Germanium Tetramers

Fig- 2-5-6. X -ray crystal structure of Ge4R 4, R = SiBuh [35], H atoms are not shown. 

The testing of germanium halide derivatives of other bulky substituents such as Bu did not afford (GeBu% species. Instead, a variety of polygermane species with interesting structures were isolated [38]. The use of the more bulky -CMeEt2 

---

Ugrinov A, Sevov SC (2003) [Geg=Geg=Geg=Geg] a linear tetramer of nine-atom germanium clusters, a nanorod. Inorg Chem 42 5789... 

With less bulky groups on the nitrogen atoms, the most common oligomer formed by the hypothetical monomeric group 14 imides, M=NR (M = Ge, Sn, Pb), is the cubic tetramer, e.g. [M()i3-N Bu)]4. This is especially true for the heavier (larger) elements tin and lead for which, in contrast to germanium, cubanes are observed even when R = 2,6- Pr2C6H3. " ... 

The most abundant species in the equilibrium vapor over condensed metals are generally atoms as shown by Knudsen effusion mass spectrometry. The relative abundance of the homonuclear diatomic molecules was determined to be between 10 and 10 percent if they are detectable. Exceptions are bismuth and antimony. The dimer partial pressure over liquid bismuth at temperatures below 1000 K exceeds that of the monomer [83, 164, 165]. The tetramer is the most abundant species over liquid antimony [85]. Other polyatomic homonuclear species have so far been observed under equilibrium conditions for some of the alkali metals, as well as the group Ib, IVb, and Vb metals. Particularly large polymers up to 667 and Sn7 were detected for germanium [84,166,167] and tin [168],... 

Germanium analogs of cyclosUoxanes reported to date include (R2GeO) trimers and tetramers (e.g. with R = Me, Et, Pr, Ph, etc.) but they did not attract as much interest as their silicon relatives. ... 

---