Third-order nonlinear optical properties of sandwich-type mixed (phthalocyaninato)(porphyrinato) europium double- and triple-decker complexes

The nonlinear optical (NLO) properties of sandwich-type mixed tetrapyrrole europium double- and triple-decker complexes Eu(Pc)(TPYRP) (1) and Eu2(Pc)2(TPYRP) (2) [Pc = unsubstituted phthalocyaninate, TPYRP = 5,10,15,20-tetrakis(1-pyrenyl)porphyrinate] were investigated by Z-scan experiments in CHCl3 solution at 1064 nm wavelength, showing enhanced third-order NLO properties compared with metal free phthalocyanine, porphyrin, and pyrene. Strong intramolecular π–π interaction and two-photon resonance are considered responsible for the large optical nonlinearity. The third-order NLO response of double-decker 1 is larger than that of triple-decker 2 probably associated with the unpaired electron in the former double-decker compound.

► Both sandwich-type complexes showed large third-order nonlinearity.
► Third-order NLO properties of them were studied using Z-scan method.
► The near IR absorption band of Eu(Pc)(TPYRP) improves the third-order NLO property.