Cyclopentadiene Based Low-Valent Group 13 Metal Compounds: Ligands in Coordination Chemistry and Link between Metal Rich Molecules and Intermetallic Materials

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

“…Over the years, we obtained a library of metal-rich molecules of the general formula [A a (BR) b ]. [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 ]. [8] The intermetallic cores M n = A a B b (b > a; n = a + b) are stabilized by wrapping the core structure M n into an all-hydrocarbon shell R c (c < n).…”

“…The Cu 6 core adopts a bicapped tetrahedral cluster structure and this unit is incarnated into an octahedral Al 6 shell. Interestingly, the arrangement of atoms in the M 12 units can be correlated to the nested polyhedra of well-known intermetallic phases, such as Cu 9 Al 4 , MgCu 2 (the cubic Laves phase), Be 5 Au, a-Mn (the c-phase), which are all structurally closely related to Cu 5 Zn 8 (g-brass). The 26-atom nested polyhedral clusters of g-brass (Figure 1) consist of successive layers of an inner tetrahedron (IT, orange), an outer tetrahedron (OT, green), an octahedron (OH, pale blue), and a distorted cuboctahedron (CO, gray).…”

“…These studies are based on a profound knowledge on the coordination chemistry of low-valent Group 12/ 13 metal (B) species at transition-metal centers. [5] In particular, the Al-Fe compound [Fe(AlCp*) 5 ] is already known. [28] Thus, more examples of the general type [A a B b ]R c , and even larger clusters (a + b @ c), may be discovered in the future.…”

Weak Arene Stabilization of Bulky Amido‐Germanium(II) and Tin(II) Monocations

“…Similar ambiphilic behavior is now well established for the neutral, isoelectronic Group 13 analogues of the cations, that is, the one-coordinate metal diyls, RMD (M = Al, Ga, In, or Tl). [3] Although truly one-coordinate cations of the type RED + are unknown, a variety of kinetic and/or electronic stabilization strategies have been employed to allow an entry to higher-coordinate examples. These include the use of anionic [4] or neutral [5] arene donors (as in 1 and 2), and bi- [6][7][8] or polydentate [9] N-donor ligands (as in 3 and 4).…”

Intermetalloid Clusters: Molecules and Solids in a Dialogue

“…[91] lizing matrix. [98] 4.1. [95] Related phosphine-stabilized transition-metal telluride clusters,l ike the isostructural [M 6 Te 8 ](PR 3 ) 6 (M = Cr,F e, Co), the anti-Chevrel-type [Ni 9 Te 6 (PEt 3 ) 8 ]o rt he metalloid [Ni 20 Te 18 (PEt 3 ) 12 ]w ere already reported in the 1990s by Steigerwald et al 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.…”