Aluminium and Gallium Clusters: Metalloid Clusters and their Relationship to the Bulk Phases, to Naked Clusters and to Nanoscaled Materials

Cationic cluster formation versus disproportionation of low-valent indium and gallium complexes of 2,2’-bipyridine

“…Cotton defined the term metal atom cluster compound as ‘those containing a finite group of metal atoms which are held together entirely, mainly, or at least to a significant extent, by bonds directly between the metal atoms even though some non-metal atoms may be associated intimately with the cluster' 1 . Meanwhile, the term cluster has been expanded, describing various ensembles of bonded atoms (both metal and non-metal) or molecules, thus including compounds such as the boranes and carboranes 2 3 , Zintl-like phases 4 , salt-like clusters 5 as well as metalloid clusters 6 . Among the many routes leading to metal atom cluster compounds, the reductive and anionic syntheses prevail: such clusters are typically electron deficient and have a strong demand for additional electrons that can be provided by reductants such as alkaline metals or through electron transfer reactions like disproportionations 6 7 .…”

“…Meanwhile, the term cluster has been expanded, describing various ensembles of bonded atoms (both metal and non-metal) or molecules, thus including compounds such as the boranes and carboranes 2 3 , Zintl-like phases 4 , salt-like clusters 5 as well as metalloid clusters 6 . Among the many routes leading to metal atom cluster compounds, the reductive and anionic syntheses prevail: such clusters are typically electron deficient and have a strong demand for additional electrons that can be provided by reductants such as alkaline metals or through electron transfer reactions like disproportionations 6 7 . Alternatively, aggregation can be achieved by applying strong donor ligands: for example, the carbene-mediated formation of the neutral P 12 non-metal cluster 8 .…”

Chromium, Iron and Cobalt Carbonyl Complexes with Gallium Halides: Synthesis and Structures

“…[(CO) 4 [34] [(CO) 4 [8] [Cp(CO) 2 [36] [Cp(CO) 2 FeGaCl 2 (thf)] 231.7(1) 1990 (s), 1995 (s) [37] [Cp(CO) 2 FeGa(R N )(BH 4 )] 237.5 1975 (vs), 1920 (vs) [38] [Fe 2 (CO) 6 {μ-GaSi(SiMe 3 ) 3 } 3 ] 238.18 1964 (s), 1921 (s) [9] [Fe 2 (CO) 6 [40] [{Cp(CO) 2 [30,31] [{Cp(CO) 2 [30,31] [{Cp(CO) 2 [42] [(CO) 4 FeGa(η 1 -C 2 H 3 )(thf)] 2 251.0 - [43] [(CO) 5 CrGaCp*] 240.46 (7) 2052 (s), 982 (s), 1918 (vs), 902 (vs) [8] [(CO) 5 CrGaC 4 H 2 (tBu) 2 P] 239.0(1) 2022 (m), 1936 (sh), 1870 (s) [44] [(CO) 5 CrGaCl(tmeda)] 245.6(1) 2033 (s), 1947 (s), 1900 (vs) [45] [(CO) 5 CrGaCH 3 (tmeda)] 247.9(1) 2013 (vs), 1920 (s), 1844 (vs) [46] [(CO) 5 [45] [(CO) 6 Co 2 (GaCp*) 2 ] 238. 8 2023, 1989, 1953, 1948 [8] [(CO) 6 [12] subhalides with the corresponding metallated silanides.…”

Many Mg–Mg bonds form the core of the Mg16Cp*8Br4K cluster anion: the key to a reassessment of the Grignard reagent (GR) formation process?

“…However, since MgX radicals in metastable solutions rapidly disproportionate above –40 °C to form a mirror of Mg metal and their dihalides, the generation of metalloid magnesium clusters from these highly reactive species seemed for a long while not to be possible. Nevertheless, given our extensive experience with the generation of about 50 metalloid Al/Ga clusters during the last 25 years, 17 metalloid magnesium clusters remained a sought-after goal. For years, we dreamed of introducing a novel dimension to the chemistry of magnesium in analogy to the new area of aluminum and gallium organometallic chemistry.…”