Ultra‐small sugar‐substituted N‐heterocyclic carbene‐protected palladium nanoparticles and catalytic activity. (14th April 2019)

• Record Type: Journal Article
• Authors: Zhou, Zhonggao; Li, Mei; Liu, Guangsheng; Xu, Guohai; Xue, Jun
• Is Part Of: Applied organometallic chemistry. Volume 33:Number 7(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-04-14
• Subjects: ligand exchange -- palladium nanoparticle -- sugar‐substituted NHCs -- ultra‐small -- water‐soluble; Organometallic chemistry -- Periodicals; Organometallic compounds -- Periodicals; 547.05
• DOI: 10.1002/aoc.4942
• Languages: English
• ISSNs: 0268-2605

Abstract

Abstract : Ultra‐small Pd nanoparticles (UNPs) represent a distinctive type of nanomaterial making them very attractive for a range of applications. Herein, chiral sugar‐substituted N‐heterocyclic carbenes (NHCs) with various lengths of alkyl chain (sugar‐NHCs‐ n C n H2 n +1 ) were first used to prepare water‐soluble Pd@NHCs‐sugar UNPs via an efficient ligand‐exchange strategy, which can be handled under air and are stable over 10 months. The Pd@NHCs‐sugar UNPs were highly monodisperse, with tunable core diameters from 1.7 to 2.1 nm, and an effect of the particle size on the N‐substituted aliphatic chains was observed. To investigate the accessibility of the surface, the Pd@NHCs‐sugar UNPs were studied as catalysts for C–C coupling reaction in eco‐friendly ethanol aqueous solution without any precipitation of metallic Pd. The presence of the longest aliphatic group in the Pd@NHCs‐sugar UNPs imparts to them the highest catalyst activity (turnover number and turnover frequency up to 196 000 and 3 920 000 h −1 ). Abstract : An efficient ligand‐exchange procedure for the synthesis of ultra‐small, water‐soluble, stable chiral sugar‐based NHC‐protected Pd nanoparticles (Pd@NHCs‐sugar UNPs) with sizes ranging from 1.7 to 2.1 nm has been established. The Pd@NHCs‐sugar UNPs had greatly improved the catalytic activity with the best turnover number and turnover frequency up to 196 000 and 3 920 000 h −1 .