Comprehensive spectroscopic, electrochemical, X-ray crystal structure and QTAIM/ NCI-RDG analyses computations of a new Bis(η1-Formato) chromium(III) Meso-arylporphyrin complex - theoretical insights into sensing efficiency for CO2, NO2 and O2 gases

Herein, we have presented a new chromium(III) hexacoordinated metalloporphyrin with two η¹-formato axial ligands. Based on the single crystal X-ray molecular structure, the formula of this new coordination compound is [Na(crypt-222)][Cr^III(TMPP)(η¹-OCOH)₂]^•0.3CH₂Cl₂0^•3H₂O (complex I), where TMPP is the (meso-tetra(para-methoxyphenyl)porphyrinate and crypt-222 is the cryptand-222. UV/Vis, fluorescence, infrared, mass spectrometry, and cyclic voltammetry techniques were employed for a complete characterization and the electronic properties study of complex I. A Hirshfeld surface analysis was performed to elucidate the intermolecular interactions responsible for the stability of the crystal lattice of complex I. In order to get further information on the intermolecular interactions and the reactivity of the title compound, DFT/TDDFT calculations were carried out, including molecular structure optimization using the DFT/B3LYP-D3/LanL2DZ level of theory, the frontier molecular orbitals (FMOs) calculations, the molecular electronic potential analysis (MEP), and the QTAIM-NCI-RDG analyses. Furthermore, the sensing efficiency of our new chromium(III) metalloporphyrin for the CO₂, NO₂, and O₂ gas molecules is also reported.