Mixed platinum-rhodium carbonyl clusters. The isolation of [Pt4Rh18(CO)35]4-, an example of a cherry-like cluster with a semiexposed tetraplatinum core

Syntheses, Structures, and Electrochemistry of the Defectiveccp[Pt33(CO)38]2–and thebcc[Pt40(CO)40]6–Molecular Nanoclusters

“…Herein, we report the syntheses and total structures of the molecular [Pt 33 (CO) 38 ] 2− and [Pt 40 (CO) 40 ] 6− nanoclusters. The latter represents the first case of a high-nuclearity Pt carbonyl cluster adopting a bcc structure, whereas [Pt 33 (CO) 38 ] 2− displays a defective ccp structure.…”

“…These redox processes are better defined in cyclic voltammetry for the more regular [Pt 40 (CO) 40 ] 6− nanocluster than the defective and distorted [Pt 33 (CO) 38 ] 2− . Electrochemical in situ Fourier transform infrared (FTIR) spectroscopy allowed the characterization of nine and eight differently charged species of [Pt 33 (CO) 38 ] n (n = 0 to −4, −6 to −9) and [Pt 40 (CO) 40 ] n (n = −4 to −11), respectively. 20,25,26 The molecular structure of the [Pt 33 (CO) 38 ] 2− nanocluster ( Figure 1) is composed of a defective Pt 33 ccp metal core decorated by 38 CO ligands.…”

“…Electrochemical in situ Fourier transform infrared (FTIR) spectroscopy allowed the characterization of nine and eight differently charged species of [Pt 33 (CO) 38 ] n (n = 0 to −4, −6 to −9) and [Pt 40 (CO) 40 ] n (n = −4 to −11), respectively. 20,25,26 The molecular structure of the [Pt 33 (CO) 38 ] 2− nanocluster ( Figure 1) is composed of a defective Pt 33 ccp metal core decorated by 38 CO ligands. The metal kernel of this cluster may be derived from the one of the previously reported [Pt 38 (CO) 44 ] 2− (Figure 2).…”

“…The metal kernel of this cluster may be derived from the one of the previously reported [Pt 38 (CO) 44 ] 2− (Figure 2). 20,25,26 The latter is a truncated octahedron of frequency three composed of five layers along the (100) direction of the idealized ccp lattice, comprising 4, 9, 12, 9, and 4 Pt atoms, respectively (Figure 2c) 38 ] 2− is formally obtained after removing one of the two external Pt 4 layers and a further Pt-atom from the adjacent Pt 9 layer. Overall, the Pt 33 framework is composed along (100) of four layers, comprising 4, 9, 12, and 8 atoms, respectively ( Figure 2a).…”

“…As a result of removing these five Pt atoms, one vertex of the Pt 6 octahedron, which was fully interstitial in [Pt 38 (CO) 44 ] 2− , is now exposed on the surface of the cluster leaving only a square pyramidal Pt 5 fragment as fully interstitial. In view of its defective ccp structure, the Pt 33 core of [Pt 33 (CO) 38 ] 2− displays significant distortions and deformations compared to an idealized Pt 33 ccp structure ( Figure 2b) 38 ] 2− may be obtained by drawing an idealized Pt 33 ccp core with all the Pt−Pt contacts set equal to 2.82 Å, which is the average value found in the real cluster ( Figure 2b). First of all, this idealized Pt 33 ccp fragment displays 119 Pt−Pt contacts, and not 121 as in [Pt 33 (CO) 38 ] 2− ( Figure 3).…”