Self-assembled organic nanostructures and nonlinear optical properties of heteroleptic corrole–phthalocyanine europium triple-decker complexes

•Nanostructures of two mixed sandwich complexes were first prepared.•One is belt-like and the other is sheet-like.•Both complexes exhibit good third-order NLO properties.

Two heteroleptic corrole–phthalocyanine europium triple-decker complexes were fabricated into organic nanostructures by the standard phase-transfer method. The investigated compounds are represented by Eu2(Pc)2[Cor(ClPh)3] (1) and Eu2[Pc(OC8H17)8]2[Cor(ClPh)3] (2), where Pc represents the dianion of phthalocyanine and Cor(ClPh)3 the trianion of 5,10,15-tri(4-chlorophenyl)corrole. Both compounds 1 and 2 show typical electronic absorption spectra for a non-aggregated molecular structure in chloroform or toluene. However, in methanol compound 1 self-assembled into belt-like nanostructures while compound 2, which possesses long OC8H17 alkoxy side chains, self-assembled into large scale sheet-like nanostructures. The third-order nonlinear optical properties of both triple-decker compounds were also investigated in toluene by the Z-scan technique and characterized as showing nonlinear reverse saturation absorption and self-defocusing behavior. A third-order nonlinear optical susceptibility, χ(3), of 3.18 × 10−10 and 3.35 × 10−10 esu was obtained for 1 and 2, respectively, thus indicating the potential application of these compounds in the field of optical devices.

Graphical abstractNanostructures of two heteroleptic corrole–phthalocyanine europium triple-decker complexes with different phthalocyanine substituents were prepared and characterized. The examined compounds self-assembled into two different nanostructures; one is belt-like and the other is sheet-like. The third-order nonlinear optical properties of both triple-decker compounds were investigated in toluene by the Z-scan technique and characterized as showing nonlinear reverse saturation absorption and self-defocusing behavior. The third-order nonlinear optical susceptibility values indicate that the examined compounds have potential applications in the fields of organic semiconductors and optical limiting devices.Figure optionsDownload full-size imageDownload as PowerPoint slide