fs transient spectroscopy of TBA-KMoSn[BOD] in MeCN
2020-04-20T09:07:59Z (GMT) by
Transient absorption spectroscopy was performed on acetonitrile solution samples of the bodipy hybrid TBA-KMoSn[BOD] with an OD 0.25 to 0.9 AU, in a 1 mm pathlength quartz cuvette. The samples were purged with N2 before each measurement. The transient absorption setup was based on an amplified Ti:sapphire laser (Mai-Tai, Spitfire; both Spectra Physics) providing 80 fs pulses at 800 nm at the rate of 1 kHz. The pulses were split into two beams: excitation pulses (525 nm) were generated by optical parametric amplifier OPA (TOPAS C), Light Conversion) and probe pulses (white light supercontinuum) were generated by a CaF2 crystal. The excitation and delayed probe beams were set to overlap in the sample (1 mm quartz cuvette). Consequently, the probe beam was dispersed on a photodiode array coupled to a spectrograph (Pascher Instruments). The transient absorption signal was calculated from a difference between spectra of two consecutive probe pulses passing though excited and unexcited sample, respectively. This was maintained by an optical chopper running at a frequency of 500 Hz which was synchronized with the laser. The angle between polarizations of excitation and probe beam were set to the so-called magic angle (54.7 degrees) to avoid observation of dynamics connected to transition dipole rotation. The excitation intensity used was 650 μW, corresponding to 1.3 nJ per pulse.
The filenames refer to the sample and addition of aliquots of trifluoroacetic acid (numbers refer to molar equivalents of acid).