Infrared absorption of GeNNO isolated in solid Ar

Abstract

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 v(1) (NO stretching), v(2) (NN+GeN stretching), and v(3) (NNO bending + NN stretching) modes of singlet GeNNO. Two additional weak features at 1238.1 and 2859.2 cm(-1) are assigned as v(3) + v(4) and 2v(1) of GeNNO, respectively. Weak doublet features at 1259.3/1255.5 and 1488.9/1486.4 cm(-1) are tentatively assigned to v(2) of triplet GeONN and v(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. (C) 2009 American Institute of Physics. [doi:10.1063/1.3236384]