Polycondensation of acetylide by coordination catalysis to α or β-carbyne

Synthesis of carbyne by oxidation polycondensation of dicopper acetylide with Cu~(1+) and Cu~(2+) coordination as catalysis was studied by FTIR, DSC and SEM. It is found that Cu~(2+) palys a key role in the synthesis of carbyne. The one step synthesis by oxidation polycondensation of acetylene led to a mixture of α- and β-carbyne while the two step synthesis (The frist step, dicopper acetylide synthesized from acetylene and the second step, carbyne synthesized from dicopper acetylide) can produce β- or α-carbyne, depending on the anions in the catalysts used. In case of hard base, such as Cl~- β-carbyne is obtained while in case of a soft ligand, such as CN~-, α-carbyne is obtained. β-carbyne can been transformed into α-carbyne at 250?℃ and two-step synthesized carbynes are nano particles. A mechanism for the oxidation polycondensation of acetylide is proposed.