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A highly active multi‐usable palladium pyridylfluorene film‐based catalyst for C–C cross‐coupling reactions
Author(s) -
Zhao Xiuhua,
Zhao Yayun,
Zhang Jie,
Li Xing
Publication year - 2015
Publication title -
applied organometallic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 71
eISSN - 1099-0739
pISSN - 0268-2605
DOI - 10.1002/aoc.3391
Subject(s) - chemistry , x ray photoelectron spectroscopy , catalysis , substrate (aquarium) , palladium , heck reaction , absorption spectroscopy , scanning electron microscope , spectroscopy , transmission electron microscopy , suzuki reaction , coupling reaction , analytical chemistry (journal) , chemical engineering , organic chemistry , materials science , composite material , oceanography , physics , quantum mechanics , engineering , geology
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 PdCl 2 and ethanol solutions of 1 . The resulting films were characterized using UV–visible absorption spectroscopy, atomic force microscopy (AFM), X‐ray photoelectron spectroscopy , scanning electron microscopy (SEM) and inductively 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 high catalytic activity for Suzuki–Miyaura and Mizoroki–Heck cross‐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.