Unique "cradled barbell" complex between a secondary diammonium ion and bis(m-phenylene)-32-crown-10

Authors
Bryant, WS Guzei, IA Rheingold, AL Gibson, HW
Citation
Ws. Bryant et al., Unique "cradled barbell" complex between a secondary diammonium ion and bis(m-phenylene)-32-crown-10, ORG LETT, 1(1), 1999, pp. 47-50
Citations number
25
Categorie Soggetti
Organic Chemistry/Polymer Science
Journal title
ORGANIC LETTERS
ISSN journal
15237060 → ACNP
Volume
1
Issue
1
Year of publication
1999
Pages
47 - 50
Database
ISI
SICI code
1523-7060(19990715)1:1<47:U"BCBA>2.0.ZU;2-A
Abstract
The complexation between N,N'-dibenzyl(m-xylylene)diammonium bis(hexafluoro phosphate) (2) and bis(m-phenylene)-32 crown-10 (5) was shown to occur in s olution by nuclear magnetic resonance with 1:1 stoichiometry and a K-a valu e of 189 +/- 19 M-1. A crystal structure of 2:5 revealed a unique 1:1 "exo" or "cradled barbell" complex, instead of the expected pseudorotaxane. This unexpected result illustrates that caution be used in interpreting the res ults from these types of complexes in the solution and "gas" phases on the basis of crystal structures.