNPs was sensitive to the counter anion coordinated to the AgNP surface. 27 Thus the anions Clare weak L (2-electron) ligands for such M 0 NP surfaces ( Fig. 3).…”

“…It is likely that the formation of these RhNP nanocrystals results from supramolecular electrostatic assembly involving interaction between the polyanionic RhNPs via the cobalticinium linkers. The RhNPs are compared to other MNPs 26,27 using their catalytic efficiency in the reduction by NaBH4 of the pollutant 4-nitrophenol (4-NP) to the dye 4-aminophenol (4-AP). See SI.…”

“…Here we report the synthesis of RhNPs generated by reduction of RhCl3 in water using the commercial reducing agent cobaltocene 21 in THF in stoichiometric amount. Cobaltocene is a strong reducing agent 22,23 that has recently been used for the reduction of graphene oxide, 24 the generation of H2 25 and the reduction of Au, 26 Pd, 26 Cu 27 and Ag 27 salts to metal NPs. It is an electron-reservoir complex, 28,29 i.e.…”

Living ROMP Synthesis and Redox Properties of Triblock Metallocopolymers Containing Side‐Chain Iron and Cobalt Sandwich Complexes

“…This broad interest is due to the rich Fc chemistry and reversible redox properties at mild potential that lead to functional applications of sophisticated architectures . Substituted cobalticenium salts have distinct basic chemical properties from those of ferrocene due to the charge difference and also allow easy incorporation into polymers via carbonyl chloride or ethynyl side groups . On the other hand, permethylated ring sandwich complexes such as 1,2,3,4,5‐pentamethylferrocenyl (Fc*) and cationic organoiron complex [Fe(η 5 ‐C 5 H 4 ‐)(η 6 ‐C 6 Me 6 )][PF 6 ] (FbX) have seldom been incorporated into organic polymeric frameworks owing to the challenge in their synthesis, although Abd‐El‐Aziz has already thoroughly investigated metallomacromolecules containing [Fe(η 5 ‐C 5 H 5 )(η 6 ‐arene)][PF 6 ] units with p ‐substituted arenes.…”