Binding constants (K, M⁻¹)^a,b between cages 1–2 and selected cations in dichloromethane.

	Na+		Cs+
	K 11	K 12	K 11	K 12
1a	6 × 108	3 × 106	1 × 107	—
1b	4 × 109	2 × 106	2 × 108	—
2a	1 × 1011	2 × 108	4 × 109	3.3 × 106
2b	9 × 1012	1 × 109	2 × 107	c

^aEstimated errors: ±15%.

^bHost : guest stoichiometry is (1 : 1) or (1 : 2).

^c<3 × 10⁶.