A novel concept for the synthesis of multiply doped gold clusters [(M@Au_nM?_m)L_k]^q+

Heterometal-doped gold clusters are poorly accessible through wet-chemical approaches and main-group-metal- or early-transition-metal-doped gold clusters are rare. Compounds [M(AuPMe₃)₁₁(AuCl)]³⁺ (M=Pt, Pd, Ni) (1-3), [Ni(AuPPh₃)_(8-2n)(AuCl) ₃(AlCp)_n] (n=1, 2) (4, 5), and [Mo(AuPMe₃) ₈ (GaCl₂)₃(GaCl)]⁺ (6) were selectively obtained by the transmetalation of [M(M?Cp)_n] (M=Mo, E=Ga, n=6; M=Pt, Pd, Ni, M?=Ga, Al, n=4) with [ClAuPR₃] (R=Me, Ph) and characterized by single-crystal X-ray diffraction and ESI mass spectrometry. DFT calculations were used to analyze the bonding situation. The transmetalation proved to be a powerful tool for the synthesis of heterometal-doped gold clusters with a design rule based on the 18 valence electron count for the central metal atom M and in agreement with the unified superatom concept based on the jellium model. Golden cages: When complexes [M(M?R)_a] (M=Mo, Ni, Pd, Pt; M?=Al, Ga; R=CH₃, C ₅Me₅; a≥4) react with ClAuPR₃ (R=Ph, Me), the interstitial metal atom M (blue) is transferred from the M?_a cage (gray) to a Au_n shell (yellow). Multiply metal-doped gold clusters [(M@Au_nM?_m)L_k]^q+ (n+m≥9; q=0, 1, 3) result. The design rule of the new clusters is based on the 18 valence electron count for the central metal atom M and agrees with the unified superatom concept based on the jellium model.