摘要
By the strategy of replacing the H_(2)O ligands in the“paddle wheel”shaped copper dimer Cu_(2)(OAc)_(4)(H_(2)O)_(2)with polyoxometalate(POM)[H_(2)W_(12)O_(40)]_(6)−{W_(12)O_(40)}pro-ligands,a novel nano porous 2D network{[Cu_(2)(OAc)_(4)]_(2)(W_(12)O_(40))}_(n)was obtained.The POM-copper centered redox reactions and stability of the compound were studied by cyclic voltammetry.Furthermore,the compound was found to be a superefficient homogeneous catalyst(almost 100%conversion)in homo-coupling of terminal alkynes compared with its components and physical mixture under mild conditions with low amounts.The in situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy(DRIFTS)results clearly show the changes of alkyne substances in the catalytic process and the X-ray photoelectron spectroscopy(XPS)results reveal the electron transfer from{W_(12)O_(40)}to Cu(Ⅱ)to promote the C-H activation step during the homo-coupling of terminal alkynes.The synergistic Cu(Ⅱ)-POM catalytic mechanism was proposed.
基金
support of this work from the National Natural Science Foundation of China(NSFC 21801226)
the Natural Science Foundation of Zhejiang Province(LY20B010002 and LQ22B010002)
the Zhejiang Normal University Fund.
