Insights into theoretical detection of CO2, NO, CO, O2, and O3 gases molecules using Zinc phthalocyanine with peripheral mono and tetra quinoleinoxy substituents: Molecular geometries, Electronic properties, and Vibrational analysis

Abstract

In this paper, Zn-phthalocyanine (ZnPc) with peripheral mono (ZnPcR 1 ) and tetra quinoleinoxy (ZnPcR 4 ) substituents of the phtalocyanine ring were theoretically studied for the adsorption of NO, CO 2 , CO, O 2 and O 3 gases using DFT/B3LYP-D3/6–311++ G (d, p) method. Data displayed a strong interaction between ZnPc, ZnPcR 1 and ZnPcR 4 and the studied gases. The calculated adsorption energies were - 19.509, - 13.175, - 7.538, - 5.359, and - 5.280 k c a l ∙ m o l - 1 for ZnPcR 4 /O 3 , ZnPcR 4 /O 2 , ZnPcR 4 /CO 2 , ZnPcR 4 /NO, and ZnPcR 4 /CO, respectively. The absorption spectra of the studied complexes were determined using time-dependent density functional theory (TD-DFT). The blue shifted λ max values confirmed the interaction between the complexes and the gases. The electronic properties, geometries, stabilities, noncovalent interactions reduced density gradient (NCI-RDG) and natural population analysis (NPA) have been carried out. FT-IR spectra of all studied complexes displayed a major change in the vibrational frequency and signal strength after gases adsorption. In brief, the optical spectra, the change in the energy gap and the vibrational spectra showed that the studied gases mainly O 3 and O 2 were very sensitive to ZnPc, ZnPcR 1 , and ZnPcR 4 and hence could be used in sensors.