Theoretical and experimental investigations of complexation with BF₃.Et₂O effects on electronic structures, energies and photophysical properties of Anil and tetraphenyl (hydroxyl) imidazol

Abstract

The novel compounds (E)-2-(((4-hydroxyphenyl)imino)methyl)phenol, Tetraphenyl (hydroxyl) imidazole and their corresponding Boron difluoride complexes were synthesized and characterized by spectroscopic techniques.Density functional theory calculations at B3LYP-D3/6-311++G (d, p) level of theory were performed for the geometric parameters. The MEP surface studies were used to understand the behavior of molecules in terms of charge transfer and to determine how these molecules interact. We used the GIAO and the B3LYP-D3 with a 6-311++ G (d, p) basis set to simulate the ( 1 H-NMR and 19 F-NMR) and the IR spectra, respectively. The corresponding calculated results are in good agreement with the experimental data. The stability of the molecule arising from hyperconjugation interaction and charge delocalization were analyzed using NBO analysis. FMOs revealed the occurrence of charge transfer within the molecule. The complexation using BF 3 .Et 2 O was also found to have remarkable effects on the electrochemical properties of the studied molecules, where (b) and (d) present lower chemical stability, higher reactivity and higher polarizability than (a) and (c), respectively. Moreover, the energy gap of (a) and (c) decreased after complexation using BF 3 .Et 2 O, indicating the reliability of the electrochemical evaluation of LUMO and HOMO energy levels. These values are the factors explaining the possible charge transfer interaction within the molecule. The absorption and emission spectra of the model compound were also simulated and compared to experimental observations in the DMF solvent. The results of DFT calculations supported the structural and spectroscopic data and confirmed the structure modification of frontier molecular orbitals for BF 2 complexes as well as tunable potentials and energy levels.

A combined experimental and theoretical study on the synthesis, spectroscopic characterization of Magnesium(II) porphyrin complex with DMAP axial ligand and antifungal activity

“…Furthermore, the chemical shift values of the N(CH 3 ) 2 protons (Ha,), the ortho (H L,o ) and the meta (H L,m ) protons of the DMAP axial ligand of (I) are 7.67, 7.25 and 2.70 pm, respectively. We notice a small diminishing of the resolution of the spectra which is probably caused by the ultrafast ripping process in solution[51].…”

A BF2 Chelate Exhibiting Excimer‐like Fluorescence with an Unusually Large Stokes Shift in the Crystalline Phase

“…These include examples of the well‐known boron dipyrromethene (BODIPY) dyes [15] and certain derivatives of the corresponding BOPHY family [16] . Furthermore, several boranil complexes exhibit bright fluorescence in the solid state, [17] despite being only weakly emissive when dissolved in polar solvents [18] . The latter class of boron(III) chelates are attractive in terms of their facile synthesis, which allows large scale isolation of diverse derivatives.…”

“…[16] Furthermore, several boranil complexes exhibit bright fluorescence in the solid state, [17] despite being only weakly emissive when dissolved in polar solvents. [18] The latter class of boron(III) chelates are attractive in terms of their facile synthesis, which allows large scale isolation of diverse derivatives. These boranils, together with several related structures, [19] favour intramolecular charge-transfer interactions along the molecular axis and this helps to increase the Stokes shift.…”