Synthesis and Reactivity of Multinuclear Gold Complexes with (Diphenylphosphanyl)ferrocene and Oxygen Ligands

• Published in: Angewandte Chemie International Edition Vol. 60; no. 13; pp. 6992 - 6996
• Main Authors: Schulz, Jiří, Císařová, Ivana, Gyepes, Róbert, Štěpnička, Petr
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 22-03-2021
• Edition: International ed. in English
• Subjects: aurophilicity; Chemical synthesis; cluster compounds; Clusters; Coordination compounds; Crystallization; Gold; Hydroxides; Ligands; metallocenes; Oxygen; phosphane ligands; Redox reactions; gold; aurophilicity; cluster compounds; phosphane ligands; metallocenes
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202014359

AuI complexes combining hard oxygen and soft (diphenylphosphanyl)ferrocene (L) ligands in their molecules were synthesized, viz. the gold hydroxides [Au(OH)(L‐κP)] (5) and [{Au(L‐κP)}2(μ‐OH)][BF4] (4), and the oxonium cluster [{Au(L‐κP)}3(μ3‐O)][BF4] (1). In‐situ auration of 1 produced [{Au(L‐κP)}4(μ4‐O)][BF4]2 (2), which spontaneously converted into a dimeric tetragold complex featuring bridging phosphanylferrocenyl groups geminally diaurated in position 2 of the ferrocene scaffold. The same complex and its isomer incorporating ferrocene‐1,1′‐diyl bridges resulted similarly from 4. Upon crystallization, compound 5 underwent a redox reaction, producing a structurally unique, crown‐like, mixed‐valent Au0/AuI cluster, [Au7(L‐κP)6]OH. Compounds 1 and 5 were used to prepare the analogous, N‐bridged complexes, [{Au(L‐κP)}3(μ3‐NFc)][BF4] (Fc=ferrocenyl) and [{Au(L‐κP)}4(μ4‐N)][BF4]. The compounds were structurally characterized and further studied by DFT calculations.
Compounds [(μ‐OH){AuL}2][BF4] and [(μ4‐O){AuL}4][BF4] (L=(diphenylphosphanyl)ferrocene) undergo facile auration at their ferrocene units to produce isomeric tetragold(I) complexes. Conversely, the gold hydroxide [Au(OH)L] rearranges to a unique heptanuclear Au0/AuI cluster [Au7L6]OH. [Au(OH)L] also opens access to Au‐aryl complexes and polynuclear Au complexes with N‐bridging ligands.