PDF Publication Title:
Text from PDF Page: 151
Homoatomic Sulfur Cations 141 Fig. 3 Optimized geometries and relative energies of all true S42+ minima at the B3PW91 level of theory [21] 5.2.2 S42+ Isomers Due to the high local D4h symmetry it appeared simple to obtain reliable quantum chemical results not only on the structure but also on the energet- ics of the S42+ dication. It was shown, however, that especially the calculation of S42+ required great care and the highest level of theory available in order to obtain reliable results (see thermodynamics section) [20]. From this pub- lication also followed that the only affordable and comparably fast computa- tional technique for the correct structural and energetic description of sulfur homopolyatomic cations is the hybrid HF-DFT level B3PW91 and its newer modified version MPW1PW91. In the following, therefore, the potential en- ergy surface of the gaseous S42+ dication was examined with the B3PW91 method and this investigation revealed the presence of at least five local minima (Fig. 3) [21]. From Fig. 3 it is clear that, as in the solid state, square planar S42+ (A) is the global minimum of all assessed isomers. It should be noted though that the second favorable isomer B has an unexpected non-classical highly p and p*-p* bonded structure and only the next all s bonded isomer C with a high relative energy of +155 kJ mol1 has a classically expected geometry with the tricoordinate sulfur atoms formally bearing the positive charge. 5.2.3 Exo-Endo S82+ MP2, B3LYP, BLYP, BP86, and HF levels were unsuccessfully [22] employed to optimize the geometry of isolated S82+ dication. By contrast, the B3PW91 and MPW1PW91 levels for the first time led to a geometry of gaseous S82+ similar to solid S82+ in S8(AsF6)2 including the three long transannular con-PDF Image | Topics in Current Chemistry
PDF Search Title:
Topics in Current ChemistryOriginal File Name Searched:
Elemental-Sulfur-und-Sulfur-Rich-Compounds-I.pdfDIY PDF Search: Google It | Yahoo | Bing
Sulfur Deposition on Carbon Nanofibers using Supercritical CO2 Sulfur Deposition on Carbon Nanofibers using Supercritical CO2. Gamma sulfur also known as mother of pearl sulfur and nacreous sulfur... More Info
CO2 Organic Rankine Cycle Experimenter Platform The supercritical CO2 phase change system is both a heat pump and organic rankine cycle which can be used for those purposes and as a supercritical extractor for advanced subcritical and supercritical extraction technology. Uses include producing nanoparticles, precious metal CO2 extraction, lithium battery recycling, and other applications... More Info
| CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com | RSS | AMP |