Electron Flow in Large Metallomacromolecules and Electronic Switching of Nanoparticle Stabilization: Click Ferrocenyl Dentromers that Reduce AuIII to Au Nanoparticles. Issue 48 (18th July 2018)

• Record Type: Journal Article
• Authors: Wang, Qi; Fu, Fangyu; Martinez‐Villacorta, Angel M.; Moya, Sergio; Salmon, Lionel; Vax, Amélie; Hunel, Julien; Ruiz, Jaime; Astruc, Didier
• Is Part Of: Chemistry. Volume 24:Issue 48(2018)
• Page Start: 12686
• Page End: 12694
• Publication Date: 2018-07-18
• Subjects: dendrimers -- electron reservoir -- nanoparticles -- redox switch -- sandwich complex; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201802289
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Click ferrocenyl‐terminal dentromers, a family of arene‐cored dendrimers with triple branching (9‐Fc, 27‐Fc, 81‐Fc, and243‐Fc ), reduce Au III to ferricinium dentromer‐stabilized Au nanoparticles (AuNPs). Cyclic voltammetry studies in CH2 Cl2 show reversible CV waves with some adsorption for the243‐Fc dentromer and the number of redox groups found, 255±25, by using the Bard–Anson method, is close to the theoretical number of 243. The dentromers reduce aqueous HAuCl4 to water‐soluble ferricinium chloride dentromer‐stabilized AuNPs with core sizes between 30 and 47 nm. These triazolylferricinium dentromer‐stabilized AuNPs are reduced by cobaltocene to cobalticinium chloride and ferrocene dentromer weakly stabilized AuNPs together with a redshift of the AuNP plasmon. The weakness of the AuNP stabilization is characterized by dentromer extraction with CH2 Cl2 along with irreversible AuNP agglomeration for the 9, 27, and 81‐ferrocenyl dentromer, with only the 243‐ferrocenyl dentromer‐AuNP withstanding this process. Altogether, this demonstrates the electronic switching of the dentromer‐mediated AuNP stabilization. Abstract : Generation gap : Au nanoparticle stabilization by dentromers, arene‐cored dendrimers with triple branching, can be switched in metallomacromolecules with large electron flows by using redox reagents. The switch the between strong and weak stabilization depends on the electrostatic factor and dentromer generation.