FT visible absorption spectroscopy of porphine in noble gas matrices

Polarized visible absorption spectra of free-base porphine photo-oriented in noble gas matrices were observed by Fourier-transform spectroscopy. The symmetries of over 60 vibronic transitions in the Q_x region and about 20 in the Q_y region were assigned and the symmetric N---H stretching vibration in the Q_x state was identified (3386 and 3392 cm⁻¹ in the two sites in xenon matrix).