A DFT/TDDFT interpretation of the ground and excited states of porphyrin and porphyrazine complexes

Baerends, Evert Jan; Ricciardi, Giampaolo; Rosa, Angela; Gisbergen, S.J.A. van

doi:10.1016/s0010-8545(02)00093-0

Cited by 301 publications

(252 citation statements)

References 65 publications

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“…Experimental and theoretical studies on porphyrins focussed on the origin and the intensities of the lowest ligand to ligand absorption bands, the Q and the B bands, which are successfully explained by Gouterman's fourorbital model [2] and more recently reconsidered within the TD-DFT method [3,4].…”

Section: Introductionmentioning

confidence: 99%

A DFT based ligand field study of the EPR spectra of Co(II) and Cu(II) porphyrins

Atanasov

Daul

Rohmer

et al. 2006

Chemical Physics Letters

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. dedicate this work to the memory of late Prof. A. Schweiger. AbstractUsing a DFT based Ligand Field treatment (LFDFT) of the electronic structure of Co(II) and Cu(II) porphyrins (CoP and CuP) we analyse the origin of their EPR spectra. From a comparison between theoretical result on Co model clusters (CoP and CoP-ZnP dimer) we conclude that the g-tensor values are very sensitive to the axial coordination which stabilizes a 2 A 1 ground state in good agreement with experimental data. In contrast, DFT overestimates Cu-ligand covalency, leading to large discrepancy with experiments, and hence the orbital contribution to the computed g-values is too small. Using a numerical adjustment of nuclear charge for Cu, a good agreement between the computed and the experimental g-tensor values is observed. The influence of the DFT functional on the calculated g-tensor is also discussed.

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Section: Introductionmentioning

confidence: 99%

A DFT based ligand field study of the EPR spectra of Co(II) and Cu(II) porphyrins

Atanasov

Daul

Rohmer

et al. 2006

Chemical Physics Letters

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“…Thus we have to compare the PtP structure with the well-studied Zn-porphyrin ͑ZnP͒ molecule. 27,45,47 The optimized geometries of PtP and ZnP are presented in Table III together with the PdP structure, which is the closest relative to platinum porphyrin.…”

Section: Resultsmentioning

confidence: 99%

Theoretical study of phosphorescence in dye doped light emitting diodes

Minaev

Jansson

Ågren

et al. 2006

The Journal of Chemical Physics

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Phosphorescence of platinum͑II͒ octaethyl porphyrin ͑PtOEP͒, which has been used in organic light emitting diodes to overcome the efficiency limit imposed by the formation of triplet excitons, is studied by time-dependent ͑TD͒ density functional theory ͑DFT͒. The spin-orbit coupling ͑SOC͒ effects and the phosphorescence radiative lifetime ͑ p r ͒, calculated by the TD DFT method with the quadratic response technique, are analyzed for a series of porphyrins in order to elucidate the internal heavy atom effect on p r . While the significance of the d orbital admixture into the lowest unoccupied molecular orbital e g ͑ * ͒, proposed by Gouterman et al. ͓J. Chem. Phys. 56, 4073 ͑1972͔͒, is supported by our SOC calculations, we find that the charge-transfer ͑CT͒ mechanism is more important; the CT state of the 3 A 2g symmetry provides effective SOC mixing with the ground state, and a large 3 A 2g -3 E u transition dipole moment gives the main contribution to the radiative phosphorescence rate constant. The IR and Raman spectra in the ground state and first excited triplet state ͑T 1 ͒ are studied for proper assignment of vibronic patterns. An orbital angular momentum of the T 1 state is not quenched completely by the Jahn-Teller effect. A large zero-field splitting is predicted for PtP and PtOEP which results from a competition between the SOC and Jahn-Teller effects. A strong vibronic activity is found for the e g mode at 230 cm −1 in PtP phosphorescence which is shifted to 260 cm −1 in PtOEP. This out-of-plane vibration of the Pt atom produces considerable change of the SOC mixing. The role of charge-transfer state of d * type is stressed for the explanation of the electroluminescent properties of the dye doped light emitting diode.

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“…[14] To the best of our knowledge, this is the first time such spectroscopic data of peramine are reported.…”

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confidence: 85%

A DFT/TD‐DFT study for the ground and excited states of peramine and some pyrrolopyrazinone compounds

Łapiński

Dubis

2009

J of Physical Organic Chem

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International audiencePeramine, a heterocyclic natural molecule, reveals two main, different in nature, electronic absorption bands. The theoretical calculations at TD-B3LYP/6-311++G(d,p) level of theory show that the electronic excitations are connected predominantly with pi-pi* and charge-transfer (CT) transitions. Excitation of electrons from the pyrrolopyrazinone ring to the side chain plays the role in creating CT transition. The character and energy of the first 30 singlet-singlet electronic transitions have been also investigated for the most stable conformation of peramine

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A DFT/TDDFT interpretation of the ground and excited states of porphyrin and porphyrazine complexes

Cited by 301 publications

References 65 publications

A DFT based ligand field study of the EPR spectra of Co(II) and Cu(II) porphyrins

A DFT based ligand field study of the EPR spectra of Co(II) and Cu(II) porphyrins

Theoretical study of phosphorescence in dye doped light emitting diodes

A DFT/TD‐DFT study for the ground and excited states of peramine and some pyrrolopyrazinone compounds

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