TY - JOUR
T1 - Bis(benzimidazolium)methane salts
T2 - A potential guest for dibenzo-24-crown-8 towards [2]pseudorotaxanes
AU - Ghosh, Sabari
AU - Schmiedekamp, Ann Marie
AU - Mukhopadhyay, Chhanda
N1 - Funding Information:
One of the authors (S.G.) thanks the University Grants Commission, New Delhi, for her fellowship (SRF). We thank Professor Amarendranath Patra of Department of Chemistry, University of Calcutta. We thank the CAS Instrumentation Facility, University of Calcutta for spectral data. The authors acknowledge computer use of the Lion-X series of computational clusters of the Research Computing and Cyber infrastructure group, a unit of Information Technology Services at Penn State University. We also acknowledge grant received from UGC funded Major project, F. No. 37-398/2009 (SR) dated 11-01-2010. We also wish to thank Chembiotek, a TCG Lifesciences Enterprise for variable temperature NMR experiments.
Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2012/11/25
Y1 - 2012/11/25
N2 - We investigated the threading of bis(benzimidazolium) methane moieties with DB24C8 at 35°C (room temperature) and found a high degree of association. The presence of threaded complexes was determined by 1H NMR and also supported by high resolution mass spectrometry and B3LYP/6- 31G**++calculations. A 2D NMR study was done to elucidate the host-guest geometry and the molecular interactions present. The variable temperature NMR experiment was done over a temperature range of 243-323 K. The threading was stable and visible even at 323 K. Acid-base equilibrium established the reversibility of the process. DFT optimized structures establish that two H-bonded links are present between O 1⋯O 4′ and O 3⋯O 2′ across the dibenzo axis of the crown.
AB - We investigated the threading of bis(benzimidazolium) methane moieties with DB24C8 at 35°C (room temperature) and found a high degree of association. The presence of threaded complexes was determined by 1H NMR and also supported by high resolution mass spectrometry and B3LYP/6- 31G**++calculations. A 2D NMR study was done to elucidate the host-guest geometry and the molecular interactions present. The variable temperature NMR experiment was done over a temperature range of 243-323 K. The threading was stable and visible even at 323 K. Acid-base equilibrium established the reversibility of the process. DFT optimized structures establish that two H-bonded links are present between O 1⋯O 4′ and O 3⋯O 2′ across the dibenzo axis of the crown.
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U2 - 10.1016/j.tet.2012.08.080
DO - 10.1016/j.tet.2012.08.080
M3 - Article
AN - SCOPUS:84867508779
VL - 68
SP - 9826
EP - 9835
JO - Tetrahedron
JF - Tetrahedron
SN - 0040-4020
IS - 47
ER -