Abstract
The conformations of tetracationic paracyclophane and metacyclophane derivatives containing quaternary salts of para-2,2-diazaterphenyl were investigated. The molecules were synthesized as the bromide and hexafluorophosphate salts which allowed solubility in aqueous and organic solvents. Molecular mechanics led to the notion that these cyclophanes would populate collapsed and open conformations in water and only populate open conformers in organic solvent. VT NMR studies indicated that the open and the collapsed conformers did not exchange on the NMR timescale. Large, positively charged clefts in one of these conformers bound flat anions between pyridinium rings as would molecular-scale tweezers.
Original language | English |
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Pages (from-to) | 2991-2996 |
Number of pages | 6 |
Journal | Tetrahedron |
Volume | 57 |
Issue number | 15 |
DOIs | |
State | Published - Apr 9 2001 |
Bibliographical note
Funding Information:NSF CHE-9702287 supported this work. The 400 MHz NMR instruments used in this research were upgraded with funds from the CRIF program of the National Science Foundation (CHE 997841) and from the Research Challenge Trust Fund of the University of Kentucky. AC-G thanks R. L. Cerny, Ph.D. at the Nebraska Center for ESI and FAB MS analysis of 2 ·4Br.
Funding
NSF CHE-9702287 supported this work. The 400 MHz NMR instruments used in this research were upgraded with funds from the CRIF program of the National Science Foundation (CHE 997841) and from the Research Challenge Trust Fund of the University of Kentucky. AC-G thanks R. L. Cerny, Ph.D. at the Nebraska Center for ESI and FAB MS analysis of 2 ·4Br.
Funders | Funder number |
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National Science Foundation (NSF) | CHE-9702287, CHE 997841 |
University of Kentucky |
Keywords
- Anion binding
- Conformation
- Cyclophane
- Dynamic NMR
- GB/SA
- Molecular mechanics
- Molecular recognition
- Molecular tweezers
- Solvation
- π-stacking
ASJC Scopus subject areas
- Biochemistry
- Drug Discovery
- Organic Chemistry