The structure, stability, and infrared spectrum of B2N, B2N+, B2N−, BO, B2O and B2N2

Abstract

Abstract The structure, infrared spectrum, and heat of formation of B2N, B2N−, BO, and B2O have been studied ab initio. B2N is very stable; B2O even more so. B2N, B2N−, B2O, and probably B2N+ have symmetric linear ground-state structures; for B2O, an asymmetric linear structure lies about 12 kcal/mol above the ground state. B2N+, B2N− and B2O have intense asymmetric stretching frequencies, predicted near 870, 1590 and 1400 cm−1, respectively. Our predicted harmonic frequencies and isotopic shifts for B2O confirm the recent experimental identification by Andrews and Burkholder. Absorptions at 1889.5 and 1998.5 cm−1 in noble-gas trapped boron nitride vapor belong the BNB and BNBN (3Π), respectively; a tentative assignment of 882.5 cm−1 to BNB+ is proposed. Total atomization energies Σ De (Σ D0) are computed (accuracy ±2 kcal/mol) as: BO 193.1 (190.4), B2O 292.5 (288.7), B2N 225.0 (250.3) kcal/mol. The ionization potential and electron affinity of B2N are predicted to be 8.62±0.1 and 3.34±0.1 eV. The MP4-level additivity approximations involved in G1 theory results in errors on the order of 1 kcal/mol in the Σ De values.