Homoleptic Organocopper Compounds CunRn

On the basis of this information, techniques for the synthesis of pure copper compounds were developed. The following parameters played an important role  

It is consequently not possible to give one general synthetic procedure (for a detailed discussion see refs. 29 and 45). It also became evident that the order of addition of the reagents can play a crucial role, which is nicely illustrated by the following examples. 

The stabilizing effect of additional donor molecules is nicely illustrated by the increase in decomposition temperatures seen on going from MeCu ( —15 °C) to CuMe(PPh3)3, which decomposes at about 75 °C [49]. The structure of the latter compound in the solid state (see Fig. 1.5) comprises a mononuclear complex with 

Another illustration of the stabilizing effect of phosphines is supplied by cyclo-pentadienylcopper triphenylphosphine, one of the very few examples in which a cyclopentadienyl group is t -bonded to copper (see Fig. 1.6) [52]. 

As mentioned above, one of the thermal decomposition pathways of alkylcopper compounds involves a j8-hydrogen elimination process, and so it is not surprising that the first well characterized alkylcopper compounds lacked such yS-hydrogens. Treatment of LiCH2SiMe3 with Cul afforded a tetrameric aggregate, the structure of which was unambiguously proven by an X-ray crystal structure determination (see Fig. I.IB in the previous section). This represented the first example of a well characterized alkylcopper compound [17]. 

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