[NiS(PEt)]: an open-shell nickel sulfide nanocluster with a "metal-like" core

• Published in: Chemical science (Cambridge) 2022-05, Vol.13 (18), p.5171-5175
• Main Authors: Touchton, Alexander J, Wu, Guang, Hayton, Trevor W
• Format: Article
• Language: English
• Subjects: Chemistry; Crystallography; Electron states; Magnetic measurement; Metal bonding; Molecular orbitals; Nanoclusters; Nickel sulfide; NMR spectroscopy; Noble metals; Superconducting quantum interference devices; Toluene
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/d2sc00960a

Reaction of [Ni(1,5-cod) 2 ] (30 equiv.) with PEt 3 (46 equiv.) and S 8 (1.9 equiv.) in toluene, followed by heating at 115 °C for 16 h, results in the formation of the atomically precise nanocluster (APNC), [Ni 30 S 16 (PEt 3 ) 11 ] ( 1 ), in 14% isolated yield. Complex 1 represents the largest open-shell Ni APNC yet isolated. In the solid state, 1 features a compact "metal-like" core indicative of a high degree of Ni-Ni bonding. Additionally, SQUID magnetometry suggests that 1 possesses a manifold of closely-spaced electronic states near the HOMO-LUMO gap. In situ monitoring by ESI-MS and 31 P{ 1 H} NMR spectroscopy reveal that 1 forms via the intermediacy of smaller APNCs, including [Ni 8 S 5 (PEt 3 ) 7 ] and [Ni 26 S 14 (PEt 3 ) 10 ] ( 2 ). The latter APNC was also characterized by X-ray crystallography and features a nearly identical core structure to that found in 1 . This work demonstrates that large APNCs with a high degree of metal-metal bonding are isolable for nickel, and not just the noble metals. The atomically-precise nanocluster, [Ni 30 S 16 (PEt 3 ) 11 ], features a compact "metal-like" core indicative of a high degree of Ni-Ni bonding, along with an open-shell ground state.