Ab initio study of chemical species in the BCl3 plasma: Structure, spectra, and decomposition paths

Abstract

Industrially important plasmas offer a variety of complicated molecular processes that benefit from predictive quantum chemical techniques. Ab initio coupled-cluster and MBPT methods are used to characterize structures, vibrational frequencies, ionization potentials, electron affinities, and excited states for the main fragments in the BCl3 plasma, i.e. BCl3, BCl2, BCl, and their anions and cations for which few experimental results exist. The excited, electron attached, and ionized states are calculated by employing the equation-of-motion coupled cluster (EOM-CC) method. Recent results from a photofragmentation study and an electron collision experiment are analysed based on the calculated results. Some features of the potential energy surfaces of excited states of BCl2 are discussed in order to explain the origin of the experimental fluorescence spectrum. We also consider possible microscopic processes with low energy, such as the formation and destruction of neutral and ionic species, decomposition paths, and the role of each fragment. While decomposition through transient states of BCl3− by electron attachment is the most probable path for low-energy electron attachment, decomposition through excited states of BCl3 can play a role only when there is no other way to make the BCl3+ ion.

Infrared laser velocity modulation spectrum of the ν3 fundamental band of HBBr+

“…The pathways leading to the formation of BBr can also be considered analogous to those suggested for BCl, 25,26 BBr 3 ϩe Ϫ →BBr͑A 1 ⌸ ͒ϩ2Brϩe Ϫ , ͑4͒…”

Electron Interactions With BCl3

“…27 The lowest unoccupied molecular orbital of the BCl 3 molecule is 2a 2 Љ(B 2p -Cl 3p*), and the next two higher-lying empty orbitals are 3a 1 Ј and 4eЈ (B 2p -Cl 3p*). 29,30 The presence of these unoccupied molecular orbitals helps explain the observed negative ion states of the BCl 3 molecule, and consequently the observed or calculated structure in the electron scattering and electron attachment cross sections. A detailed calculation by Baeck and Bartlett 29 -optimizing bond lengths and bond angles within D 3h symmetry for BCl 3 and C 3v symmetry for BCl 3 Ϫ -provided a number of structural and electronic parameters such as ionization energies, electronic vertical excitation energies, and vibrational frequencies for the BCl 3 , BCl 3 Ϫ , BCl 3 ϩ species.…”

“…A detailed calculation by Baeck and Bartlett 29 -optimizing bond lengths and bond angles within D 3h symmetry for BCl 3 and C 3v symmetry for BCl 3 Ϫ -provided a number of structural and electronic parameters such as ionization energies, electronic vertical excitation energies, and vibrational frequencies for the BCl 3 , BCl 3 Ϫ , BCl 3 ϩ species. 29 A number of experimental studies contribute to an understanding of the molecular and electronic structure of the BCl 3 molecule. These include electron-impact excitation and ionization, [31][32][33] negative-ion formation, [31][32][33][34][35][36][37] electron-impact dissociation into excited fragments, [38][39][40] photoelectron spectra, 28,41,42 photoionization and photodissociation, [43][44][45][46][47][48][49] and photoabsorption and fluorescence measurements in the ultraviolet/visible ͑UV/VIS͒ region.…”

Characterization of Ph‐negative abnormal clones emerging during imatinib therapy

“…At the same time, of these theoretical and experimental investigations, very few can completely describe the spectroscopic properties of the BCl(X 1 Σ + ). The extracted spectroscopic properties from these experiments9–13, 17–20 and theories8, 14–16, 21, 22 mainly focus on the spectroscopic constants ( D e , R e , ω e , ω e χ e , α e , B e , and D 0 ). Little information can be available in the literature dealing with its vibrational manifolds (vibrational levels and corresponding classical turning points, inertial rotation and centrifugal distortion constants, etc.…”