A highly active multi‐usable palladium pyridylfluorene film‐based catalyst for C–C cross‐coupling reactions. (14th October 2015)

• Record Type: Journal Article
• Authors: Zhao, Xiuhua; Zhao, Yayun; Zhang, Jie; Li, Xing
• Is Part Of: Applied organometallic chemistry. Volume 29:Number 12(2015:Dec.)
• Page Start: 840
• Page End: 845
• Publication Date: 2015-10-14
• Subjects: Pd(II) complex -- fluorene pyridine -- multilayer film -- Suzuki–Miyaura reaction -- Mizoroki–Heck reaction; Organometallic chemistry -- Periodicals; Organometallic compounds -- Periodicals; 547.05
• DOI: 10.1002/aoc.3391
• Languages: English
• ISSNs: 0268-2605

Abstract

Abstract : The two terminal pyridyl nitrogen atoms of 2, 7‐bis(4‐pyridyl)fluorene (1 ) were coordinated to Pd(II) ions to give self‐assembled, multilayer films using the layer‐by‐layer (LbL) method. The films were prepared by alternately dipping the substrate, pre‐coated with a polyethyleneimine layer, in aqueous solutions of PdCl2 and ethanol solutions of1 . The resulting films were characterized using UV–visible absorption spectroscopy, atomic force microscopy (AFM), X‐ray photoelectron spectroscopy, scanningelectron microscopy (SEM) andinductively coupled plasma atomic emission spectroscopy (ICP‐AES). UV–visible spectra and SEM images show almost uniform growth of the film in a near ideal LbL manner. AFM images show that nanostructured aggregates of Pd(II) complexes form on the surface. With an increase in the number of Pd(II)/1 bilayers, more particulate aggregates are distributed on the surface. When released from the substrate, the Pd(II) complex nanostructure shows highcatalytic activity forSuzuki–Miyaura and Mizoroki–Heckcross‐coupling reactions . The catalyst loading is as low as 9.1 × 10 −3 mol% Pd, as measured using ICP‐AES, and high turnover numbers of up to 1.08 × 10 4 are obtained. Copyright © 2015 John Wiley & Sons, Ltd. Abstract : Polyethyleneimine–(PdCl2 /1 ) n (1 = 2, 7‐bis(4‐pyridyl)fluorene) films were used as catalyst reservoirs for Suzuki–Miyaura and Mizoroki–Heck reactions. The catalyst loading in the reactions can be controlled at the parts per million level and is tunable by altering the release time. The films can be reused for five times giving yields greater than 82%.