Purification of polyynes via carbides.

The synthesis of carbyne has remained an elusive goal for decades. One of the significant reasons is that high-purity and high-concentration hydrogen end-capped polyynes (C 2n H 2) as the most important model molecule and precursors for carbyne have been not widely prepared. Herein, we develop a facile and universal strategy to obtain high-purity and high-concentration C 8 - 18 H 2 molecules using solid linear carbon chains with silver atom ending-capped (Ag 2 C 8-18) as reaction precursors. The purified and concentrated C 8 - 18 H 2 solution and Ag 2 C 8-18 powder are evaluated by a combination of X-ray photoelectron spectroscopy, nuclear magnetic resonance spectroscopy, Raman spectroscopy, UV–vis–NIR spectroscopy and transmission electron microscope. These results confirm that the high-purity and high-concentration C 2n H 2 are obtained through the reaction of metal carbides solid and hydrogen chloride molecule. Our strategy for investigating unprotected linear carbon chains in solid and the successful preparation of high-concentration C 2n H 2 from solid carbides provide a new avenue for the research of linear carbon chains. [Display omitted] [ABSTRACT FROM AUTHOR]