Table 3.

Halide anion association constants for the 3⋅ChB^R receptor systems.

	Anion association constants K a [M−1] for 3⋅ChBR series[a]
Anion[b]	pOMe	pMe	Ph [c]	pF	pCl	mF	mCF3	pCF3	2F [c]	3F [c]	2CF3	ρ [g]	r [h]
Cl−	450	1140	1360	1610	4790	14 000[f]	>105[d]	>105[d]	>105[d]	>105[d]	>105[d]	2.20±0.29	0.97
Br−	230	518	822	863	2540	2740	7540	7270	5180	11 800[f]	19 900[f]	1.59±0.13	0.97
I−	NB[e]	NB[e]	119	398	674	592	1450	1620	1040	1750	3980	1.28±0.23	0.90

[a] Association constants determined by Bindfit analysis of Te‐aryl chemical shift perturbations unless otherwise specified, errors ≤10 % unless otherwise specified, conducted in [D₆]acetone. [b] Anions added as their tetrabutylammonium salts. [c] Determined by monitoring of internal pyridine proton signal. [d] Too large to be accurately quantified by¹H NMR titration. [e] No binding. [f] Error ≤26 %. [g] ρ refers to the value from the Hammett equation [h] Pearson's correlation coefficient.