PDF Publication Title:
Text from PDF Page: 037
Solid Sulfur Allotropes 27 Table 7 Crystal structure data of b-S8 at two temperaturesa (standard deviations are in brackets) Space group P21/cC2h5 (no. 14) P21C22 (no. 4) Six molecules per unit cell (four in ordered general positions, two in disordered pseudocen- tric sites, T>198 K), site symmetry: 1C1 Lattice parameters a (pm) b (pm) c (pm) b () Temperature (K) Reference 1092.6(2) 1085.2(2) 1079.0(3) 95.92(2) 297 [81] 1079.9(2) 1068.4(2) 1066.3(2) 95.71(1) 113 [27] a From the temperature dependence of lattice parameters a volume expansion of about 2104 K1 can be estimated Fig. 7 Unit cell of monoclinic b-S8 projected along the crystal b-axis. The twofold disor- der of one-third of the molecules is indicated [8] 2.2.1.3.3 Monoclinic g-S8 This allotrope, first described by several authors in the late nineteenth cen- tury, occurs as light-yellow, nacreous-glittering, needle-like prismatic crys- tals (for details see [8, 78]). There was some confusion in the literature about the crystallographic structure until Watanabe in 1974 reported a complete determination of the structure of g-S8 [8, 29]. The most recent and accurate structure data of chemically prepared g-S8 are those of Gallacher and Pinker- ton in 1993 [30a] and of natural g-S8 (rosickyite) are those of Meisser et al. [30b]. The “sheared penny roll” arrangement of the S8 molecules in this allo- trope (see Fig. 8), which has been presented earlier by De Haan [92], wasPDF 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 |