Chiroptical Activity Enhancement via Structural Control: The Chiral Synthesis and Reversible Interconversion of Two Intrinsically Chiral Gold Nanoclusters

• Published in: Journal of the American Chemical Society Vol. 141; no. 6; pp. 2384 - 2390
• Main Authors: Wang, Jia-Qi, Guan, Zong-Jie, Liu, Wen-Di, Yang, Yang, Wang, Quan-Ming
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 13.02.2019
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/jacs.8b11096

We report the synthesis and crystal structure determination of two novel chiral gold nanoclusters. By utilizing BINAP, we isolate atomically precise intrinsically chiral Au nanoclusters [Au9(R-/S-BINAP)4]­(CF3COO)3 and [Au10(R-/S-BINAP)4(p-CF3C6H4CC)]­(CF3COO)3 in high yield with one-pot synthesis. Au 9 has C 2 geometry, while Au 10 is C 1 symmetric. Interestingly, reversible interconversion between Au 9 and Au 10 can be realized by the addition or removal of a RCCAu component. The transformation from Au 9 to Au 10 leads to significant enhancement of CD signals. The maximum anisotropy factor in the visible region of [Au10(BINAP)4(p-CF3C6H4CC)]3+ is the hitherto largest (up to 6.6 × 10–3) among gold nanoclusters, which is approximately twice of that of [Au9(BINAP)4]3+. This work demonstrates that the chiroptical activity of gold nanoclusters can be modulated by structural control through the introduction of second ligands.