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Effect of Hydrogen Binding on Selective Recognition of Halide Anions
Author(s) -
Du Juan,
Kang Kang,
Hu Jinchuan,
Mao Lijun,
Yuan Lihua,
Feng Wen
Publication year - 2016
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.201600237
Subject(s) - chemistry , hydrogen bond , halide , intramolecular force , binding constant , pyridine , chloroform , crystallography , amide , titration , hydrogen halide , inorganic chemistry , molecule , stereochemistry , binding site , medicinal chemistry , organic chemistry , alkyl , biochemistry , halogen
Abstract The interplay of molecular rigidity enforced by interior or exterior hydrogen bonding and affinity for binding halide anions is described to demonstrate the effect of intramolecular hydrogen bonding in anion recognition process. To this end pyridine‐2,6‐dicarboxamides 1 and 2 , and aromatic oligoamides 3 and 4 containing intramolecular hydrogen bonds were explored for their ability in associating with tetrabutylammonium halide (Cl − , Br − , and I − ). Binding constants in chloroform solution were calculated using nonlinear curve‐fitting method based on 1 H NMR titration experiments. The trimeric amide 3 , which adopts a crescent conformation as revealed by single‐crystal X‐ray diffraction analysis, strongly binds chloride anion with binding constant as high as 379 L·mol −1 . This is more than 6 times greater than the binding constant for the control receptor 2 with a backbone that is only partially rigidified. The comparative data provided supportive information for rationalizing the observed affinity difference in binding halide anions in terms of local preorganization effected by interior or exterior hydrogen bonding.