The Gas Phase Acidities of the Sulfanes H2Sn (n = 1–4)

✍ Scribed by André H. Otto; Ralf Steudel

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 237 KB
• Volume: 1999
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/(sici)1099-0682(199911)1999:11<2057::aid-ejic2057>3.0.co;2-p

✦ Synopsis

The gas-phase acidities ∆G acid (298 K) of the sulfanes H 2 S n may be compared to those of other strong Brønsted acids like gaseous HNO 2 (1396), HCl (1371), and HBr (1332). The (n = 1-4) have been calculated by ab initio molecular orbital theory using the G2 and G2(MP2) methods, which were monoanions HS n -exhibit an interesting bond length distribution as a consequence of the charge delocalization by applied to the geometries of lowest energy. The results show that the higher sulfanes are surprisingly strong proton hyperconjugation, which in turn may be responsible for the high acidities of the sulfanes. donors. The acidities (in kJ mol -1 ) are as follows: H 2 S ( ), H 2 S 2 ( ), H 2 S 3 (1370), H 2 S 4 (1347). The latter three values industry the H 2 S must be extracted by treatment with etha-[ ] Part 208: R. Steudel, K. Hassenberg, J. Pickard, Organometallics, C 2 ; the enantiomer has the motif Ϫ Ϫ) or ϩ Ϫ (identical in press. [a] Institut für Anorganische und Analytische Chemie, Sekr. C2, to motif Ϫ ϩ; both are of C s symmetry).