TY - JOUR
T1 - Basicity of nitrogen-sulphur(vi) compounds. Part 6.1ionization of NN'-di-and N-mono-substituted sulphamides and dihydro-2,1,3-benzothiadiazoline and benzothiadiazine 2,2-dioxides (cyclic sulphamides)
AU - Burke, Padraig O.
AU - McDermott, Séan D.
AU - Hannigan, Thomas J.
AU - Spillane, William J.
PY - 1984
Y1 - 1984
N2 - 36 Di-and mono-and two tri-substituted sulphamides have been synthesised and their ionization equilibria in base (Schemes 1—3) have been studied. Many of the sulphamides are new materials. The pKavalues obtained for each series have been correlated in Hammett and Taft plots. The Hammett p values obtained for the ionization of the proximate hydrogen are ca. 2.3. The Taft ρ⋆ value obtained for ionization of the ‘remoter’ hydrogen is 1.68. The six-membered cyclic sulphamides are more acidic than their acyclic analogues by ca. 2.5 pKaunits and the five-membered cyclic sulphamides are ca. 4 pKaunits more acidic than model open-chain counterparts. Sulphur o’-orbital involvement and ring-strain are suggested as possible sources of this acid-strengthening’ effect.
AB - 36 Di-and mono-and two tri-substituted sulphamides have been synthesised and their ionization equilibria in base (Schemes 1—3) have been studied. Many of the sulphamides are new materials. The pKavalues obtained for each series have been correlated in Hammett and Taft plots. The Hammett p values obtained for the ionization of the proximate hydrogen are ca. 2.3. The Taft ρ⋆ value obtained for ionization of the ‘remoter’ hydrogen is 1.68. The six-membered cyclic sulphamides are more acidic than their acyclic analogues by ca. 2.5 pKaunits and the five-membered cyclic sulphamides are ca. 4 pKaunits more acidic than model open-chain counterparts. Sulphur o’-orbital involvement and ring-strain are suggested as possible sources of this acid-strengthening’ effect.
UR - http://www.scopus.com/inward/record.url?scp=37049091457&partnerID=8YFLogxK
U2 - 10.1039/P29840001851
DO - 10.1039/P29840001851
M3 - Article
AN - SCOPUS:37049091457
SN - 1470-1820
SP - 1851
EP - 1854
JO - Journal of the Chemical Society. Perkin Transactions 2
JF - Journal of the Chemical Society. Perkin Transactions 2
IS - 11
ER -