Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5280495 | Tetrahedron Letters | 2005 | 6 Pages |
The 4-amino-1,8-naphthalimide-based anion receptor 3 binds dihydrogenphosphate with 1:1 stoichiometry through cooperative hydrogen bonding to a naphthalimide N-H and thiourea N-H groups. This was clearly established from 1H NMR titration experiments in DMSO-d6 where a substantial shift in the resonance for the naphthalimide N-H was observed concomitant with the expected thiourea N-H chemical shift migration upon successive additions of H2PO4â. However, whilst 1H NMR titration experiments indicate that 3 was capable of binding other anions such as acetate, the naphthalimide N-H does not participate and the N-H resonance was essentially invariant during the titration. The lack of cooperative binding in this instance was justifiable on steric grounds.
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