The UV-Visible spectra were recorded using a deuterium tungsten
halogen light source (DT-Mini 2GS, Ocean Optics), a quartz cuvette
and a miniature CCD array spectrophotometer (USB-4000, Ocean
Optics), connected through two optical fibres (600 μm fibre, P600-
025-SR). Using this set-up we were able to obtain a complete scan
(from 250 to 800 nm) in b1 s.