Tetrakis digermene

It is interesting that the aryl groups in tetrakis(2,6-diethylphenyl)diger-mene do not shift under the same conditions or upon thermolysis, presumably because of steric hindrance. However, upon photolysis, tetrakis(2,6-diethylphenyl)digermene dissociates to the diarylgermylene.48... 

Tetrakis(2,6-diethylphenyl)digermene 23 undergoes smooth cycloaddition with PhC CPh to yield a four-membered 1,2-digermacyclobutene ... 

Compound A was obtained from a reaction of tetrakis(2,6-diethylphenyl)digermene with an excess of DMSO in toluene. The molecular structures of both A and B were determined by single-crystal X-ray analyses (Figure 27). 

FIGURE 27. Molecular structure of the oxygenation products A and B of tetrakis(2,6-diisopropylphenyl)digermene (cf. Figure 26). Reprinted with permission from Reference 113. Copyright (1989) American Chemical Society... 

Tetrakis(2,6-diethylphenyl)digermene 3 is reportedly converted into hexakis(2,6-diethyl-phenyl)cyclotrigermane 12b on heating in solution1-). The proposed mechanism involves the dissociation of digermene 3 into two germylenes Dep2Ge 40, followed by their... 

The choice of the reducing agent is quite important. Thus, reduction of the precursor (2,6-diisopropylphenyl)trichlorogermane with Mg/MgBr2 in THF resulted in the formation of tetrakis(2,6-diisopropylphenyl)digermene instead of prismane 5. 

Masamune and coworkers subsequently reported the structure of tetrakis(2,6-diethylphenyl)digermene, isolated from the photoconversion of the corresponding cyclotrigermane (3). The Ge=Ge bond distance of 2.213 A in [2,6-Et2C6H3]2Ge=Ge[C6H3-2,6-Et2]2 is considerably shorter than that in (2) (2.347(2) A). 

A germacyclopropane with electronegative groups at the ring carbon atoms, 33, was obtained by the [1-I-2] cycloaddition reaction of tetrakis(2-/-butyl-4,5,6-trimethylphenyl)digermene with hexafluorobut-2-yne. A short C=C double bond (1.324(5) A) and a sharp C-Ge-C bond angle of 39.93(14)° were determined by X-ray analysis <2002ZFA2821>. 

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