The Clusters [M_a(ECp*)_b] (M=Pd, Pt; E=Al, Ga, In): Structures, Fluxionality, and Ligand Exchange Reactions

Abstract

The synthesis and structural characterization of the novel homoleptic cluster complexes [Pd2(GaCp*)2(mu2-GaCp*)3] (1c), [Pd3(GaCp*)4(mu2-GaCp*)4] (2b) and [Pd3(AlCp*)2(mu2-AlCp*)2(mu3-AlCp*)2] (3) (Cp*=C5Me5) are presented. Furthermore, ligand exchange reactions of these cluster complexes are explored. In contrast to the electronically and sterically saturated complexes [M(ECp*)4] (M=Ni, Pd, Pt), the new unsaturated analogues [M(a)(ER)b] (E=Al, Ga, In) react with a variety of typical ligands (Cp*Al, CO, phosphines, isonitriles) to give new di- and tri-substituted compounds like [Pt2(GaCp*)2(mu2-AlCp*)3] (1d), [PdPt(GaCp*)(PPh3)(mu2-GaCp*)3] (4b), or [Pd3(PPh3)3(mu2-InCp*)(mu3-InCp*)2] (8). The trends of the reactivity of [M(a)(ER)b] as well as their fluxional behavior in solution has been elucidated by NMR spectroscopy, resulting in a mechanistic rationale for the ligand exchange reactions as well as the fluxional processes.

Synthesis of the Sterically Related Nickel Gallanediyl Complexes [Ni(CO)3(GaAr′)] (Ar′ = C6H3-2,6-(C6H3-2,6-iPr2)2) and [Ni(CO)3(GaL)] (L = HC[C(CH3)N(C6H3-2,6-iPr2)]2): Thermal Decomposition of [Ni(CO)3(GaAr′)] to give the Cluster [Ni4(CO)7(GaAr′)3]

“…Later, the range of available examples was further expanded with use of terphenyl [4][5][6] and b-diketiminate and related ligands [7][8][9][10][11]. The ability of these low-valent metal (I) compounds to act as strong terminal or bridging r-donor ligands has been well demonstrated by the experimental studies of Fischer, Jutzi and Uhl and by the theoretical work of Frenking [12][13][14][15][16][17][18][19][20]. Such species are of interest not only from a fundamental structure/bonding perspective [20,21], but also from the viewpoint of potential applications of this class of compounds (e.g.…”

The Intermetalloid Cluster [(Cp*AlCu)6H4], Embedding a Cu6 Core Inside an Octahedral Al6 Shell: Molecular Models of Hume–Rothery Nanophases

“…The Al-Cu intermetalloid cluster [(Cp*AlCu) 6 Nanoalloys and intermetallic clusters A a B b with control of size (a + b) or composition (a/b) are an important avenue in materials science and hold promise for advanced applications (for example, selective catalysis), as the raised complexity of the mixed-metal systems allows going beyond the performance of homometallic parent species.[1] The development of synthetic methods for deriving mixed transition metal (A) main-group metal (B) clusters bottom-up by soft, wet chemistry is a particularly demanding challenge in this respect. For example, based on Zintl ion chemistry, fascinating binary and ternary intermetalloid molecular clusters with components B from Groups 14 and 15 have been demonstrated.…”

“…[5] Representative examples include the compounds [Pd 3 (AlCp*) 6 ], [6] [Mo(ZnMe) 9 (ZnCp*) 3 ], [7] and [Pd 2 Zn 6 Ga 2 (Cp*) 5 (Me) 3 ].…”

Molekulare Ausschnitte von Mo/Zn‐Hume‐Rothery‐Phasen: Synthese und Struktur von [{Mo(CO)4}4(Zn)6(μ‐ZnCp*)4]

“…Unser Fokus lag dabei auf homoleptischen galliumreichen Komplexen und Clustern des Typs [T a (GaR) b ] (T= Übergangs-metall, R = Cp*, L; b > a). [17][18][19] risierung dieser endohedralen Käfigverbindungen sowie die Aufklärung ihrer außergewöhnlichen Bindungsverhältnisse berichtet. [22] Die Molekülstruktur von 1 im Festkörper ist in Abbildung 1 gezeigt.…”