Synthesis, characterization and nonlinear absorption of novel octakis-POSS substituted metallophthalocyanines and strong optical limiting property of CuPc

Abstract

In this study, the preparation of some novel metallophthalocyanine (MPcs) complexes substituted with octakis(mercaptopropylisobutyl-POSS) functional group was achieved. By the reaction of [1-(3-mercapto)propyl-3,5,7,9,11,13,15-isobutylpentacyclo[9.5.1.1^3,9.1^5,15.1^7,13]octasiloxane 1 with 4,5-dichloro-1,2-dicyanobenzene 2 in THF as the solvent in the presence of K₂CO₃ as the base, the phthalonitrile derivative 3 was synthesized. Compound 3 reacted with CoCl₂·6H₂O in ethylene glycol to furnish a novel cobalt(II) phthalocyanine 4. The tetramerization of 3 with urea and CuCl in the absence of solvent gave the novel Cu(II) phthalocyanine 5; while with Zn(OAc)₂·2H₂O in dry DMF gave the novel zinc(II) phthalocyanine 6. The structures of the target compounds were confirmed by elemental analysis, UV/VIS, IR, MALDI-TOF MS and ¹H NMR spectra. Nonlinear absorptions of MPcs 4–6 in chloroform solution were investigated by using Z-scan measurement technique with 4 ns pulses at 532 nm wavelength. While CuPc 5 showed very high nonlinear absorption, MPcs 4 and 6 did not show considerable nonlinear absorption. Investigations of optical limiting properties of 5 revealed that this material is a very good candidate for optical limiting applications.