Ab initio Hartree–Fock–Slater calculations of polysulfanes H₂S_n (n = 1–4) and the ions HS and S

Abstract

AbstractsAn ab initio Hartree-Fock-Slater procedure was applied to the calculation of the electronic structure of polysulfanes, H2S, ( n = 1-4) and the ions HS, and Si-. Charge densities, overlap populations, and deprotonation energies are calculated; the latter appear well correlated with the first and second acidity constants.On a employe une mtthode Hartree-Fock-Slater a6 inirio pour le calcul de la structure electronique des polysulfanes H2S, ( n = 1-4) et les ions HS, et Si-. On a calculi les densittsde charge, les populations de recouvrement et les energies de deprotonation; ces dernieres semblent en bon accord avec les premieres et deuxitmes constants d'aciditt.Ein Hartree-Fock-Slater-Verfahren von ab-initio-Type is fur die Berechnung der Elektronenstruktur der Polysulfanen, H2S, ( n = 1-4) und der Ionen HS, und S i -angewandt worden. Ladungsdichten, Uberlappungspopulationen und Deprotonierungsenergien wurden berechnet. Die letzten scheinen mit den ersten und zweiten Aciditatskonstanten gut korreliert zu sein.

Halide‐Free Synthesis of Hydrochalcogenide Ionic Liquids of the Type [Cation][HE] (E=S, Se, Te)

“…The amount of hydrosulfide is slightly reduced if the reaction is continued for 72 h, but the phosphonium cation starts to decompose as well. These results concur with calculations that the disulfide dianion S 2 2− is in principle unstable and is only stabilized in inorganic salts with a sufficiently high lattice energy. The only structurally proven instance in which an isolated S 2 2− ion was observed alongside organic molecules is the co‐crystallization of a potassium 1,1‐dithiolate with one third of dipotassium disulfide .…”

“…The amount of hydrosulfide is slightly reduced if the reactioni s continued for 72 h, but the phosphonium cation starts to decompose as well. These results concur with calculations that the disulfide dianion S 2 2À is in principle unstable [46] and is only stabilized in inorganic salts with as ufficiently high lattice energy.T he only structurallyp roveni nstance in whicha ni solated S 2 2À ion was observed alongside organic molecules is the co-crystallization of ap otassium 1,1-dithiolate with one third of dipotassium disulfide. [47] Without any doubt, Scheme 5a nd similarp ublished equations [13] of such sulfur redox chemistry with HS À are an ideal pictureo ft he scenario, which is never reached for organic cations ands maller polysulfide chains.…”

Chemistry of Iron Sulfides

“…The charges indicated on the S atoms are from the extended Hu ¨ckel calculations 71 for S n where n ) 2-8. They are in reasonable agreement with the charges from the ab initio calculations 55 for n ) 1-4.…”

“…Figure 5 shows the molecular orbital and the charges from ab initio calculations. 55 Because the LUMO is an antibonding orbital in the bent H 2 S molecule, it is more destabilized relative to similar molecular orbitals for linear molecules such as BeH 2 . 50 Because of this destabilization, electrons added to this LUMO orbital cause a weakening of both S-H bonds.…”

Ab initio Hartree–Fock–Slater calculation of Tetrathiafulvalene (TTF) and the TTF1+ and TTF2+ ions

“…All calculations reported are single determinant and of the spin restricted type. The atomic basis set employed is the double-zeta set optimized by Clementi and Roetti [26] augmented with a 3d (exponent 1.71) STO for sulfur [20] and two 1s orbitals (exponents 1.0 and 1.4) for hydrogen [23]. The atomic core orbitals, 1s' for carbon and ls22s22p6 for sulfur, were kept frozen in the manner described by Baerends et al [ll].…”