Germanium formed with

Germanium forms divalent compounds with all the halogens. Germaniunil 1) chloride can be prepared by passing the vapour of germanium(IV) chloride (see below) over heated germanium. The reaction is reversible and disproportionation of germanium(II) chloride is complete at about 720 K at atmospheric pressure ... 

Some physical properties of the elements are compared in Table 10,2. Germanium forms brittle, grey-white lustrous crystals with the diamond structure it is a metalloid with a similar electrical resistivity to Si at room temperature but with a substantially smaller band gap. Its mp, bp and associated enthalpy changes are also lower than for Si and this trend continues for Sn and Pb which are both very soft, low-melting metals. 

All studied model compounds can distinctly be divided into three groups (Table VII). The first group is composed of substances in which the sulfur, selenium or cyclopentadienyl anion acts as an anionic center. They exist only in open betaine forms, and their PES do not contain local minima corresponding to cyclic isomers. The second group contains compounds with arsonium cationic and oxide anionic centers and silicon and germanium betaines with arsonium and amide centers. They exist as cyclic isomers and their PES have no local minima corresponding to the open forms. Finally, the third group consists of six studied compounds with phosphonium cationic and oxide or amide anionic centers and arsonium-imide betaine. Their PES have minima for both cyclic and open forms separated by low barriers. 

When Germanium dioxide is 99.999% pure, it is used as a semiconductor in transistors, in diodes, and to make special infrared transmitting glass. (The same types of compounds can be formed with chlorine, and Germanium IV) compounds occur mostly with the sulfide of zinc ore.)... 

Germanium forms six coordinate adducts, such as GeCl4(L)2 with many neutral ligands. 

Nanostructured germanium structures with mesoporous channels running through them can represent a different form of framework materials with exciting physical properties. When bulk germanium is penetrated by a regular array of mesopore channels, nanosized walls can be created that can exhibit electronic and optical characteristics similar to those of discrete nanodots [33]. 

Consider an interface formed by joining together an n-type semiconductor (e.g., germanium doped with arsenic atoms, which donate electrons to the conduction... 

A germanium complex with ethylenediaminetetraacetic acid (Hedta) 532 has a pen-tadentate edta ligand with one protonated acetate group which does not coordinate, forming a six-coordinate complex1150. 

Germanium forms a wide range of compounds with hydrogen, silicon, the heavier group 14 elements, some main group metals, and transition metals. Catenated hydrides, Ge H2 +2, have already been discussed. The majority have carbon bonded to Ge and are included in the next article (see Germanium Organometallic Chemistry). 

Use the group structure of the periodic table to predict the empirical formulas for the binary compounds that hydrogen forms with the elements germanium, fluorine, tellurium, and bismuth. 

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