ABSTRACT
The synthetic approach presented here is a development of our earlier observation that dicopper acetylide (Cu2C2) and dicopper diacetylide (Cu2C4), left to age in humid air, undergo a slow coupling reaction [1-3]. The coupling reaction is the well-known Glaser reaction, an oxidative carbon-carbon bond formation of acetylenic species mediated by copper ions [4]. When copper acetylide or dicopper acetylide are hydrolyzed with hydrochloric acid, they release polyynes in an extracting hydrocarbon medium [1-3] and a carbonaceous residue containing carbynoid structures [5-7]. The drawback of the described synthetic approach involved the handling of almost dry and more or less aged dicopper acetylide and dicopper diacetylide, both proven to be explosive. Instead, the synthetic approach proposed in this chapter is completely safe because the acetylides are formed in situ in an aqueous solution. When dispersed in water solution the acetylides are completely safe and not explosive. They are oxidized and hydrolyzed, always in water solution in a completely safe procedure, which is in contrast to
our old approach, which involved necessarily the isolation of the acetylides. Furthermore, in Chapter 18 we have shown that the polyynides, i.e. the copper salts of polyynes, are already much less explosive and dangerous than the corresponding acetylides.
