Ligand Control of Manganese Telluride Molecular Cluster Core Nuclearity

Abstract

We report the synthesis, structural diversity, and chemical behavior of a family of manganese telluride molecular clusters whose charge-neutral cores are passivated by two-electron donor ligands. We describe three different core structures: a cubane-type Mn4Te4, a prismane Mn6Te6, and a dicubane Mn8Te8. We use various trialkylphosphines and N-heterocyclic carbenes (NHCs) as surface ligands and demonstrate that the formation of the different cluster core structures is controlled by the choice of ligand: bulky ligands such as P(i)Pr3, PCy3, or (i)Pr2NHC ((i)Pr2NHC = 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene) form the cubane-type core, while the smaller PMe3 produces the prismane core. The intermediate-sized PEt3 produces both cubane and prismane species. These manganese telluride molecular clusters are labile, and the capping phosphines can be replaced by stronger ligands, while the internal core structure of the cluster remains intact. The interplay of structural diversity and ligand versatility and lability makes these clusters potentially useful building blocks for the assembly of larger aggregates and extended structures. We demonstrate the simplest prototype of these solid-forming reactions: the direct coupling of two Mn4Te4((i)Pr2NHC)4 units to form the dicubane Mn8Te8((i)Pr2NHC)6. We also postulate the prismatic Mn6Te6 as the common ancestor of both Chevrel-type M6E8 and octanuclear rhombododecahedral M8E6 molecular clusters (M = transition metal and E = chalcogen), and we discuss the core structure of our molecular clusters as recognizable building units for the zinc blende and the hypothetical wurtzite lattices of MnTe.

Synthesis and coordination chemistry of cyclic seleno- and telluroureas

“…The lower chemical stability of the C = Te bond may be exploitable in the design of new non-innocent ligands, which may transfer tellurium to chalcophilic metals. For instance, the reaction of 1,3-diisopropylimidazole tellone with a Mn 0 precursor was recently shown to yield insertion products in which (MnTe) n clusters formed cubane and dicubane motifs, ligated by the remaining NHC fragment [69]. This type of chemistry has the potential to generate other new metal chalcogenide clusters.…”

Intermetalloid Clusters: Molecules and Solids in a Dialogue

“…The arrangement of the Ge core represents an analogy to the Ge II high pressure modification.Geatoms blue, Fe atoms red, C atoms gray,Oatoms dark gray.G ecluster is represented as yellow polyhedron, Cp ligands are drawn schematically. [97] ForH ume-Rothery phase-inspired metal combinations, that is,transition metals (M)and group 12 or 13 elements (E), as ystematic access towards ligand-stabilized coordination and cluster compounds [M a E b ](R) n is provided via low-valent organoelement species E I R( R = hydrocarbon ligand, for example,C p*, Me) as exotic ligands at transition-metal centers.T he multifunctional nature of these one-and twoelectron donors as reducing agents,v ersatile ligands,a nd sources for zero-valent E metals for cluster core formation results in an extraordinarily rich coordination chemistry, ac omprehensive overview of which is given in the recommended literature. As shown in the previous section, comparable strategies were successfully applied in the bottom-up synthesis of Zintl clusters and for the preparation of bi-and trimetallic clusters of the dissimilar d-block and group 14-15 metals.Inaquite similar approach, Dehnen et al reported the formation of the PdTeChevrel-type cluster [Pd 6 (m 3 -Te) 8 ] 4À in the reaction of ab inary PbTep hase with [Pd(PPh 3 ) 2 Cl 2 ] (Figure 13).…”

“…[96] In more recent studies on the impact of the stabilizing ligand Lonthe geometry and nuclearity of manganese telluride clusters [Mn a Te b ]L n (a = b = 4, 6, 8), the resulting core geometries were further discussed as recognizable building units in zinc blende and hypothetical wurtzite-type lattices of MnTe phases. [97] ForH ume-Rothery phase-inspired metal combinations, that is,transition metals (M)and group 12 or 13 elements (E), as ystematic access towards ligand-stabilized coordination and cluster compounds [M a E b ](R) n is provided via low-valent organoelement species E I R( R = hydrocarbon ligand, for example,C p*, Me) as exotic ligands at transition-metal centers.T he multifunctional nature of these one-and twoelectron donors as reducing agents,v ersatile ligands,a nd sources for zero-valent E metals for cluster core formation results in an extraordinarily rich coordination chemistry, ac omprehensive overview of which is given in the recommended literature. [98] 4.1.…”

“…and are readily obtained as intermediates on the way to solid‐state intermetallics by treatment of labile first‐row transition‐metal carbonyl or olefin complexes with trialkylphosphine tellurides . In more recent studies on the impact of the stabilizing ligand L on the geometry and nuclearity of manganese telluride clusters [Mn a Te b ]L n ( a = b =4, 6, 8), the resulting core geometries were further discussed as recognizable building units in zinc blende and hypothetical wurtzite‐type lattices of MnTe phases …”

Intermetalloide Cluster: Moleküle und Festkörper im Dialog

“…[85] Ausgehend von K 5 Sb 4 wurde zudem ein bemerkenswertes Gegenstück zum oben erwähnten Au 3 -verbrückten Ge 9 -Zintl-Cluster erhalten:d as aromatische [Sb 3 Au 3 Sb 3 ] 3À -Anion, das aus drei gestapelten Dreiecken besteht. [97] FürH ume-Rothery-Phasen-inspirierte Metallkombinationen, zum Beispiel der Übergangsmetalle (M)und Gruppe-12-oder Gruppe . Niedervalente und andere molekulare Precursor Alternative Wege zu kompositionell und teilweise strukturell verwandten heterometallischen Clustern aus der Kombination von d-Block-Metallen und Gruppe-14-und Gruppe-15-Elementen beinhalten deren Aufbau ausgehend von kleinen organometallischen Bausteinen.…”