DABCO cadmium(II) tetrakis(4-metoxyphenyl)porphyrin complex – Structure, photophysical properties, and adsorpion removal of methylene blue dye

Abstract

In this work, a new cadmium(II) complex namely the (1,4-diazabicyclo[2.2.2]octane)(mesotetrakis(4-tert-methoxyphenyl)porphyrinato)cadmium(II) with the formula [Cd(TMPP)(DABCO)] (I) (DABCO = 1,4-diazabicyclo[2.2.2]octane) was successfully synthetized. The structure of (I) have been characterized by FT-IR, 1 HNMR, UV-visible, fluorescence spectroscopies and single crystal Xray diffraction technique. DFT calculations has been made for the structural, 1 H NMR spectroscopy and IR spectra analysis. The adsorption of methylene blue (MB) dye was studied to examine the efficiently of the [Cd(TMPP)(DABCO)] for removing the cationic dyes from aqueous solution. The Langmuir adsorption capacity (Q 0 max ) at 290 K and pH 7.0 was found to be 69.24 mg.g -1 . The adsorption mechanism which involved π-π interaction between the MB dye molecule and the porphyrin ring of (I) is well described by the pseudo second-order and Elovich models.

113Cd as a Probe in NMR Studies of Allosteric Host‐Guest‐Ligand Complexes of Porphyrin Cage Compounds

“…Here, the cadmium center is displaced 0.790 Å outwards of the porphyrin plane in the direction of the tbupy ligand. The displacements of the cadmium center from the mean porphyrin plane in the crystal structures are in line with those observed for previously reported cadmium porphyrin complexes with axial ligands such as 1,4-diazabicyclo[2.2.2]octane (DABCO) (0.746 Å) [26] and morpholine (0.60 Å). [27] The displacements are not the result of a too-tight fit of the cadmium center, since in the crystal structure of a cadmium porphyrin with two dioxane axial ligands, the cadmium center is located in the porphyrin plane.…”

Synthesis, Characterization, DFT and Photocatalytic Studies of a New Pyrazine Cadmium(II) Tetrakis(4-methoxy-phenyl)-porphyrin Compound

“…On the other hand, according to the UV-Vis absorption spectra (Figure 10) for [Cd (TMPP)(Pyz)] (1), the Soret and Q bands were observed at 440 nm, 579, and 623 nm, respectively. A slight redshift of the Soret and Q bands for complex (1) was observed compared to [Cd(TMPP)], which could be related to the increase in the doming distortion caused by the coordinated pyrazine axial ligand [21]. Notably, the important redshift of the absorption bands due to the decrease in the HOMO-LUMO energy was related to the deformation of the porphyrin core [31].…”

“…[Cd(TMPP)], and 0.03 for [Cd(TMPP)(Pyz)]. The (Φf) of ( 1) was higher than that of [Cd(TMPP)(DABCO)] (Φf = 0.01) [21] and lower than that of [Cd(TClPP)(morph)] [36] (Table S4). The fluorescence lifetime also decreased from 7.8 ns for H2TMPP to 1.6 ns for complex (1).…”

“…Additionally, the pyrazine axial ligand encourage intersystem crossing to the triplet state [34,35], resulting in reduced e quantum yields (Φf), which diminished from 0.084 for H 2 TMPP to 0.06 for [Cd(TMPP)], and 0.03 for [Cd(TMPP)(Pyz)]. The (Φf) of (1) was higher than that of [Cd(TMPP)(DABCO)] (Φf = 0.01) [21] and lower than that of [Cd(TClPP)(morph)] [36] (Table S4). The fluorescence lifetime also decreased from 7.8 ns for H 2 TMPP to 1.6 ns for complex (1).…”