Germanium characterization

Characterization of Germanium PhosphosUicate Films Prepared by MCVD," presentation, at the faU meeting of the American Ceramic Society, 1981, Bedford, Pa, 1981. 

Physical Properties. Raman spectroscopy is an excellent tool for investigating stress and strain in many different materials (see Materlals reliability). Lattice strain distribution measurements in siUcon are a classic case. More recent examples of this include the characterization of thin films (56), and measurements of stress and relaxation in silicon—germanium layers (57). 

Already partially resolved methyl-1-naphthylphenylgermanium hydride ([otp°° + 10) could also be separated on column A into two fractions characterized by [a] g5 = + 80 and —42 respectively. Partial resolution could even be obtained for the configuration-ally less stable methyl-1 -naphthylphenylgermanium chloride if the elution was carried out with diethyl ether 53), which is much less nucleophilic towards germanium than methanol, which causes the racemization of this compound. 

II. Ultra-Pure Germanium Crystal Growth and Characterization... 

Another example for a five-coordinated germanium complex (10-Ge-5 anionic complex) has already been described above (see Section IV.B.2.a.ii Figure 23). An unusual rectangular pyramidal germanium(IV) anion was synthesized according to the reaction shown in Figure 30. The anion was characterized by 31P and 1H NMR studies125. 

Reactions of Germanium Dihalides. Due to its ease of preparation, Gel2 pro-sesses the best characterized reaction chemistry of the dihalides of germanium. 

The electrosynthesis of metalloporphyrins which contain a metal-carbon a-bond is reviewed in this paper. The electron transfer mechanisms of a-bonded rhodium, cobalt, germanium, and silicon porphyrin complexes were also determined on the basis of voltammetric measurements and controlled-potential electrooxidation/reduction. The four described electrochemical systems demonstrate the versatility and selectivity of electrochemical methods for the synthesis and characterization of metal-carbon o-bonded metalloporphyrins. The reactions between rhodium and cobalt metalloporphyrins and the commonly used CH2CI2 is also discussed. 

In summary, the four chemical systems described in this paper demonstrate the versatility and selectivity of electrochemical methods for synthesis and characterization of metal-carbon a-bonded metalloporphyrins. The described rhodium and cobalt systems demonstrate significant differences with respect to their formation, stability and to some extend, reactivity of the low valent species. On the other hand, properties of the electroche-mically generated mono-alkyl or mono-aryl germanium and silicon systems are similar to each other. 

Germanium(iv) and tin(rv) compounds M(BH4)4 (M = Ge 51, Sn 52) have been synthesized by simple salt metathesis and characterized by IR spectroscopy.49 The cyclic Lewis acid/base adducts between (o-C6F4FIg)3 and [BH4]-, for example, [( -C6F4Hg)3(BFI4)2]2- 53 and [ ( -C6F4Hg)3 2(BH4)]- 54, have been characterized by IR and NMR spectroscopies.50... 

A number of four-membered cyclic germanium compounds have been prepared and characterized.14-16 Mild thermolysis of the germapropadiene15 4 yielded the four- and five-membered heterocycles 5 and 6 (Equation (13)).1... 

Several triphenylgermanium hydrides have been prepared where the hydride atom is encapsulated by substituents on the phenyl ligands,95,108-111 as illustrated in Equations (84)-(86).110,111 The germanium atom of 42a-c are formally hexacoordinate and that of 43 is heptacoordinate. A tribenzobarellenegermane compound with a trihydro-germane moiety attached to the bridgehead carbon was prepared and characterized (Equation (87)), and this species was found to be exceptionally air stable.1... 

Germylene 185 can be reduced with substoichiometric amounts of KCg to give the cyclotrigermenyl radical 186, which has been structurally characterized (Equation (329)), while reaction of 185 with an excess (2 equiv.) of KC8 produces 187 which is the germanium analog of the allyl anion (Equation (330)).400 The structure of 187 has been obtained as well. 

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