Transient absorption spectroscopy porphyrins and photocatalysts

Nanosecond transient measurements were performed with a custom laser spectrometer comprised of a Brillian Quantel laser with frequency doubled (532 nm, 330 mJ) or tripled (355 nm, 160 mJ) option, an Applied Photophysics xenon light source including a mod. 720 150 W lamp housing, a mod. 620 power controlled lamp supply and a mod. 03- 102 arc lamp pulser. Laser excitation was provided at 90° with respect to the white light probe beam. Light transmitted by the sample was focused onto the entrance slit of a SpectraKinetic monochromator (Applied photophysics). Kinetic traces were processed by means of a Agilent digital oscilloscope. A typical pulse energy of 2 mJ cm−2 was used. Zn and Sn refer to the metal centre me = Ph-CO2Me subsituent OH = Ph-CO2H N = pyridyl PH and POEt = Ph-PO(OEt)2 TEOA = 5% v/v triethanolamine added to 1:1 MeCN:H2O solution cat = 10 equiv CoNMeim added N+ = methyl pyridinium structures are provided in the JPEG file.