Infrared absorption of GeNNO isolated in solid Ar.

Codeposition of thermally generated atomic germanium vapor and nitrous oxide (N(2)O) in Ar onto a substrate at 11 K produced infrared absorption lines in several sets. The most prominent comprises intense lines at 1443.7, 1102.4, and 784.0 cm(-1) that become diminished upon irradiation with UV or visible light. These lines are attributed to nu(1) (NO stretching), nu(2) (NN+GeN stretching), and nu(3) (NNO bending+NN stretching) modes of singlet GeNNO. Two additional weak features at 1238.1 and 2859.2 cm(-1) are assigned as nu(3)+nu(4) and 2nu(1) of GeNNO, respectively. Weak doublet features at 1259.3/1255.5 and 1488.9/1486.4 cm(-1) are tentatively assigned to nu(2) of triplet GeONN and nu(1) of singlet cyc-Ge-eta(2) [NN(O)], respectively. Quantum-chemical calculations on the Ge+N(2)O system with density-functional theory (B3LYP /aug-cc-pVTZ) predict five stable structures: GeNNO (singlet and triplet), singlet cyc-Ge-eta(2) [NN(O)], triplet cyc-Ge-eta(2) (NNO), GeONN (singlet and triplet), and singlet GeNON. Vibrational wavenumbers, relative IR intensities, and (15)N-isotopic ratios for observed species are consistent with those computed. Irradiation of singlet GeNNO with lambda=248 or 193 nm or lambda>525 nm yields GeO.