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Extended Cavitands of Nanoscale Dimensions
Author(s) -
Menozzi Edoardo,
Onagi Hideki,
Rheingold Arnold L.,
Rebek Julius
Publication year - 2005
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200500342
Subject(s) - chemistry , cavitand , supramolecular chemistry , nuclear magnetic resonance spectroscopy , mass spectrometry , host–guest chemistry , crystallography , spectroscopy , nanoscopic scale , stereochemistry , polymer chemistry , crystal structure , nanotechnology , chromatography , physics , materials science , quantum mechanics
Abstract New tetrabenzimidazole cavitands with upper rims extended by aromatic groups have been prepared and their X‐ray structures were analyzed. The reversible encapsulation of a series of n ‐alkylammonium guests was studied by NMR spectroscopy and mass spectrometry. These guests showed different binding modes and unique interactions with the hydrophobic cavity. The trimethylammonium guests bearing n ‐butyl to n ‐hexyl substituents stabilize the C 4 v conformation of the cavitand by additional CH ··· π interactions with the aromatic upper part. The longest n ‐hexylammonium salt adopts a minimal gauche conformation to fit in the cavity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)