Spectroscopic studies of tetrabenzoporphyrins: MgTBP, ZnTBP and H2TBP

Ehrenberg, Benjamin; Johnson, Fred M.

doi:10.1016/0584-8539(90)80066-8

Cited by 33 publications

(22 citation statements)

References 26 publications

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“…31,42,[44][45][46][47] Determination of the HOMO and LUMO orbitals yields similar structure to that observed here in the solid-state. The D 2h symmetry of TBP, versus D 4h symmetry in the metal-substituted molecules, is known to lift the molecular orbital degeneracy, as also shown here in the solid-state for k between Z-Γ-Y.…”

Section: B Relation To Single Molecule Calculationssupporting

confidence: 64%

“…In the MTBP bandstructures reported here the degeneracy is indicative of the high degree of symmetry in the molecules (D 2h for TBP and D 4h for Cu-, Ni-, and ZnTBP) and in the monoclinic unit cell. 14,47 It is noted in the E vs. k diagrams that the dispersion is very low and the bandgap large between k=Y-A and E-C, indicating planes of least molecular orbital overlap. In the metal-substituted MTBPs examined here the variation in band-splitting may be indicative of slightly changed molecularly symmetry or planarity, as expected from calculations on single-molecule forms of metalloporphyrins.…”

Section: Discussionmentioning

confidence: 99%

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Ab initio electronic structure calculations of solid, solution-processed metallotetrabenzoporphyrins

Shea

Kanicki

2012

Journal of Applied Physics

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An ab initio study of the electronic structures of solid metallotetrabenzoporphyrins (MTBPs) utilized in organic transistors and photovoltaics is presented. Bandstructures, densities of states, and orbitals are calculated for H 2 , Cu, Ni, and Zn core substitutions of the unit cell of solid TBP, as deposited via soluble precursors that are thermally annealed to produce polycrystalline, semiconducting thin-films. While the unit cells of the studied MTBPs are nearly isomorphous, substitution of the core atoms alters the structure of the bands around the energy bandgap and the composition of the densities of states. Cu and Ni core substitutions introduce nearly-dispersionless energy bands near the valence and conduction band edges, respectively, that form acceptor or deep generation/recombination states. The following article appeared in J. Appl. Phys. 111, 073709 (2012).

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Section: B Relation To Single Molecule Calculationssupporting

confidence: 64%

Section: Discussionmentioning

confidence: 99%

Ab initio electronic structure calculations of solid, solution-processed metallotetrabenzoporphyrins

Shea

Kanicki

2012

Journal of Applied Physics

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“…The lower extinction coefficient (relative to MgTBP) [40] of the Soret band in H 2 TBP at λ4385 (Fig. 11) must be attributed to its lack of intrastate vibrational coupling.…”

Section: The Soret Band Of H 2 Tbpmentioning

confidence: 99%

“…1) and the free-base variety, H 2 TBP [40][41][42]. These highly stable, abiotic molecules belong to a sub-class of a larger category of molecules known as, "porphyrins and metalloporphyrins" [43][44][45].…”

Section: Proposed Solutionmentioning

confidence: 99%

Diffuse interstellar bands: A comprehensive laboratory study

Johnson

2006

Spectrochimica Acta Part A: Molecular and Biomolecular Spectros

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As a result of the search for the identity of the chromophores responsible for producing the diffuse interstellar bands, a comprehensive exposition of experimental data is presented, which implicates the following molecules: 1. The extremely stable organic molecules, magnesium tetrabenzoporphyrin (MgTBP) and H 2 TBP. 2. A paraffin matrix (referred to as "grains") containing TBPs. 3. A low concentration of pyridine (also within the grains), whose transmission window at 2175Å, accounts for the ubiquitous UV bump. The blue emission spectra associated with the central star, HD44179, of the Red Rectangle displays the fluorescence excitation spectra of bare MgTBP. This unique spectrum matches the low temperature lab data of MgTBP in the vapor phase. An effective grain temperature of 2.728 K (+/-0.008) was deduced, based on MgTBP's lowest measured vibrational state of 341 GHz.

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“…The same value as well as a similar band shape were also observed for H 2 TBP in DMSO. A noticeable change in the shape of the absorption band in the 580-620 nm region is observed in solvents such as n-octane (ΔE S 2 S 1 ≈ 1480 cm -1 ) [17] and in a mixture of tetrahydrofuran and ether [18], where the most intense feature is the short-wavelength component of the complex structure in the 580-620 nm range. New information on the spectral characteristics is obtained from H 2 TBP molecules whose inhomogeneous broadening is partially removed in their low-temperature absorption spectra in the solid N 2 matrix (Fig.…”

Section: Absorptionmentioning

confidence: 99%

Electronic spectroscopy, stimulated emission, and persistent spectral hole burning of cryogenic nitrogen matrices doped with tetrabenzoporphin

Arabei

Galaup

McCaffrey

et al. 2012

Low Temperature Physics

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This paper deal with our on-going work on the electronic spectroscopy of tetrapyrrole molecules embedded in cryogenic hosts. Under nanosecond laser excitation of the free-base tetrabenzoporphin molecules in a nitrogen matrix at 8 K, increasing the laser pulse energy results in essential enhancement of the intensity of one or several vibronic emission lines to take place in the fine-structure fluorescence spectrum. The observed intense monochromatic radiation possesses characteristics of stimulated radiation being realized as a result of a transition from the purely electronic S 1 level to a vibrational sublevel of the S 0 state, corresponding to excitation of stretching C-C vibrations of the tetrapyrrole methane bridges. We also report on persistent spectral hole-burning effects. The analysis of the holes and antiholes formation gives some insight on the photochemical properties of tetrabenzoporphin in a nitrogen matrix.

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Spectroscopic studies of tetrabenzoporphyrins: MgTBP, ZnTBP and H2TBP

Cited by 33 publications

References 26 publications

Ab initio electronic structure calculations of solid, solution-processed metallotetrabenzoporphyrins

Ab initio electronic structure calculations of solid, solution-processed metallotetrabenzoporphyrins

Diffuse interstellar bands: A comprehensive laboratory study

Electronic spectroscopy, stimulated emission, and persistent spectral hole burning of cryogenic nitrogen matrices doped with tetrabenzoporphin

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