Organoimido functionalized trinuclear gold(I) clusters with fluorescent chromophore

Abstract

The post-functionalization of gold nanoclusters with organic molecules into organic–inorganic hybrid functional materials is an efficient approach to develop multifunctional materials. By introducing 1-pyrenamine and 3-aminofluoranthene into [O(AuPPh3)3][BF4] with a covalent bond, two novel organoimido functionalized trinuclear gold nanoclusters [C16H9N(AuPPh3)3][BF4] (Au3–P) and [C6H4–C10H5N(AuPPh3)3][BF4] (Au3–F) have been successfully obtained. Their structures have been determined by electrospray ionization mass spectroscopy (ESI–MS) and single-crystal X-ray diffraction (SC-XRD), and the photoluminescence properties have been investigated from both experimental and theoretical aspects. It is found that the lowest-energy electronic transitions in the ultraviolet–visible (UV–Vis) absorption spectra of Au3–P (403 nm) and Au3–F (425 nm) exhibit a slight bathochromic shift compared to the corresponding transitions in the spectra of 1-pyrenamine and 3-aminofluoranthene, respectively. In addition, the dichloromethane solutions of Au3–P and Au3–F complexes clearly display blue and yellowish-green fluorescence, respectively. These results will help to design and prepare organic–inorganic nanocluster hybrid luminescent materials for potential applications in (bio)sensors, bioimaging and optoelectronic devices.