Table 3. Entropy Changes [ΔS_HD^o(XRH^•+)] and Activation Entropies [ΔS_HD(XRH^•+)] of XRH^•+ Releasing H^• (unit: cal mol^–1 K^–1).

XRH	ΔSHDo(XRH•+)a	ΔSHD≠(XRH•+)b	XRH	ΔSHDo(XRH•+)a	ΔSHD≠(XRH•+)b
1RH	27.17	1.48	10RH	23.26	0.07
2RH	24.28	–0.60	11RH	23.10	0.39
3RH	25.26	–0.45	12RH	24.53	3.00
4RH	23.15	0.24	13RH	24.62	2.53
5RH	25.91	0.72	14RH	24.99	1.71
6RH	27.52	4.45	15RH	21.09	–3.79
7RH	24.32	2.99	16RH	25.14	–2.42
8RH	23.69	1.47	17RH	20.56	–3.28
9RH	25.27	1.23

^aΔS_HD^o(XRH^•+) = [ΔH_HD(XRH^•+) – ΔG_HD^o(XRH^•+)]/T.

^bΔS_HD^≠(XRH^•+) = [ΔH_HD(XRH^•+) – ΔG_HD^≠(XRH^•+)]/T.