Table 3. NPA Partial Charges (q, e) and Nucleophilic Parr Function Values (P_k^–) Calculated at the M06-2X/aug-cc-pVTZ Level of Theory for the [ECX]⁻ Anions and MeC≡P.

	q			Pk–
dienophile	E	C	X	E	C	X
[PCO]−	–0.45	0.14	–0.69	0.81	–0.04	0.23
[PCS]−	–0.01	–0.73	–0.26	0.69	–0.22	0.53
[PCSe]−	0.08	–0.83	–0.25	0.54	–0.32	0.77
[AsCO]−	–0.49	0.17	–0.68	0.82	0.00	0.18
[AsCS]−	–0.04	–0.75	–0.21	0.73	–0.15	0.42
[AsCSe]−	0.06	–0.87	–0.20	0.66	–0.32	0.65
P≡CMe	0.52	–0.53		0.69	0.20