The surprising metastability of TeH2+.
J Chem Phys
; 138(22): 224309, 2013 Jun 14.
Article
em En
| MEDLINE
| ID: mdl-23781797
A high-level ab initio investigation of a manifold of electronic states of the diatomic dication TeH(2+) is presented. Potential energy curves for both Λ + S and relativistic (Ω) states are constructed not only making evident the metastability of this system, but also the large energy splitting due to spin-orbit interactions. This effect is also very significant in the region close to the crossing of the (2)Π and (4)Σ(-) states, where avoided crossings between the Ω states have a relatively large impact on the height of the energy barriers. In contrast to TeH, with only two bound states (X1 (2)Π3∕2 and X2 (2)Π1∕2) below about 25,000 cm(-1), in the case of TeH(2+) a much richer energy profile is obtained indicating various possibilities of electronic transitions. Guided by the results of this study, the experimental characterization of these states is now a challenge to spectroscopists. Since close to the equilibrium region the double positive charge is centered on the tellurium atom, the binding in this system can be rationalized as a simple covalent bond between the pz and s orbitals of Te(2+) and H, respectively. As the internuclear distance increases, the electron affinity of Te(2+) overcomes that of H(+) and the system dissociates into two singly charged fragments. A simulation of the double ionization spectra complements the characterization of the electronic states, and results of a mass spectrometric investigation corroborates the predicted transient existence of this metastable species.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
J Chem Phys
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Estados Unidos