Geometries and energy separations of electronic states of AsCl2, AsBr2, AsCl2+, and AsBr2+

Abstract

Spectroscopic properties of the low-lying 2B1, 2A1, 2A2, 4A2, 2B1(II), 4B1, 2B2(I), 2B2(II) electronic states of AsCl2 and AsBr2 have been studied with the complete active space self-consistent field (CASSCF) followed by multireference singles and doubles configuration interaction (MRSDCI) methods. In addition, the three low-lying electronic states of AsCl2+ and AsBr2+, (1A1,3B1,1B1) and the ground states of AsCl and AsBr were investigated. The bond dissociation energies of AsCl2, AsBr2, AsCl, and AsBr have been computed at the CASSCF/MRSDCI and CASSCF/second order configuration interaction (SOCI) levels as De(ClAs–Cl)=2.56 eV, De(BrAs–Br)=1.96 eV, De(As–Cl)=2.68 eV, and De(As–Br)=2.26 eV. The adiabatic ionization energies obtained in this work are 8.40 eV for AsCl2 and 8.33 eV for AsBr2. All these species have been found to possess bent geometries at their ground electronic states.

Franck–Condon simulation of the photoelectron spectrum of AsCl2 and the photodetachment spectrum of AsCl employing UCCSD(T)‐F12a potential energy functions: IE and EA of AsCl2

“…15 As shown in Table 6, the most complete set of computational studies previously available on the PnCl 2 compounds are the MRSDCI calculations by Latifzadeh and Balasubramanian on PCl 2 , 39 AsCl 2 , 13 and SbCl 2 . 41 In addition, G2 38 and DFT (see footnotes c and d of Table 6 for details) 40 calculations have also been carried out on PCl 2 and its cation and anion, and an experimental value is available for the EA of PCl 2 .…”

“…[4][5][6] However, to our knowledge, there was only one ab initio study on low-lying electronic states of AsCl 2 and its cation, which reported a calculated IE for AsCl 2 in 1997. 13 This is a CASSCF/MRSDCI investigation, which employed a relativistic effective core potential (RECP) and a contracted valence [3s3p2d] basis set for As. It gives a computed IE value of 8.40 eV for AsCl 2 , which is considerably smaller than available, experimentally derived, values of between 9.1 and 12.7 eV 10,11 discussed above.…”

Ab Initio Studies of the Contrasting Butadiene Cheletropic and Diels−Alder Cycloaddition Reactivities Observed for “Carbenic” Phosphorus (Phosphenium) and Arsenic (Arsenium) Cations

“…Several topical quantum-chemical studies of ylidenes 1 have provided substantial insight into their structure and bonding. − Electronic structure models have also been established for the group 15 carbene analogues 2 , − which indicate that most, including those possessing adjacent π-electron-donor substituents, have a singlet ground state ([NH 2 ] + is an exception) . In this context, we have performed full geometry optimizations and frequency calculations at the HF/6-311G* level of theory for model cations 3 and 7 with singlet ( C 2 symmetry) and triplet ground states ( C 1 , C 2 , C s , and C 2 v symmetries).…”

AsCl radical: The low-lying electronic states and the (1)3Π →X 3Σ− electronic transition

“…These orbitals were further optimized using the state-averaged complete active space self-consistent field (SA-CASSCF) method [21,22]. The SA-CASSCF (8,8) function was formed correlating only the 4p 3 electrons of As and the 3p 5 electrons of Cl. These eight electrons were distributed into an active space of eight orbitals (4a 1 , 2b 1 and 2b 2 within C 2v point group), corresponding to the (5), (12), (6), (13), (14) and (15) MOs.…”

“…Halogen etching of group's 13-15 semiconductors, such as GaAs and InP, is also technologically important in the fabrication of microelectronic devices. Species containing halogen such as AsX 3 , AsX 2 and AsX (X is the halogen element) radicals are known to be produced during the etching of GaAs with halogen gases upon photoexcitation of AsX 3 [8].…”