NMR studies of anion-induced conformational changes in diindolylureas and diindolylthioureas
NMR studies of anion-induced conformational changes in diindolylureas and diindolylthioureas
The conformational properties of 1,3-diindolylureas and thioureas were studied by a combination of heteronuclear NMR spectroscopy and quantum mechanics calculations. NOE experiments showed that the anti–anti conformer along the C7–N7? bonds was predominant in DMSO-d6 solution in the absence of anions. Anion-induced changes in the 1H and 15N chemical shifts confirm the weak binding of chloride anions with negligible conformational changes. Strong deshielding of ureido protons and moderate deshielding of indole NH was observed upon the addition of acetate, benzoate, bicarbonate and dihydrogen phosphate, which indicated that the predominant hydrogen bond interactions occurred at the urea donor groups. Binding of oxo-anions caused conformational changes along the C7–N7? bonds and the syn–syn conformer was preferred for anion–receptor complexes. The conformational changes upon anion binding are in good agreement with energetic preferences established by ab initio calculations.
anion recognition, conformation analysis, host–guest systems, nmr spectroscopy
1205-1214
Makuc, Damjan
0587d709-5f7a-44c7-9b74-1940285b933d
Hiscock, Jennifer R.
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Light, Mark E.
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Gale, Philip A.
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Plavec, Janez
7a5f325c-d357-40b2-87ab-7482f862b7f0
2 September 2011
Makuc, Damjan
0587d709-5f7a-44c7-9b74-1940285b933d
Hiscock, Jennifer R.
99a8a34c-a869-48e2-b713-1e69e4741032
Light, Mark E.
cf57314e-6856-491b-a8d2-2dffc452e161
Gale, Philip A.
c840b7e9-6847-4843-91af-fa0f8563d943
Plavec, Janez
7a5f325c-d357-40b2-87ab-7482f862b7f0
Makuc, Damjan, Hiscock, Jennifer R., Light, Mark E., Gale, Philip A. and Plavec, Janez
(2011)
NMR studies of anion-induced conformational changes in diindolylureas and diindolylthioureas.
Beilstein Journal of Organic Chemistry, 7, .
(doi:10.3762/bjoc.7.140).
Abstract
The conformational properties of 1,3-diindolylureas and thioureas were studied by a combination of heteronuclear NMR spectroscopy and quantum mechanics calculations. NOE experiments showed that the anti–anti conformer along the C7–N7? bonds was predominant in DMSO-d6 solution in the absence of anions. Anion-induced changes in the 1H and 15N chemical shifts confirm the weak binding of chloride anions with negligible conformational changes. Strong deshielding of ureido protons and moderate deshielding of indole NH was observed upon the addition of acetate, benzoate, bicarbonate and dihydrogen phosphate, which indicated that the predominant hydrogen bond interactions occurred at the urea donor groups. Binding of oxo-anions caused conformational changes along the C7–N7? bonds and the syn–syn conformer was preferred for anion–receptor complexes. The conformational changes upon anion binding are in good agreement with energetic preferences established by ab initio calculations.
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Published date: 2 September 2011
Keywords:
anion recognition, conformation analysis, host–guest systems, nmr spectroscopy
Organisations:
Organic Chemistry: Synthesis, Catalysis and Flow
Identifiers
Local EPrints ID: 196995
URI: http://eprints.soton.ac.uk/id/eprint/196995
ISSN: 1860-5397
PURE UUID: feb20f36-920d-487b-b3d5-489111674292
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Date deposited: 16 Sep 2011 08:14
Last modified: 15 Mar 2024 03:06
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Contributors
Author:
Damjan Makuc
Author:
Jennifer R. Hiscock
Author:
Philip A. Gale
Author:
Janez Plavec
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