Publication details
Oxidation of styrene by Mn (II)-pyridine-2,6-dicarboxylate complex: Synthesis, X-ray structure and DFT studies
| Authors | |
|---|---|
| Year of publication | 2025 |
| Type | Article in Periodical |
| Magazine / Source | JOURNAL OF MOLECULAR STRUCTURE |
| MU Faculty or unit | |
| Citation | |
| web | https://www.sciencedirect.com/science/article/pii/S0022286025001292 |
| Doi | https://doi.org/10.1016/j.molstruc.2025.141440 |
| Keywords | Mn (II) complex; Single-crystal; Density functional theory; Styrene; Oxidation |
| Description | A transition metal complex of Mn (II) formulated as [Mn(dipic)(phen)(H2O)].H2O (complex 1) was successfully synthesized, wherein dipic2- refers to pyridine-2,6-dicarboxylate, and phen refers to 1,10-phenanthroline. Complex 1 was characterized by single-crystal X-ray diffraction (SC-XRD), elemental analysis, and Fouriertransform infrared (FT-IR) spectroscopy. The crystallographic analysis of complex 1 was conducted at 120(2) K. The structure of complex 1 revealed a distorted octahedral geometry within a monoclinic crystal system, belonging to space group P21/c. The central Mn (II) ion was found to be coordinated with three oxygen and three nitrogen atoms originating from three unique ligands. The stability of complex 1 was investigated using density functional theory (DFT) computations. Interaction energy, energies of the most important molecular orbitals, molecular electrostatic potential (MEP) maps, aromaticity of the rings, and density of states (DOS) plots were surveyed. Results disclose that the formation of complex 1 is accompanied by a decrease/increase of negative charge/aromaticity of its rings compared to the ligands. Also, the energy gap (Egap) value of complex 1 is smaller than the parallel data for the ligands. Thus, complex 1 better passes electrons from the barrier to the conductive band than the free ligands. In the following, complex 1 was immobilized onto mesoporous SiO2 particles, yielding a recoverable catalyst [Mn(dipic)(phen)(H2O)].H2O/SiO2 (catalyst 1). Catalyst 1 was characterized using an energy-dispersive X-ray spectrometer (EDS), FT-IR spectroscopy, scanning electron micrograph (SEM), transmission electron microscopy (TEM), and powder X-ray diffraction pattern (PXRD (. Complex 1, and catalyst 1 catalyze the oxidation of styrene in a homogeneous and heterogeneous catalytic system consisting of H2O2. The results of oxidation reactions showed that catalyst 1 is a more effective catalyst for styrene oxidation than complex 1 due to the synergistic effects between metal and support. Finally, the reaction conditions were optimized for catalyst 1. |