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Гладков, Л. Л.; Konstantinova, V. K.; Ksenofontova, N. M.; Sokolov, N. A.; Соловьев, К. Н.; Shkirman, S. F.

doi:10.1023/a:1015355507800

Cited by 3 publications

(11 citation statements)

References 14 publications

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“…For instance DFT results indicate that the intense IR modes in the 1100 to 1200 cm À1 range arise from the IP bending modes of the aryl ring-C-H bonds. This finding is supported by the pronounced isotope shifts observed by Gladkov et al 29 in the Raman spectra of ZnPc-d 16 in KBr pellets.…”

Section: B Dft Calculations Datasupporting

confidence: 70%

Infra-red and Raman spectroscopy of free-base and zinc phthalocyanines isolated in matrices

Murray

Dozova

McCaffrey

et al. 2010

Phys. Chem. Chem. Phys.

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The infrared absorption spectra of matrix-isolated zinc phthalocyanine (ZnPc) and free-base phthalocyanine (H 2 Pc) have been recorded in the region from 400 to 4000 cm À1 in solid N 2 , Ar, Kr and Xe. Raman spectra have been recorded in doped KBr pellets. The isotopomers HDPc and D 2 Pc have been synthesised in an attempt to resolve the conflicting assignments that currently exist in the literature for the N-H bending modes in H 2 Pc spectra. A complete correlation between the vibrational modes of the three free-base isotopomers and ZnPc has been achieved. Comparison of the IR and Raman spectroscopic results, obtained with isotopic substitution and with predictions from large basis set ab initio calculations, allows identification of the in-plane (IP) and out-of-plane (OP) N-H bending modes. The largest IP isotope shift is observed in the IR at 1046 cm À1 and at 1026 cm À1 in Raman spectra while the largest effect in the OP bending modes is at 764 cm À1 . OP bending modes are too weak to be observed in the experimental Raman data. The antisymmetric N-H stretching mode is observed at B3310 cm À1 in low temperature solids slightly blue shifted from, but entirely consistent with the literature KBr data. With the exception of the N-H stretches, the recorded H/D isotope shifts in all the N-H vibrations are complex, with the IP bending modes exhibiting small n H /n D ratios (the largest value is 1.089) while one of the observed OP modes has a ratio o 1. DFT results reveal that the small ratios arise in particular from strong coupling of the N-H IP bending modes with IP stretching modes of C-N bonds. The unexpected finding of a n H /n D ratio smaller than one was analysed theoretically by examining the evolution of the frequencies of the free base by increasing the mass from H to D in a continuous manner. A consequence of this frequency increase in the heavier isotopomer is that the direction of the N-D OP bend is reversed from the N-H OP bend.

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Section: B Dft Calculations Datasupporting

confidence: 70%

Infra-red and Raman spectroscopy of free-base and zinc phthalocyanines isolated in matrices

Murray

Dozova

McCaffrey

et al. 2010

Phys. Chem. Chem. Phys.

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“…We should point out that the interpretation of the resonance Raman spectra and the vibronic spectra proposed by our group based on the classical calculations of the normal vibrations in [2] is consistent on the whole with the results obtained for the quantum chemical calculations by the DFT method. (When comparing, we must consider that in [2], the mode of vibrations is given based on the potential energy distribution of the vibrations). However, there are also discrepancies.…”

supporting

confidence: 83%

“…We assign the PtPc line at 1196 cm -1 [9] to a B 1g vibration, which for ZnPc has a frequency of about 1180 cm -1 . Considering the good agreement between the calculated and experimental frequencies of the skeletal bending vibrations (see Table 1), we can say that the line at 642 cm -1 (B 1g ) [2] does not correspond to the fundamental frequency. The same is possibly also true for the 826 cm -1 line [10], although we cannot rule out the possibility that it correlates with the calculated frequency 849 cm -1 .…”

mentioning

confidence: 71%

“…This especially pertains to the separations of the normal vibrations into B 1g and B 2g symmetry types. In contrast to [2], we assign the depolarized lines in the resonance Raman spectra at 1214, 1473, and 1608 cm -1 to B 2g vibrations, while we assign the 1584 cm -1 line to a B 1g vibration. We assign the PtPc line at 1196 cm -1 [9] to a B 1g vibration, which for ZnPc has a frequency of about 1180 cm -1 .…”

mentioning

confidence: 87%

“…In [2], the resonance Raman spectra of Znphthalocyanine (ZnPc) and its isotopically substituted derivative ZnPc-d 16 are obtained. The experimental data are compared with the results of the normal vibration calculation using a valence force field.…”

mentioning

confidence: 99%

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Interpretation of resonance Raman spectra of Zn-phthalocyanine and Zn-phthalocyanine-d16 based on the density functional method

