C-Silylated Calix[4]Arene as a New Receptor for Aspartate in Polar Solvents

Table 1

Association constants between various receptors and NZDA 8 and aspartic acid 9.

Entry	Receptor	Guest	𝐾𝑎 (M^−1)^4	Stoich.
1	4	NZDA 8	1000 (±4%)	1 : 1
2	6	NZDA 8	5000 (±6%)	1 : 1
3	7	NZDA 8	6000 (±10%)	1 : 1
4	10	NZDA 8	2000 (±6%)	1 : 1
5	11	NZDA 8	20000 (±10 %)	2 : 1
6	4	Aspartic acid 9	700 (±7%)	1 : 1
7	6	Aspartic acid 9	3000 (±8%)	1 : 1
8	7	Aspartic acid 9	900 (±11%)	1 : 1
9	10	Aspartic acid 9	300 (±8%)	1 : 1
10	11	Aspartic acid 9	5000 (±4%)	1 : 1