Table 1. The distances to the transitions state, χ_β, kinetic off-rates, k_off, and the average bond lifetime, τ_off = 1/k_off.

No. of bonds	χβ, Å	Koff, s-1	τoff
1	2.8 ± 0.2	2.6 × 10-3	284 s
2	2.0 ± 0.4	7.2 × 10-5	3.8 h
3	2.4 ± 1.5	3.6 × 10-8	320 days

Values were determined from the fits of the data in Fig. 4 to Eq. 1.