title: Bis-8-hydroxyquinoline-armed diazatrithia-15-crown-5 and diazatrithia-16-crown-5 ligands: possible fluorophoric metal ion sensors.
abstract: The synthesis and preliminary photophysical properties of a series of diazatrithia-15-crown-5 and diazatrithia-16-crown-5 ligands containing two 8-hydroxyquinoline sidearms are reported. The ligands were prepared by a two-step process. First, diazatrithiacrown ethers 11 and 12 were prepared by treating bis(alpha-chloroamide) 5 with various dimercaptans followed by reduction using a boron-THF complex. Hydroxymethyl-substituted macrocycle 12 was rearranged to hydroxy-substituted diazatrithia-16-crown-5 in refluxing aqueous HCl. Macrocyclic diamines 11-13 were converted to either 5-chloro-8-hydroxyquinolin-7-ylmethyl-substituted diazatrithiacrown ethers 14-16 by a Mannich aminomethylation reaction or to 8-hydroxyquinolin-2-ylmethyl-substituted diazatrithiacrown ethers 17-19 by reductive amination using 8-hydroxyquinoline-2-carboxaldehyde. Preliminary photophysical studies show that ligands 16 and 19 exhibit increased fluorescence in the presence of Zn(2+), indicating that these ligands could be chemical sensors for Zn(2+).
authors.affiliation: Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, USA.
authors.forename: R T
authors.initials: RT
authors.lastname: Bronson
authors.forename: J S
authors.initials: JS
authors.lastname: Bradshaw
authors.forename: P B
authors.initials: PB
authors.lastname: Savage
authors.forename: S
authors.initials: S
authors.lastname: Fuangswasdi
authors.forename: S C
authors.initials: SC
authors.lastname: Lee
authors.forename: K E
authors.initials: KE
authors.lastname: Krakowiak
authors.forename: R M
authors.initials: RM
authors.lastname: Izatt