The rodlike 1,8-dicyano-octa-1,3,5,7-tetrayne (NC10N) molecule was synthesized with UV-assisted coupling of rare-gas matrix-isolated cyanobutadiyne (HC5N) molecules. Detection of NC10N molecule was possible due to its strong orange-red (origin at 618 nm) electronic luminescence. Excitation spectra of this emission ((a) over tilde (3)Sigma(+)(u)-(X) over tilde (1)Sigma(+)(g) phosphorescence) gave access to studying the fully allowed (H) over tilde (1)Sigma(+)(u)-(X) over tilde (1)Sigma(+)(g) UV system of NC10N. The identification of observed spectral features was assisted with quantum chemical computations. Certain regularities shaping the electronic spectroscopy of NC2nN molecules have been discussed.