Гладков¹,

Gromak

Konstantinova

2007

J Appl Spectrosc

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We have used the density functional method (DFT) to calculate the geometric structure and the frequencies of even (gerade) vibrations of the Zn-phthalocyanine and Zn-phthalocyanine-d 16 molecules, and we have refined the interpretation of the resonance Raman spectra and the fine-structure fluorescence spectra. We observed a dependence of the frequencies of both stretching and bending vibrations of the aza bridges on the nature of the central metal atom.Introduction. Many scientific publications have been devoted to study of the physicochemical properties of phthalocyanine molecules and their analogs because of their broad application in science and technology. An important part of such investigations has been study of the vibrational and vibronic states of compounds in this class to establish correlations between spectra and structure and to develop methods for monitoring and diagnostics of the state of these compounds in technical devices. This is possible after detailed interpretation of the corresponding spectra.The review paper [1] provides discussion of the results of theoretical and experimental work up to 2002 on interpretation of the spectra of phthalocyanine and its metal complexes. In [2], the resonance Raman spectra of Znphthalocyanine (ZnPc) and its isotopically substituted derivative ZnPc-d 16 are obtained. The experimental data are compared with the results of the normal vibration calculation using a valence force field. The calculated data describe satisfactorily the changes in the spectrum upon deuteration. Moreover, for some normal vibrations there are significant discrepancies between the calculated and experimental values of the frequencies. Furthermore, within the D 4h symmetry point group, to which the ZnPc molecule belongs, we cannot use polarization data to separate vibrations of B 1g and B 2g symmetry. Vibrations of these symmetries appear in the resonance Raman spectra as depolarized lines. For ZnPc and ZnPc-d 16 , the calculations showed that a number of normal vibrational frequencies of these symmetries are close. Therefore assignment of the corresponding frequencies requires additional testing.The Calculation. Recently the quantum mechanical density functional method has been successfully used for calculation of the vibrations of macrocyclic molecules of the porphyrin type (see, for example, [3,4]).In order to refine the interpretation, we did the calculations for the equilibrium geometry of the ZnPc and ZnPc-d 16 molecules and their vibrational frequencies by the indicated method, using two exchange-correlation functionals BPE and BLYP with the help of the algorithm proposed in [5] and realized within the quantum chemical program in [6]. The geometry calculation began with an asymmetric structure, but during optimization for ZnPc we obtained an equilibrium configuration belonging to the D 4h symmetry point group with the Zn atom in the plane of the molecule. Its deviation from the plane was 5⋅10 -4 Å, although initially it was equal to 0.4 Å. Then we calculated the force constants and...

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Raman and Luminescent Spectra of Sulfonated Zn Phthalocyanine Enhanced by Gold Nanoparticles

et al. 2017

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Sulfonated Zn phthalocyanine, as a prospective photosensitizer in the photodynamic therapy of tumors, is investigated by means of Raman, infrared, and fluorescence spectroscopies. Conventional and surface-enhanced spectra from this photosensitizer are obtained and compared. Gold nano-islands attached to silica cores (Au-SiO2) are proposed as nanostructures providing plasmonically enhanced signals. Pronounced enhancement of Raman and infrared spectral bands from sulfonated Zn phthalocyanine allows their more convenient assignment with vibrational modes of sulfonated Zn phthalocyanine. In comparison to Raman and IR, the fluorescence is less enhanced by Au-SiO2 particles.

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Cited by 3 publications

References 14 publications

Infra-red and Raman spectroscopy of free-base and zinc phthalocyanines isolated in matrices

Infra-red and Raman spectroscopy of free-base and zinc phthalocyanines isolated in matrices

Interpretation of resonance Raman spectra of Zn-phthalocyanine and Zn-phthalocyanine-d16 based on the density functional method

Raman and Luminescent Spectra of Sulfonated Zn Phthalocyanine Enhanced by Gold Nanoparticles

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