Depolarization dispersion curves of resonance Raman fundamentals of metalloporphyrins and metallophthalocyanines subject to asymmetric perturbations

Zgierski, Marek Z.; Pawlikowski, M.

doi:10.1016/0301-0104(82)85209-9

Cited by 56 publications

(66 citation statements)

References 33 publications

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“…First, they affect the electronic states of the porphyrin by additional mixing of the four-orbital states. Asymmetric perturbations of the porphyrin structure may cause mixing of the above electronic states [8]. This can be accounted for by expanding the pure electronic Hamiltonian r el with respect to the above SNCDs " q…”

Section: Depolarization Ratio Dispersion As a Probe Of Asymmetric Dismentioning

confidence: 99%

“…A careful analysis of resonance excitation profiles (REPs) based on suitable quantum mechanical models is required for obtaining the coupling parameters which contain information about electronic and structural properties of the porphyrin's ground and excited electronic states. In the presence of asymmetric distortions, additional structural information can be derived from the measurement and analysis of the depolarization ratio dispersion (DRD) of Raman lines assignable to vibrations of the porphyrin skeleton [8].…”

Section: Introductionmentioning

confidence: 99%

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Polarized resonance Raman dispersion spectroscopy on metalporphyrins

Schweitzer‐Stenner

2001

J. Porphyrins Phthalocyanines

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ABSTRACT:Resonance Raman spectroscopy is an ideal tool to investigate the structural properties of chromophores embedded in complex (biological) environments. This holds particularly for metalporphyrins which serve as prosthetic group in various proteins. Resonance Raman dispersion spectroscopy involves the measurement of resonance excitation and depolarization ratios of a large number of Raman lines at various excitation energies covering the spectral region of the chromophore's optical absorption bands. Thus, one obtains resonance excitation profiles and the depolarization ratio dispersion of these bands. While the former contains information about the structure of excited electronic states involved in the Raman scattering process, the latter reflects asymmetric perturbations which lower the porphyrin macrocycle symmetry from ideal D 4h . The article introduces and compares different quantum mechanical approaches designed to quantitatively analyze both resonance excitation and the relationship between symmetry lowering and depolarization ratio dispersion.

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Section: Depolarization Ratio Dispersion As a Probe Of Asymmetric Dismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Polarized resonance Raman dispersion spectroscopy on metalporphyrins

Schweitzer‐Stenner

2001

J. Porphyrins Phthalocyanines

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“…Thus, they clearly deviate from their D 4h -expectation values, which do not depend on the choice of the excitation wavelength [43]. Shelnutt as well as Zgierski and Pawlikowski explained these dispersions in terms of electronic and vibronic perturbations, which will be explained below [55,56]. A systematic investigation of Raman depolarization ratio dispersions and resonance excitation profiles of various heme proteins was subsequently in our research group at the University of Bremen [57][58][59][60].…”

Section: Asymmetric Deformations Of the Functional Heme Groupmentioning

confidence: 94%

“…While Γ does not depend on the chosen normal vibration, the derivative of this potential in (2) is different for each Raman active vibration. Following Zgierski and Pawlikowski, we call this contribution vibronic perturbation [56].…”

Section: Asymmetric Deformations Of the Functional Heme Groupmentioning

confidence: 99%

Cytochrome c: A Multifunctional Protein Combining Conformational Rigidity with Flexibility

Schweitzer‐Stenner

2014

New Journal of Science

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Cytochrome has served as a model system for studying redox reactions, protein folding, and more recently peroxidase activity induced by partial unfolding on membranes. This review illuminates some important aspects of the research on this biomolecule. The first part summarizes the results of structural analyses of its active site. Owing to heme-protein interactions the heme group is subject to both in-plane and out-of-plane deformations. The unfolding of the protein as discussed in detail in the second part of this review can be induced by changes of pH and temperature and most prominently by the addition of denaturing agents. Both the kinetic and thermodynamic folding and unfolding involve intermediate states with regard to all unfolding conditions. If allowed to sit at alkaline pH (11.5) for a week, the protein does not return to its folding state when the solvent is switched back to neutral pH. It rather adopts a misfolded state that is prone to aggregation via domain swapping. On the surface of cardiolipin containing liposomes, the protein can adopt a variety of partially unfolded states. Apparently, ferricytochrome c can perform biological functions even if it is only partially folded.

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“…The direct product (E, × E u) contains the Alg , Aeg, Big and B2g representations, and therefore modes with these symmetries are enhanced. Studies of resonance Raman spectra of phthalocyanines and porphyrins [28][29][30] show that the B-term scattering is very strong in spectra excited in the Q-band region. We assume that ZnPc spectra show similar characteristics and B-term scattering is effective in spectra excited in resonance with the Q absorption band.…”

Section: Raman Spectramentioning

confidence: 99%