The ethynyl radical (systematically named λ3-ethyne and hydridodicarbon(C—C)) is an organic compound with the chemical formula C≡CH (also written [CCH] or C 2H). It is a simple molecule that does not occur naturally on Earth but is abundant in the interstellar medium. It was first observed by electron spin resonance isolated in a solid argon matrix at liquid helium temperatures in 1963 by Cochran and coworkers at the Johns Hopkins Applied Physics Laboratory. It was first observed in the gas phase by Tucker and coworkers in November 1973 toward the Orion Nebula, using the NRAO 11m radio telescope. It has since been detected in a large variety of interstellar environments, including dense molecular clouds, bok globules, star forming regions, the shells around carbon-rich evolved stars, and even in other galaxies.

CAS：2122-48-7
中文别名：
英文别名：Ethynyl radical;Acetylenyl-Radical;acetylene radical;Ethynyl;Ethinyl-Radikal;Acetylenradikal;ethyne;acetylenyl;
分子式：C2H
分子量：25.0293
精确质量：25.0078
Psa：0.0
Logp：0.1264