The crystal and molecular structure of 2,2',4,4',6,6'-hexamethyldiphenyl sulphone (dimesityl sulphone)

In Situ EXAFS‐Derived Mechanism of Highly Reversible Tin Phosphide/Graphite Composite Anode for Li‐Ion Batteries

“…EXAFS Modeling: All EXAFS data were aligned, merged, and normalized in Athena from the IFEFFIT suite. [33,34] The built-in AUTOBK algorithm was used to minimize background below R bkg = 1.0 Å. EXAFS data of OCV and lithiated/delithiated states merged from 8-16 scans, were modeled in Artemis using FEFF6 theoretical models for metallic β-Sn metal, [25] SnO 2 , [24] Sn 4 P 3 , [21] and quick first shell theory for SnLi paths. [14] All data were fitted in k, k 2 , and k 3 weighting over a k-range of 2 to 11 Å −1 and an R range of 1 to 4 Å with the Sn 4 P 3 model or 1-3 Å without Sn 4 P 3 .…”

“…EXAFS Modeling of Pristine Material at OCV: For OCV, five paths were used in modeling the pristine Sn 4 P 3 including two SnP paths and two SnSn paths composing a simplified model of the Sn 4 P 3 crystal structure, [21] and one SnO path from the shortest path of the SnO 2 crystal structure. [24] For the next three states, another SnSn path that is shorter than the typical paths in metallic Sn appears, [25] indicating the formation of metallic Sn clusters. Only minor changes are observed in the distances of all these paths until the second delithiation.…”

Conformational Studies by Dynamic NMR. 80.1 Cog-Wheel Effect in the Stereolabile Helical Enantiomers of Dimesityl Sulfoxide and Sulfone

“…The greater multiplicity detected in the solid-state NMR spectrum is a consequence of the molecular symmetry not being coincident with the site symmetry of the crystal, a feature which makes the two mesityl rings diastereotopic . The space group Pbca of crystalline 4 , in fact, has 2-fold symmetry axes not coincident with the C 2 axis of the molecule . This also accounts for the six lines spectrum (one of these peaks has a triple intensity due to the accidental coincidence of three signals) exhibited by the eight quaternary ring carbons (Table ): four equally intense lines would have been observed had molecular and site symmetry been coincident.…”

Conformations of Bridged Diphenyls. XI. Crystal Structure of 2-(4′-Carbomethoxy-2′-nitrophenylsulfonyl)-1,3,5-trimethylbenzene

“…The structures of 4,4'-dichlorodiphenyl sulfone (5) and 4,4'-diaminodiphenyl sulfone (6) are consistent with the predictions made by Koch and Moffit. However, in 2,2',4,4',6,6'hexamethyldiphenyl sulfone (7) steric hindrances between the four ortho substituents lead to a twist conformation with dihedral angles near 55". 'Author to whom all correspondence should be addressed.…”