Germanium compounds synthesis

Whether these results will also have an impact on the theory of metallaallenes is difficult to predict at least for the compounds Cp (CO)2Mn = M = Mn(CO)2Cp, (M = Ge, Sn, Pb) a linear structure is established and also linear p-carbido complexes are known [198], Recently, a germanium compound has been synthesized which is directly comparable with 22. In this case, the starting material for the synthesis is not a monomeric base adduct, but a dimeric germylene complex which is cleaved by Na2Fe(CO)4 in pyridine to form 72 [199],... 

The state of the synthetic art in this area, in 1979, is much more satisfactory. During the past decade, several new synthetic developments have occurred such that we are closer to the point where the limitations upon synthesis of trifluoromethyl compounds are related more to stability problems in isolated cases, and are not nearly so much due to lack of widely applicable synthetic techniques. We find ourselves, for example, in a position in 1979 where the germanium compound, Ge(CF3)4, which in the past decade, was considered by many workers to be of insufficient stability to permit isolation, has been prepared by four independent methods and is known to be stable to over 100°C. Many of these new synthetic techniques have emerged from studies conducted in our laboratory at the University of Texas and previously... 

Chalcogenation of a divalent germanium compound with styrene sulfide has been examined as an alternative route to the first free germanethione Tbt(Tip)Ge = S 165142 (Scheme 32) and later on allowed the synthesis of new base-stabilized germanethiones 187 and 188156 [Eq. (37)]. Phenyl isocyanate also may serve as a sulfur source leading to 165, which was evidenced by electronic spectroscopy and underwent a subsequent [2 + 2] cycloaddition with phenyl isocyanate157 (Scheme 36). 

A different type of gas-phase chemistry has also been explored for simple germanium, tin and lead compounds, namely that induced by radiolysis. While germanium compounds have been the main targets and modeling of CVD processes the ultimate goal, radiolysis involves reactions of transient neutral and ionic species for which the overall mechanism is not always clear. On the other hand, analysis of the ultimate solid products252 obtained from radiolysis of different mixtures provides an exciting approach towards the synthesis of polymers and thin films. 

A linkage strategy was used for the solid-phase synthesis of a range of 1,4-benzo-diazepine derivatives . It was demonstrated that the germanium route is superior to the silicon route because numerous functional groups are tolerated and the demetallation using trifluoroacetic acid or bromine is easier for germanium compounds. In Scheme 52... 

In conclusion, enantioselective microbial reductions of silicon and germanium compounds containing an El-C(0)Me (El = Si, Ge) moiety El-CH(OH)Me] proved to be an efficient preparative method for the synthesis of optically active silanes, germanes, and digermanes. Furthermore, the commercially available yeast Saccharomyces cerevisiae (DHW S-3) is considered to be an efficient biocatalyst for this particular type of bioconversion. 

The synthesis and reactivity of germanium compounds containing double bonds to Si, Ge, and Sn has been a very active area of research over the past decade and has been extensively and recently reviewed. Particularly striking... 

This study demonstrates the utility of amidinate ligands for the synthesis of hypervalent silicon and germanium compounds, and also, for the synthesis of low-valent germanium compounds. In addition, surprising results with dianionic amidinate ligands [N-C(R)—NR ] at silicon centers are documented. 

Rima G., Satge J., Dagiral R., Lion C., Fatome M., Roman V, Laval J.D., Synthesis and radioprotective activity of new organosilicon and germanium compounds, Metal-Based Drugs, 1998, 5, 139-146. 

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