SYNTHESIS, LANGMUIR-BLODGETT-FILM, AND 2ND-ORDER NONLINEAR-OPTICAL PROPERTY OF A NOVEL ASYMMETRICALLY SUBSTITUTED METAL-FREE PHTHALOCYANINE

A novel asymmetrically substituted, soluble, metal-free phthalocyanine with only one reactive nucleophilic substituent of amine was synthesi zed fur the first time by reduction reaction with sodium sulfide nonah ydrate of the nitro group in nitrotri(tert-butylphthalocyanine, which was prepared by mixed condensation of two corresponding diiminoisoindo lines. The compound can be separated by common column chromatography e ither on neutral Al2O3 using chloroform/hexane as the eluting solvent or on silica gel using chloroform as the eluent. The structure was con firmed by elemental analysis, H-1 NMR, UV-vis, IR, and mass spectrosco py. Thermostability of the compound was checked by thermogravimetry an alysis. Langmuir-Blodgett films of the compound were fabricated, and t he configuration of the phthalocyanine molecules at the air-water inte rface was suggested in terms of the limiting area per molecule. Second -harmonic generation (SHG) from monolayer and multilayers was measured , The SH intensities of the monolayer relative to a Y-cut quartz wedge I-2 omega(p-p) and I-2 omega(s-p) are 1.97 x 10(-6) and 1.71 x 10(-7) , respectively. The second-order susceptibility (chi((2))) and the mol ecular hyperpolarizability (beta) values of the monolayer are 3.33 x 1 0(-8) and 5.90 x 10(-30) esu, respectively.