Table 2. Hydrolysis data for [(η⁶-arene)Ru(en)X][PF₆]_n (n = 1 or 2) complexes at 298 K and cytotoxicity (IC₅₀) toward A2780 human ovarian cancer cells.

Complex	Arene	X	kH2O, 10-3 s-1	[Ru(H2O)]e, %	IC50, μM
18	hmb	dfp	0.0208 ± 0.0001	32.6	ND
2	bip	Cl	1.24 ± 0.13	76.2	5†
6	bip	Br	1.05 ± 0.04	ND	ND
10	bip	I	0.321 ± 0.045	ND	5
15	bip	N3	0.0315 ± 0.0043	4.5	4
3	ind	Cl	2.29 ± 0.14	76.3	8
7	ind	Br	2.16 ± 0.05	ND	ND
11	ind	I	0.512 ± 0.046	ND	ND
4	bz	Cl	1.98 ± 0.02	98.1	17†
8	bz	Br	1.50 ± 0.02	ND	ND
12	bz	I	0.294 ± 0.003	20.5	20†
13	p-cym	I	0.948 ± 0.008	5.0	9†
22	dha	Cl	2.23 ± 0.02	80.4*	2†
23	tha	Cl	2.36 ± 0.02	80.0*	0.5†

Data for other hmb complexes are provided in Fig. 2. [Ru(H₂O)]_e, equilibrium percentage (average of three independent measurements) of aqua complex in 2 mM solution of Cl complex; ND, not determined.

^*In 15 mM NaClO₄ (18).

^†Data are from ref. 11.