DFT and TDDFT study of 4-((furan-2-ylmethyl)sulfonyl)-substituted zinc(II) phthalocyanine: importance of Grimme dispersion with a Becke—Johnson damping correction and the substituent effect

Abstract

In this work, we report a theoretical study on the structural, vibrational, and electronic properties of 4-((furan-2-ylmethyl)sulfonyl)-substituted zinc(II) phthalocyanine. We start to study the performance of DFT functionals for the unsubstituted systems using the B97D3, B3LYP, M06-2X, PBE1PBE, and BMK functionals. The B97D3 functional with a dispersion correction is in good agreement with the theoretical and experimental results, which suggests that the D3 dispersion plays an essential role in the study of different properties of zinc phthalocyanine. Using the B97D3 functional with def2TZVP for Zn and 6-311+G(d,p) for the other atoms, we determine the structural, vibrational, and electronic properties of 4-((furan-2-ylmethyl)sulfonyl)-substituted zinc(II) phthalocyanine. We notice that the HOMO is localized on both substituent and zinc(II) phthalocyanine but the LUMO is the same as in the unsubstituted compound. This demonstrates a higher absorption wavelength in agreement with the experimental results of this substituted system.