title: Solution and structural binding studies of phosphate with thiophene-based azamacrocycles.
abstract: Two thiophene-based monocyclic receptorsL1andL2have been studied for phosphate binding in solutions (D2O and DMSO-d6) by1H NMR and31P NMR titrations, and in the solid state by single crystal X-ray analysis. Results from1H NMR titrations suggest that the ligands bind phosphate anions in a 1:2 binding mode in DMSO-d6, with the binding constants of 5.25 and 4.20 (in logK), respectively. The binding of phosphate toL1andL2was further supported by31P NMR in D2O at pH = 5.2. The crystal structure of the phosphate complex ofL1reveals unambiguous proof for the formation of a ditopic complexviamultiple hydrogen bonds from NH···O and CH···O interactions.
authors.affiliation: Department of Chemistry and Biochemistry, Jackson State University, Jackson, MS 39217, USA.
authors.forename: Syed A
authors.initials: SA
authors.lastname: Haque
authors.affiliation: Department of Chemistry and Biochemistry, Jackson State University, Jackson, MS 39217, USA.
authors.forename: Rainier S
authors.initials: RS
authors.lastname: Berkley
authors.affiliation: Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA.
authors.forename: Frank R
authors.initials: FR
authors.lastname: Fronczek
authors.affiliation: Department of Chemistry and Biochemistry, Jackson State University, Jackson, MS 39217, USA.
authors.forename: Md Alamgir
authors.initials: MA
authors.lastname: Hossain
keywords: Anion binding; Azamacrocycle; Ditopic complex; Phosphate complex