ISSN:
1434-1948
Keywords:
Sulfur
;
Sulfanes
;
Acidity
;
Ab initio MO calculations
;
Hyperconjugation
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The gas-phase acidities ΔGacid(298 K) of the sulfanes H2Sn (n = 1-4) have been calculated by ab initio molecular orbital theory using the G2 and G2(MP2) methods, which were applied to the geometries of lowest energy. The results show that the higher sulfanes are surprisingly strong proton donors. The acidities (in kJ mol-1) are as follows: H2S (1444), H2S2 (1406), H2S3 (1370), H2S4 (1347). The latter three values may be compared to those of other strong Brønsted acids like gaseous HNO2 (1396), HCl (1371), and HBr (1332). The monoanions HSn- exhibit an interesting bond length distribution as a consequence of the charge delocalization by hyperconjugation, which in turn may be responsible for the high acidities of the sulfanes.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
