DFT study of core‐modified porphyrin isomers

Soujanya, Yarasi; Punnagai, M.; Bandaru, Sateesh; Sastry, G. Narahari

doi:10.1002/qua.21022

Cited by 4 publications

(3 citation statements)

References 53 publications

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“…The relaxed equilibrium DFT structures are presented in Figures and , and the corresponding structural parameters are shown in Tables and . The bond lengths and angles in the relaxed DFT structures of the monomers (Figure and Tables and ) are in good agreement with the respective X-ray crystal structures − and calculated structures in the literature. − A notable feature of the tin(IV) ion in monomer 9 is that it displayed a distorted octahedral geometry, where the O–Sn–O bond was tilted toward the mean plane of the macrocycle (Table ), which is also in agreement with X-ray crystal and computational structures. ,, …”

Section: Resultssupporting

confidence: 85%

Construction of Novel Cyclic Tetrads by Axial Coordination of Thiaporphyrins to Tin(IV) Porphyrin

et al. 2017

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We report the formation of new cyclic porphyrin tetrads 1 and 2, which were obtained from the reaction between dihydroxytin(IV) porphyrin and cis-dihydroxy-21-thiaporphyrin/21,23-dithiaporphyrin. The unique oxophilicity of tin(IV) porphyrin was the driving force for the formation of these tetrads. Moreover, these novel tetrads represent the first examples of cyclic porphyrins containing tin(IV) that are constructed exclusively on the basis of the "Sn-O" interaction without any other complementary, noncompetitive mode of interactions. The molecular structures of the cyclic tetrads have been investigated by matrix-assisted laser desorption ionization time-of-flight mass spectrometry, NMR spectroscopy, quantum-mechanical calculations, and, in one case, single-crystal X-ray crystallography. The X-ray structure revealed that the two cis-dihydroxy-NS porphyrins were coordinated at the axial positions of two tin(IV) porphyrins, leading to the symmetric cyclic tetrad structure. The optical properties of tetrads were studied, and these compounds were stable under redox conditions. Preliminary photophysical studies carried out on the tetrads indicated efficient energy transfer from tin(IV) porphyrin to the thiaporphyrin unit, which highlights their potential applications in energy and electron transfer in the future.

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Section: Resultssupporting

confidence: 85%

Construction of Novel Cyclic Tetrads by Axial Coordination of Thiaporphyrins to Tin(IV) Porphyrin

et al. 2017

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“…The electronic structure of parent porphycene 1 has been the subject of many studies that used various theoretical models. ,,,,,− Other porphycenes for which calculations have been performed include 1 -Mg; ,, 1 -Zn; 1 -Fe(II); 13 ; , 20 and 21 ; , 25 ; , 38 ; 73 , 74 , and 76 ; 122 ; 125 ; dibenzoporphycenes 169 (without methyl groups) , and 187 ; 169 -(Fe)II; and tetraoxaporphycene 165 …”

Section: Electronic Spectroscopymentioning

confidence: 99%

Spectroscopy and Tautomerization Studies of Porphycenes

2016

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Tautomerization in porphycenes, constitutional isomers of porphyrins, is strongly entangled with spectral and photophysical parameters. The intramolecular double hydrogen transfer occurring in the ground and electronically excited states leads to uncommon spectroscopic characteristics, such as depolarized emission, viscosity-dependent radiationless depopulation, and vibrational-mode-specific tunneling splittings. This review starts with documentation of the electronic spectra of porphycenes: Absorption and magnetic circular dichroism are discussed, together with their analysis based on the perimeter model. Next, photophysical characteristics are presented, setting the stage for the final part, which discusses the developments in research on tautomerism. Porphycenes have been studied in different experimental regimes: molecules in condensed phases, isolated in supersonic jets and helium nanodroplets, and, recently also on the level of single molecules investigated by optical and scanning probe microscopies. Because of the rich and detailed information obtained from these diverse investigations, porphycenes emerge as very good models for studying the complex, multidimensional phenomena involved in the process of intramolecular double hydrogen transfer.

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“…The introduction of substituents in meso‐position has been found to have great modification effects on the properties of porphyrin and has attracted considerable attention 17, 18. The peripheral substitution often brings about the distortion of porphyrin ring that could be classified as out‐of‐plane and in‐plane distortion.…”

Section: Introductionmentioning

confidence: 99%

Electronic structures and spectra of symmetric meso‐substituted porphyrin: DFT and TDDFT—PCM investigations

Venkataramanan¹,

Suvitha²,

Nejo³

et al. 2011

Int J of Quantum Chemistry

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DFT and TDDFT calculations at the level of PBE0/6-31G(d)/6-31þG (d) were performed systematically on seven porphyrins with symmetrical mesosubstitutents. Our results show that the planarity of the free base porphyrin (BP) are affected by the introduction of substitutents at the meso-position of the ring. Geometrical studies show that the introduction of electron-withdrawing groups brings about in-plane deformation in the porphyrin ring, whereas the bulky substitutents make an out-of-plane deformation. However, FMO's diagram shows that electronwithdrawing groups alter the degeneracy of the HOMO and HOMO À1 orbtial. Up on introduction of substituents at the meso-position, the Q band FMOs transitions were the same as in the case of free BP; however, the oscillator strength is changed. Electron releasing substituted at the meso-position shows bathochromic shift in the Q band region. However, the intensity or the hyperchromic shift is higher for the electron withdrawing groups. Solvation studies show that Q bands are blue shifted and B bands are red shifted, whereas the intensity of the B bands was highly enhanced compared with the Q bands. These theoretical studies would be helpful in designing new porphyrins for the photodynamic therapy and dye-sensitized solar cell applications.

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DFT study of core‐modified porphyrin isomers

Cited by 4 publications

References 53 publications

Construction of Novel Cyclic Tetrads by Axial Coordination of Thiaporphyrins to Tin(IV) Porphyrin

Construction of Novel Cyclic Tetrads by Axial Coordination of Thiaporphyrins to Tin(IV) Porphyrin

Spectroscopy and Tautomerization Studies of Porphycenes

Electronic structures and spectra of symmetric meso‐substituted porphyrin: DFT and TDDFT—PCM investigations

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