Organic Polyynes

Figure 6.2 Comparison of the optical-limiting response of P26 and its purely organic polyyne (T = 82%).

Cataldo, F. Synthesis of polyynes in a submerged electric arc in organic solvents. Carbon 2004, 47, 129-142. 

The approach to form carbon ring molecules from organic precursors has been extended to produce three-dimensional macrocyclic polyynes of larger sizes (Section 6.4). Despite the fragility and explosive reactivity, the precursory molecules containing polyyne structures are successfully isolated and well characterized. The liberated pure carbon molecules have been... 

In this chapter, keeping in mind the generation, characterization, and reactions of the cyclic polyynes, the interplay of organic chemistry and carbon cluster science during the last decade is presented. First, following short historical remarks (Section 6.2.1), recent research activity on the production of cyclo[ ]carbons from well-defined organic precursors is surveyed (Section 6.2.2). Second, major structural and electronic properties of mono-cyclic carbon clusters are presented in the context of theoretical considerations (Section 6.2.3), followed by observational results of photoelectron spectroscopy (Section 6.2.4). Third, considerations on the infrared activity of cyclic Cio will be presented (Section 6.2.5). Finally, this chapter ends with experimental as well as theoretical proposals for the structures of multicyclic polyynes (Section 6.3) and their relevance to the formation of fullerenes, in particular from polycyclic polyynes (Section 6.4). 

We have recently studied laser ablation of graphite and Ceo particles suspended in solutions [6,7]. It was found that hydrogen-capped polyynes (C2 H2 = 4-8) were produced from graphite particles suspended in benzene, toluene, or hexane solution [6], while C2 H2 (n = 4-6) polyynes were formed from Cgo in hexane or methanol solution [7]. Cataldo [8,9] has recently synthesized C2 H2 (n = 2-9) polyynes by a submerged electric arc discharge in organic solvents. 

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