Publication

Synthesis and Optical Properties of a Dithiolate/Phosphine-Protected Au28 Nanocluster

​Synthesis and Optical Properties of a Dithiolate/Phosphine-Protected Au28 Nanocluster
Maha A. Aljuhani, Megalamane S. Bootharaju, Lutfan Sinatra, Jean Marie Basset, Omar F. Mohammed, and Osman M. Bakr
J. Phys. Chem. C, Just Accepted Manuscript
Maha A. Aljuhani, Megalamane S. Bootharaju, Lutfan Sinatra, Jean Marie Basset, Omar F. Mohammed, Osman M. Bakr
nanocluster
2017

 

While monothiols and simple phosphines are commonly exploited for size-controlled synthesis of atomically precise gold nanoclusters (NCs), dithiols or dithiol-phosphine combinations are seldom applied. Herein, we used a dithiol (benzene-1,3-dithiol, BDT) and a phosphine (triphenylphosphine, TPP) together as ligands and synthesized an atomically precise gold NC with the formula [Au28(BDT)4(TPP)9]2+. This NC exhibited multiple absorption features and a charge of +2, which are distinctly different from the reported all-thiolated [Au28(SR)20]0 NC (SR: monothiolate). The composition of [Au28(BDT)4(TPP)9]2+ NC was deduced from high-resolution electrospray ionization mass spectrometry (ESI MS) and it was further corroborated by thermogravimetric analysis (TGA). Differential pulse voltammetry (DPV) revealed a HOMO-LUMO gap of 1.27 eV, which is in good agreement with the energy gap of 1.3 eV obtained from its UV-Vis spectrum. The successful synthesis of atomically precise, dithiol-protected Au28 NC would stimulate theoretical and experimental research into bidentate ligands as a new path for expanding the library of different metal NCs, which have so far been dominated by monodentate thiols.

 

DOI: 10.1021/acs.jpcc.6b10205