Table 2. Protonation constants of synthesized chelators TE-8, TE-8, TE-9, TE-10, and TE-11. Titrations were performed in the presence of 0.1 M KCl. Ligands were prepared in DMSO and diluted to micromolar concentrations, with final DMSO content below 2% (v/v).

	log KHL	log KH2L	log KH3L	log KH4L
TE-1a	9.84(3)	5.36(4)	3.56(5)
TE-4a	9.25(3)	5.99(4)	3.09(7)	2.84(6)
TE-7	10.56(6)	7.99(6)	5.27(6)	1.83(7)
TE-8	11.54(3)	8.52(3)	6.43(3)	2.75(4)
TE-9	10.06(1)	7.23(5)	5.47(5)	3.29(2)
TE-10	8.72(1)	5.59(3)	5.20(7)	2.85(3)
TE-11	10.25(7)	7.85(7)	4.43(9)	4.01(8)
BPPAb	8.65(1)	6.26(1)	2.92(1)
1,4-Et4DO2Ac	11.5(1)	11.1(3)	4.4(2)	3.6(2)

^aPreviously reported pyridinophane-based ligands using potentiometric titrations in 0.16 M NaCl.⁴³

^bPyridinophane-based ligand reported by Toàn et al.,⁶³ using potentiometric titrations in 0.16 M NaCl.

^cDO2A-type ligands reported by Xu et al.,⁶⁹ using potentiometric titrations in 0.1 M KCl.