*2.2. Instrumentation*

UV-VIS spectra, and some kinetic experiments, were followed on a Beckman DU-640 UV–VIS or on an Agilent HP-6456 diode array spectrophotometer, both equipped with cell carriers thermostated with water from a refrigerated/heating circulator, Julabo F1 2-ED, and were attached to computers for data storage. A product analysis was carried out with the aid of a WATERS HPLC system, equipped with a model 2487 dual-λ absorbance detector, a model 717 automatic injector, a model 600 quaternary pump, and a computer for data storage. The dediazoniation products were separated with a reverse phase column (Microsorb-MV C-18 (Rainin, 25 cm length, 4.6 mm internal diameter, and 5 μm particle size) using an acidic 70/30 (*v*/*v*) MeOH/H2O mobile phase, containing 10−<sup>4</sup> M HCl. The injection volume was set at 25 μL in all runs and the UV detector was set at 220 nm. Details on the method can be found elsewhere [42,45].
