Ab initio calculations on first-row transition metal porphyrins Part 2. Ground state spin multiplicities, calculated ionisation potentials and electron affinities and their relation to catalytic activity

Zwaans, R.; Lenthe, Joop H. van; Boer, D. H. W. den

doi:10.1016/s0166-1280(96)04563-0

Cited by 23 publications

(20 citation statements)

References 35 publications

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“…Liao and Scheiner performed DFT studies of electronic structure and bonding in MPs and MTPPs [59] and in MPs, metalloporphyrazines (MPz), and metallophthalocyanines (MPc) [60] including Ni-species. Electronic structures of series of neutral, cationic, and anionic MPs, including NiP, were studied using restricted Hartree-Fock (RHF) and Singles and Doubles Configuration Interaction (SDCI) methods [61]. In the earlier work [62] neutral and anionic species of the same MPs were studied using the RHF approach.…”

Section: Introductionmentioning

confidence: 99%

Revealing substituent effects on the electronic structure and planarity of Ni-porphyrins

Barbee

Kuznetsov

2012

Computational and Theoretical Chemistry

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Using density functional theory, we have studied the effects on structural and electronic consequences (including HOMO-LUMO energy gaps, vertical ionization potentials (IPv), and vertical electron affinities (EAv)) of the following two factors: (a) meso- and β-substituents acting as inductive donors (CH3), inductive acceptors that are electron-donating through resonance (Br), inductive electron acceptors (CF3), and resonance enabled acceptors (NO2); and (b) complete replacement of pyrrole nitrogens with P-atoms. The principal results of the study are: (1) For the bare Ni-porphyrin, the solvents were found not to affect the HOMO–LUMO gaps but to change the IPv and EAv noticeably. (2) In the series CH3 → Br → CF3 → NO2 the HOMO-LUMO energy gaps, IPv, and EAv increase for both meso- and β-substituents. The ruffling distortion of the porphyrin core is retained, and becomes stronger for the two acceptor groups. In general, effects of meso-substituents on the ruffling distortion of the porphyrin core is more pronounced. (3) Most significantly, complete replacement of pyrrole nitrogens in the NiP with phosphorus atoms produces the species, NiP(P)4, with the structural and electronic features drastically different from the original NiP. This implies that NiP(P)4 can possess interesting and unusual novel properties, including aromaticity and reactivity, leading to its various beneficial potential applications. Furthermore, NiP(P)4 high stability both in the gas phase and different solvents was shown, implying the feasibility of its synthesis.

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Section: Introductionmentioning

confidence: 99%

Revealing substituent effects on the electronic structure and planarity of Ni-porphyrins

Barbee

Kuznetsov

2012

Computational and Theoretical Chemistry

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“…The geometries of the systems were optimized by the DFT method with B3LYP functional using 6–31G * basis set. The spin multiplicity of the systems was set to take into account the NO 2 radical as well as spin multiplicity of metal-porphyrin complexes [ 40 ]. The interaction energies were calculated by the DFT method with B3LYP functional using 6–31G * basis set.…”

Section: Methodsmentioning

confidence: 99%

Metallic Effects on p-Hydroxyphenyl Porphyrin Thin-Film-Based Planar Optical Waveguide Gas Sensor: Experimental and Computational Studies

et al. 2022

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Metal effects on the gas sensing behavior of metal complexes of 5, 10, 15, 20-tetrakis(4-hydroxyphenyl) porphyrin (THPP) thin film was investigated in terms of detecting NO2 gas by the planar optical waveguide. For this purpose, several THPP and metal complexes were synthesized with different central metal ions: Co(II), Ni(II), Cu(II), and Zn(II). Planar optical gas sensors were fabricated with the metalloporphyrins deposited on K+ ion-exchanged soda-lime glass substrate with the spin coating method serving as host matrices for gas interaction. All of the THPP complex’s films were fully characterized by UV-Vis, IR and XPS spectroscopy, and the laser light source wavelength was selected at 520 and 670 nm. The results of the planar optical waveguide sensor show that the Zn–THPP complex exhibits the strongest response with the lowest detectable gas concentration of NO2 gas for both 520 nm and 670 nm. The Ni–THPP and Co–THPP complexes display good efficiency in the detection of NO2, while, on the other hand, Cu–THPP shows a very low interaction with NO2 gas, with only 50 ppm and 200 ppm detectable gas concentration for 520 nm and 670 nm, respectively. In addition, molecular dynamic simulations and quantum mechanical calculations were performed, proving to be coherent with the experimental results.

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“…All the geometrical optimizations were carried out using the RHF/STO-3G basis set, 8,9 which can be applied to large molecules such as porphyrins in order to decrease calculation time and cost. [10][11][12][13] All internal coordinates were optimized by means of the Berny algorithm. Calculations of the UV-Vis spectra of all optimized structures were performed using the Zerner's intermediate neglect of differential overlap (ZINDO) method [14][15][16][17][18][19][20][21] in the Gaussian 03 program, which can be applied to large molecules to calculate their excited states.…”

Section: Methodsmentioning

confidence: 99%

Ultraviolet—Visible Spectral Analysis for the Reaction of Hydrogen Peroxide with a Titanium(IV)-Porphyrin Reagent

Takamura

Matsumoto

2009

Appl Spectrosc

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A Ti-TPyP reagent, i.e., an acidic aqueous solution of oxo[5,10,15,20-tetra(4-pyridyl)porphyrinato]titanium(IV) complex, TiO(tpyp), was developed as a highly sensitive and selective spectrophotometric reagent for the determination of traces of hydrogen peroxide. The reagent exhibited a single absorption peak at 432 nm, and the addition of hydrogen peroxide to the reagent gave rise to a new peak at 450 nm, with height being proportional to the added hydrogen peroxide concentration. Recently we succeeded in clarifying the reaction specificity of the TiO(tpyp) complex to hydrogen peroxide from the viewpoint of the reaction mechanisms and molecular orbitals based on ab initio calculations. In the present study, we performed ultraviolet-visible (UV-Vis) spectral simulations for individual species in the proposed reaction mechanisms based on the theoretical calculations carried out using the Zerner's intermediate neglect of differential overlap (ZINDO) method, since the assignment of the observed absorption peaks to the respective reaction species is important to confirm the reliability of the analysis of hydrogen peroxide using the Ti-TPyP reagent. The absorption peaks at 432 nm and 450 nm were assigned to a H(2)O-adduct structure of the protonated TiO(tpyp) complex and the important structure corresponding to the monoperoxo TiO(tpyp) complex, respectively, under acidic conditions. Particularly, it should be noted that the addition of water molecules to the protonated TiO(tpyp) complex affects the maximum absorption wavelength appreciably. Taking the addition of water molecules to the complex into consideration, the reaction mechanism proposed previously was revised in this study. The results should contribute to providing a new way to evaluate analytical reagents.

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Ab initio calculations on first-row transition metal porphyrins Part 2. Ground state spin multiplicities, calculated ionisation potentials and electron affinities and their relation to catalytic activity

Cited by 23 publications

References 35 publications

Revealing substituent effects on the electronic structure and planarity of Ni-porphyrins

Revealing substituent effects on the electronic structure and planarity of Ni-porphyrins

Metallic Effects on p-Hydroxyphenyl Porphyrin Thin-Film-Based Planar Optical Waveguide Gas Sensor: Experimental and Computational Studies

Ultraviolet—Visible Spectral Analysis for the Reaction of Hydrogen Peroxide with a Titanium(IV)-Porphyrin Reagent

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