Vapor Spectra of Porphyrins

Mullins, John A.; Adler, Alan D.; Hochstrasser, Robin M.

doi:10.1063/1.1697158

Cited by 26 publications

(2 citation statements)

References 7 publications

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“…Tetraphenylporphyrin H 2 TPP and its metallo-complexes MTPP (M Ni, Cu, Zn, Pd, Ag, Cd) were synthesized according to known methods [16,17]. Substituted tetraphenylporphyrins H 2 T(R)PP (R 2-, 3-, 4-CH 3 ; 2-, 4-F; 2-, 3-, 4-Cl; 3-, 4-Br; 3,5-C(CH 3 ) 3 ) were synthesized according to Semeykin et al [18].…”

Section: Methodsmentioning

confidence: 99%

Thermodynamics of porphyrin sublimation

Perlovich

Голубчиков

Klueva

2000

J. Porphyrins Phthalocyanines

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The saturated vapor pressures of tetraphenylporphyrin H 2 TPP , its four-coordinated metallo-complexes MTPP ( M ≡ Ni , Cu , Zn , Pd , Ag , Cd ) and some phenyl-substituted derivatives H 2 T ( R ) PP ( R ≡ 2-, 3-, 4- CH 3; 2-, 4- F ; 2-, 3-, 4- Cl ; 3-, 4- Br ; 3,5- C ( CH 3)3) have been measured using the inert gas flow method. The values of sublimation enthalpy Δ sub H m and entropy Δ sub S m are calculated. On the basis of the kinetic vapor pressure dependence, the start temperatures of thermal destruction of the investigated porphyrins are determined. The temperatures of melting of the tetraphenylporphyrin metallo-complexes measured by the DSC method are in linear correlation with the Δ sub H m values. The correlation between the thermodynamic functions of porphyrin sublimation (Δ sub H m , Δ sub S m , Δ sub G m ) and the literature data on the crystal structure of the compounds is considered. The Δ sub H m values obtained by some authors by different methods are compared with the results of our investigations. Possible reasons for discrepancies in the results are discussed.

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Section: Methodsmentioning

confidence: 99%

Thermodynamics of porphyrin sublimation

Perlovich

Голубчиков

Klueva

2000

J. Porphyrins Phthalocyanines

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“…Square-planar complexes, including transition metal porphyrinic complexes, comprise an extremely important class of compounds, being at the center of numerous proteins, enzymes, and one-dimensional conductors. − Assignments of the simplest of these complexes, such as tetracyano complexes, have been well established. − The more complex porphyrinic complexes have had an accepted assignment of the two principal regions, the Q region in the long visible and the Soret region in the near UV, , but recent calculations have suggested that a change in assignments is appropriate. − Polarized electronic spectra have been helpful in making transition assignments, and we have proposed a new set of assignments for metallophthalocyanines (Mpc, where pc = tetraazatetrabenzoporphyrin) using a reduced-symmetry complex and results from earlier SCF-Xα-DOS calculations. − …”

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confidence: 99%

Polarized Specular Reflectance Spectra of Fe(β-dtpy)₂·4THF: AD₂_hModel of Porphyrins

et al. 1999

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Transition metal complexes of β-dtpy (1,2,6,7-tetracyano-3,5-dihydro-3,5-diiminopyrrolizinide) are spectrally similar to metallophthalocyanines (derivatives of porphyrin) but with the advantage of being D 2 h instead of D 4 h so that many degenerate electronic transitions are identifiable separately. We have prepared and characterized Fe(β-dtpy)2·4THF, whose crystal structure allows three spectral polarizations to be measured. We have assigned the visible and ultraviolet transitions that correspond to the Q and Soret regions of porphyrinic complexes; these assignments differ markedly from the traditional “four-orbital” model. The secondary Q peak (R) is a separate electronic transition rather than a vibronic component, and the Soret transition has been reassigned.

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