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Au19 nanocluster featuring a V-shaped alkynyl-gold motif
Xian-Kai Wan1, Qing Tang, Shang-Fu Yuan
1State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University , Xiamen, Fujian 361005, P. R. China.
Abstract:
A novel Au19 nanocluster with a composition of [Au19(PhC≡C)9(Hdppa)3](SbF6)2 was synthesized (Hdppa = N,N-bis(diphenylphosphino)amine). Single crystal X-ray structural analysis reveals that the cluster comprises a centered icosahedral Au13 core hugged by three V-shaped PhC≡C-Au-C≡C(Ph)-Au-C≡CPh motifs. Such motif is observed for the first time in an alkynyl-protected gold nanocluster. The Au19 cluster shows two main optical-absorption bands at 1.25 and 2.25 eV, confirmed by time-dependent density functional theory. Orbital analysis indicates that PhC≡C- groups can actively participate in the frontier orbitals of the whole cluster. The new Au19 cluster and the novel alkynyl-gold motif open the door to understanding the alkynyl-gold interface and discovering many potential members of this new class of gold clusters.
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