Iodine(III)-promoted regioselective and efficient synthesis of β-triazolyl BODIPYs for the selective recognition of nickel ions and bovine serum albumin

Dalton Trans. 2022 May 31;51(21):8169-8176. doi: 10.1039/d2dt00946c.

Abstract

Various β-triazolyl tethered BODIPYs were efficiently prepared in a sequential one-pot protocol involving the initial reaction of BODIPY with iodobenzene diacetate (IBD) and sodium azide to in situ generate BODIPY azides followed by a copper-catalyzed azide-alkyne cycloaddition reaction. Under the optimized reaction conditions, various β-triazolyl BODIPYs 5a-i were successfully prepared in good yields and adequately characterized by using UV, NMR, mass spectral data and XRD analyses. The UV-Visible spectra of the prepared β-triazolyl BODIPYs 5a-i showed intense absorption bands (514-545 nm) with a 13-44 nm red shift when compared with those of the parent BODIPY. The selective recognition of compound 5d towards Ni2+ ions (detection limit 0.26 nM) led to significant quenching in the fluorescence intensity over other selected bivalent metal ions. The complex formed between 5d and Ni2+ in a stoichiometry of 2 : 1 was found to have a binding constant of 7.5 × 105 M-1. The fluorescence of compound 5i gets enhanced gradually upon interaction with bovine serum albumin due to its selective and high binding affinity (1.25 × 105 M-1) with protein and a concomitant decrease in the total non-radiative decay rate.

MeSH terms

  • Azides / chemistry
  • Boron Compounds
  • Iodides
  • Iodine*
  • Ions
  • Nickel
  • Serum Albumin, Bovine*

Substances

  • 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene
  • Azides
  • Boron Compounds
  • Iodides
  • Ions
  • Serum Albumin, Bovine
  • Nickel
  • Iodine