Observable but Not Isolable: The RhAu₂₄(PET)₁₈¹⁺ Nanocluster

Abstract

The synthesis and characterization of RhAu24(PET)18 (PET = 2‐phenylethanethiol) is described. The cluster is cosynthesized with Au25(PET)18 and rhodium thiolates in a coreduction of RhCl3, HAuCl4, and PET. Rapid decomposition of RhAu24(PET)18 occurs when purified from the other reaction products, precluding the study of isolated cluster. Mixtures containing RhAu24(PET)18, Au25(PET)18, and rhodium thiolates are therefore characterized. Mass spectrometry, X‐ray photoelectron spectroscopy, and chromatography methods suggest a combination of charge–charge and metallophilic interactions among Au25(PET)181−, rhodium thiolates and RhAu24(PET)18 resulting in stabilization of RhAu24(PET)18. The charge of RhAu24(PET)18 is assigned as 1+ on the basis of its stoichiometric 1:1 presence with anionic Au25(PET)18, and its stability is contextualized within the superatom electron counting rules. This analysis concludes that the Rh atom absorbs one superatomic electron to close its d‐shell, giving RhAu24(PET)181+ a superatomic electron configuration of 1S21P4. Overall, an updated framework for rationalizing open d‐shell heterometal dopant electronics in thiolated gold nanoclusters emerges.

Superatom‐in‐Superatom [RhH@Ag24(SPhMe2)18]2− Nanocluster

“…Unlike the transition metals with closed d‐shells, doping of metals with partially filled d‐shells has not been studied in detail. Only a few researchers reported the existence of Rh‐doped and Ir‐doped clusters, in which the formal charge of the dopant was −1 [8c, 10] . The RhH co‐doped NC prepared in this study is unique, suggesting that the incorporated hydride plays an important role in the formation of the stable cluster superatom.…”

“…Chemie Forschungsartikel atomic orbital. Thef ully occupied 4d z 2 orbital has significant contributions from the H1s(56 %) and Rh 4d orbitals (37 %) with an egligible contribution from the Rh 5s orbital, while the other dorbitals show the sole contribution from the Rh 4d orbitals,l eading to aP d-like 4d 10 configuration ([Kr]4d 10 ). This result strongly suggests that RhH is as uperatomic construct of the Pd atom with the same electronic configuration.…”

“…[9] Recently,Ackerson et al identified the chemical composition of aR h-doped cluster [RhAu 24 (SR) 18 ] 1+ by mass spectrometry,although it could not be isolated as ap ure cluster product. [10] ). These results unambiguously demonstrated that ac luster superatom could be doped with as uperatom, providing the first example of superatom-in-superatom NCs.…”

“…[9] Recently,Ackerson et al identified the chemical composition of aR h-doped cluster [RhAu 24 (SR) 18 ] 1+ by mass spectrometry,although it could not be isolated as ap ure cluster product. [10] Synthesis of as table thiolate-protected metal NC doped with open d-shell metals remains ahighly challenging task.…”

Superatom‐in‐Superatom [RhH@Ag24(SPhMe2)18]2− Nanocluster

“…Research Articles atomic orbital. Thef ully occupied 4d z 2 orbital has significant contributions from the H1s(56 %) and Rh 4d orbitals (37 %) with an egligible contribution from the Rh 5s orbital, while the other dorbitals show the sole contribution from the Rh 4d orbitals,l eading to aP d-like 4d 10 configuration ([Kr]4d 10 ). This result strongly suggests that RhH is as uperatomic construct of the Pd atom with the same electronic configuration.…”