Eight New Carbon Chain Molecules

Abstract

A summary is given of the laboratory measurements of the rotational spectra of eight new carbon chains: the cyanopolyynes HC11N and HC13N; the carbon chain radicals C7H, C8H, C9H, and C11H; and the cumulene carbenes H2C5 and H2C6. Measured line frequencies and derived spectroscopic constants are listed for all eight, and rest frequencies for the astronomically important transitions that are not easily calculated are tabulated. With our laboratory measurements, four of the new carbon chains have already been detected in at least one astronomical source; the remaining four should be detectable with existing large centimeter- or millimeter-wave telescopes.