Planar and sandwich-type Pr(III) and Nd(III) chlorinated phthalocyaninates: Synthesis, thermal stability and optical properties

A direct synthetic approach to four single-decker and one double-decker novel Pr(III) and Nd(III) complexes with 2,3,9,10,16,17,23,24-octachlorophthalocyaninate and 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexadecachlorophthalocyaninate has been developed. Synthesis of hexadeca-Cl-substituted Nd(III) bisphthalocyaninate has been carried out utilizing two preformed synthetic blocks: Nd(III) octachlorophthalocyaninate acetate and octachlorophthalocyanine ligand. Due to the electron withdrawing effect of 16 chlorine groups, this Nd(III) bisphthalocyaninate was obtained as a redox stable anionic form. Upfield lanthanide-induced shifts of the aromatic proton signals (up to 2.04 ppm for Pr(III) octachlorophthalocyaninate acetate) were observed in the 1H NMR spectra of the obtained phthalocyaninates. Thermal stability of the lanthanide (III) complexes was examined using thermogravimetric analysis combined with mass-spectrometry. The double-decker compound was shown to possess an increased thermal stability in comparison with the single-deckers up to ~400 °C. Linear and nonlinear optical properties of the Cl-substituted Nd(III) and Pr(III) phthalocyaninates have been investigated using z-scan technique. The best nonlinear optical response with the highest excited state absorption cross-section (σ1 = 1.1 × 10−15 cm−2) was found for the hexadeca-Cl-substituted Nd(III) monophthalocyaninate. [Display omitted] -Synthesys of new chloro-substituted Nd and Pr phthalocyaninates was carried out.-Neodymium bisphthalocyaninate was obtained in redox stable anionic form.-Double-decker structure possesses high thermal stability up to 400°C.-The best nonlinear optical response was found for chloro-substituted Nd complex.-Upfield lanthanide-induced shifts of aromatic proton signals were observed.