ISSN:
1572-9001
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Ab initio molecular orbital theory with triple-zeta-valence plus polarization basis sets and with electron correlation incorporated at the fourth-order Møller-Plesset level has been used to study the tetrahydridoonium dications, OH4 2+, SH4 2+, and SeH4 2+. The tetrahydridoselenonium dication SeH4 2+ is predicted to have a tetrahedral (T d )structure, similar to OH4 2+ and SH4 2+, with short bonds to hydrogen (1.483 Å). Although deprotonation of SeH4 2+ is thermodynamically favored Cby 104 kJ mol−1), such a reaction is inhibited by a large barrier (240kJmol−1]. Thus, SeH4 2+ lies in a deep potential well and as an isolated species should have a long lifetime in the gas phase. The estimated heat of formation, ΔH° f , for SeH4 2+ is very high (2483 kJ mol−1], as is the case for OH4 2+ and SH4 2+. Of the group IV onium dications (OH4 2+, SH4 2+, and SeH4 2+), SeH4 2+ displays the greatest kinetic and thermodynamic stability toward proton loss. Substantial solvent stabilization is required in order to generate SeH4 2+ in solution.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00675779
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