The Influence of Flexibility of Alkynyl Ligands on the Formation of an Fcc Au110 Nanocluster

Abstract Isomerization of nanoclusters is helpful for understanding the relationships between structures and properties. Surface‐protecting ligands play a crucial role in controlling the atomic packing mode of the inner core. The synthesis and total structural determination of the all alkynyl‐protected gold nanocluster (NEt 3 CH 2 Cl) 2 [Au 110 (C≡CC 3 H 6 Ph) 48 ] ( Au 110 ‐1 ) are reported. Au 110 ‐1 and the previously reported [Au 110 (C≡CC 6 H 4 ‐4‐CF 3 )] 2− ( Au 110 ‐2 ) constitute the largest alkynyl‐protected nanocluster quasi‐isomers (> 100 metal atoms). Both Au 110 consist of an fcc Au 86 kernel and a shell of 24 RC≡C─Au─C≡CR staples, but the specific arrangements are different. The application of the flexible alkynyl ligands creates a significant difference in the face‐centered cubic (fcc) kernel structure in Au 110 ‐1 , showing a different electronic structure, thermal‐ and photo‐stability. Transient absorption spectra reveal that Au 110 ‐1 still does not show any metallic characteristics, even though it has a smaller energy gap ( E g) than Au 110 ‐2 .