Photophysical properties and optical limiting property of a soluble chloroaluminum-phthalocyanine

A chloroaluminum-phthalocyanine (AlCl-Pc) with tetra-alpha-butoxy chains (AlCl-Pc-OC4) has been synthesized and the photophysical parameters have been determined using steady-state and time-resolved absorption as well as emission spectroscopy. A luminescence from S-2 excited state with long lifetime (5.71 ns) is observed. A multi level model has been proposed to explain the photophysical processes after Soret-band excitation (lambda(ex) = 355nm). The optical limiting performance for 532nm-7ns laser pulses of AlCl-Pc-OC4 has been investigated in THF solution. The sigma(ex) and ratio of sigma(ex)/sigma(0) has been calculated. The good optical limiting performance is attributed to a reverse saturable absorption mechanism. It indicates that AlCl-Pc-OC4 could be promising candidates for optical limiting material. (C) 2005 Optical Society of America.