Table 1.

Binding affinities of QAAC4A12C, QAAC4A, and related guest molecules

Guests	Ka/M−1	Ka/M−1
	QAAC4A12C	QAAC4A
Fluorescein	2.1 × 108*	6.3 × 105*
Boron cluster	5.3 × 108*	3.1 × 106*
TCPP	(4.0 ± 0.5) × 1011†	(5.6 ± 1.3) × 107†, ¶
	(3.0 ± 0.7) × 1011‡
TCPPZn	(3.9 ± 0.5) × 1010†	(5.6 ± 1.3) × 107†¶
	(3.1 ± 1.3) × 1010‡
TPPS	(4.4 ± 1.0) × 1011†	(4.6 ± 1.1) × 107†,¶
	(2.8 ± 1.0) × 1011‡
TCPPFe	(4.2 ± 0.2) × 1012§	–#
Camptothecin	1.9 × 108*
Hydrocortisone	1.7 × 109*	2.1 × 105*
Resiquimod	1.7 × 108*	7.3 × 105*
Indocyanine green	1.6 × 108*	2.0 × 107*
Pemetrexed	1.5 × 109*	2.5 × 106*

The 1:1 binding constants of QAAC4A12C and QAAC4A toward different guests were measured in HEPES buffer (10 mM, pH = 7.4, 25 °C).

^*Data from ref. 40.

^†Measured by competitive fluorescence titration using Fl as the indicator.

^‡Measured by competitive fluorescence titration with Na₂B₁₂H₁₂ as the indicator.

^§Measured by competitive UV-Vis titration using Na₂B₁₂H₁₂ as the competitor.

^¶2:1 Host: guest complex.

^#Not measured.