15min:

MARILYN E. JACOX AND WARREN E. THOMPSON, Optical Technology Division, National Institute of Standards and Technology, Gaithersburg, MD 20899-8441.

When a very dilute mixture of NCCN in neon is codeposited at 4.3 K with a beam of neon atoms that have been excited in a microwave discharge, prominent infrared absorptions of the uncharged isomers CNCN and CNNC appear in the resulting solid. The ₃ absorption of NCCN⁺ is also very prominent, and the ground-state ₁ + ₃ absorption of that product is observed for the first time. Photoisomerization to CNCN⁺, for which the two CN-stretching fundamentals are identified, occurs in the red spectral region, and photodestruction of both NCCN⁺ and CNCN⁺ occurs in the near ultraviolet. The photochemistry of these two cations is correlated with recently published results of experimental and quantum chemical studies of their electronic energy levels.