Über ein Bandenspektrum des Borhydrides

Ab initio investigation of the electronic structure and bonding of BH, BH−, and HBBH molecules

“…2 The diatomic boron hydride ͑BH͒, the simplest of boranes and of all stable diatomic molecules but H 2 , LiH, and BeH, was first observed in 1931 by Lochte-Holtgreven and van der Vleugel who recorded the optically allowed A 1 ⌸ ← X 1 ⌺ + and b 3 ⌺ − ← a 3 ⌸ transitions at 433 and 370 nm, respectively. 3 A considerable number of experimental works followed, mainly on the seven states X 1 ⌺ + , a 3 ⌸, A 1 ⌸, b 3 ⌺ − , CЈ 1 ⌬, B 1 ⌺ + , and C 1 ⌺ + within an energy range of about 7 eV. All available experimental results on BH are collected in Table I.…”

“…Equilibrium bond distances r e ͑Å͒, spectroscopic parameters e , e x e , e y e , a e , ␥ e , D e ͑cm −1 ͒, dipole moments ͑D͒, and energy separations T 0 ͑cm −1 ͒. Spectroscopic parameters are defined through the relation T͑ , J͒ = e ͑ +1/ 2͒ − e x e ͑ +1/ 2͒ 2 + e y e ͑ +1/ 2͒ 3 +¯+ B e J͑J +1͒ − a e ͑ +1/ 2͒J͑J +1͒ + ␥ e ͑ +1/ 2͒ 2 J͑J +1͒ +¯−D e J 2 ͑J +1͒ 2 − ␤ e ͑ +1/ 2͒J 2 ͑J +1͒ 2 +¯+ H e J 3 ͑J +1͒ 3 peared one year later when Knight et al confirmed its X 3 ⌺ g − symmetry by the electron spin resonance technique. 34 A more systematic ab initio work on B 2 H 2 was carried out by Perić et al 35 who published MRDCI ͑Ref.…”

Emission Spectroscopy of the Triplet System of the BH Radical

“…Extremely strong spectra of a 3 P transition near 27 000 cm 01 is the only known triplet BH were observed; since only the 0-0 band of the triplet system of the BH radical. This system was first observed system had previously been recorded (1,3), and then only by Lochte-Holtgreven and van der Vleugel in 1931 (1) and with low precision, the D£ Å 0 sequence was measured at more extensively analyzed and assigned as 3 S-3 P by Almy high resolution using the Fourier transform spectrometer at and Horsfall in 1937 (3). They analyzed the 0-0 band and Kitt Peak National Observatory.…”

Dunham coefficients for the X 1 Σ + ground state of BH and BD

“…X 1 R + and b 3 R À ? a 3 P band systems [6][7][8][9]. Based on the predissociation in the A 1 P state, Herzberg [10] predicted a dissociation energy of D 0 < 28 350 cm À1 for the X 1 R + ground state of BH.…”