Synthesis and third-order NLO properties in LB films of triazolehemiporphyrazines

Langmuir-Blodgett (LB) films of free and cobalt(II)-metallated triazolehemiporphyrazines (2–4), including some new synthesized compounds (3–4), have been prepared and characterized. All investigated molecules adopt an edge-on arrangement in the film as previously found for the structurally related phthalocyanines (Pcs). The real and imaginary parts of the third-harmonic susceptibility χ(3) (3ω:ω,ω,ω) have been measured at 1.06 μm fundamental wavelength. Values are similar to those obtained for LB films of Pcs. No significant effects associated with cobalt metallation have been found at variance with previous results in solution at λ = 1.3 and λ = 1.9 μm.