Table 2.

Thermodynamic parameters during the complexation

Host–guest pair	Ka M−1	ΔG* kcal/mol	ΔH† kcal/mol	−TΔS kcal/mol
QAAC4A12C-Fl	2.1 × 108	−11.2	−(6.1 ± 0.5)	−5.1
QAAC4A-Fl	6.3 × 105	−7.8	−(6.7 ± 1.1)	−1.1
QAAC4A12C-Na2B12H12	5.0 × 108	−11.8	−(7.4 ± 0.8)	−4.4
QAAC4A-Na2B12H12	3.1 × 106	−8.8	−(6.6 ± 0.9)	−2.2
QAAC4A12C-TPPS	4.4 × 1011	−15.8	−(15.6 ± 0.4)	−0.2
QAAC4A-TPPS	4.6 × 107	−10.4	−(16.5 ± 1.1)	6.1

^*The ΔG was calculated by K_a obtained from fluorescence titration.

^†The ΔH was measured by ITC in HEPES buffer (10 mM, pH = 7.4, 25 °C), and the −TΔS was calculated by ΔG − ΔH.