Carbon chains are the dominant architectural scheme of interstellar molecular chemistry. The cyano radicals C3Nand C5N, for example, have been detected in the late type star IRC+10216 and in the molecular cloud TMC-1; C3N also in IRAS 15194-5115, TMC-2, HCL 2, CRL618, and CRL2688 ([1], Appendix D). Other cyano radicals like C2N with a much smaller dipole moment have not been observed so far. The astronomical detection of these species depends strongly on the knowledge of their transition frequencies obtained by laboratory work. Longer CnN chains or isotopomers of CnN are difficult to observe in the laboratory and very sensitive spectrometers are required to detect their transition frequencies.