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Frackowiak D, Bauman D, Manikowski H, Browett WR, Stillman MJ. Circular dichroism and magnetic circular dichroism spectra of chlorophylls a and b in nematic liquid crystals. II. Magnetic circular dichroism spectra. Biophys Chem 2008; 28:101-14. [PMID: 17010293 DOI: 10.1016/0301-4622(87)80079-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/1987] [Revised: 07/22/1987] [Accepted: 07/23/1987] [Indexed: 11/24/2022]
Abstract
Absorption and magnetic circular dichroism (MCD) spectra are reported for chlorophyll (Chl) a and Chl b dissolved in nematic liquid crystal solvents. The spectra were measured with the dye molecules oriented uniaxially along the direction of. the magnetic field and measuring light beam. It is significant that under such conditions the MCD spectra recorded in the wavelength region of the Q and Soret bands of the chlorophyll are essentially unchanged with respect to rotation of the sample cell around this axis, even though there is almost complete orientation of the chlorophyll molecules by the liquid crystals. The MCD spectra of Chl a and b in the nematic liquid crystal solvents used in this study are surprisingly similar to the spectra obtained under isotropic conditions. These results illustrate an important technique with which to examine the optical spectra of dyes oriented in liquid crystal matrices in which the anisotropic effects can be reduced the negligible proportions by the application of a strong magnetic field parallel to the direction of the measuring light beam. The first deconvolution calculations are reported that describe the deconvolution of pairs of absorption and MCD spectra, in the Q and B band regions, for both Chl a and b. The spectral analysis to obtain quantitative estimates of transition energies was accomplished by carrying out detailed deconvolution calculations in which the both the absorption and MCD spectral envelopes were fitted with the same number of components; each pair of components had the same hand centres and bandwidth values. This procedure resulted in an assignment of each of the main transitions in the absorption spectra of both Chl a and b. Chl a is clearly monomeric, with Qy, Qx, By and Bx located at 671, 582, 439 and 431 nm, respectively. Analysis of the spectral data for Chl b located Qy, By and Bx, at 662, 476 and 464 nm, respectively.
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Affiliation(s)
- D Frackowiak
- Institute of Physics, Poznan Technical University, Piotrowo 3, 60-965 Poznan, Poland
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2
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Arcioni A, van Zandvoort MAMJ, Bartolini P, Torre R, Tarroni R, Righini R, Zannoni C. Effective Shape and Dynamics of Chlorophyll a in a Nematic Liquid Crystal. J Phys Chem B 1998. [DOI: 10.1021/jp9726504] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Alberto Arcioni
- Dipartimento di Chimica Fisica e Inorganica, Università degli Studi di Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy, LENS (European Laboratory for Non-linear Spectroscopy), Università, Largo E. Fermi 2, I-50125 Firenze, Italy, and Dipartimento di Chimica, Università, Via G. Capponi 9, I-50121 Firenze, Italy
| | - Marc A. M. J. van Zandvoort
- Dipartimento di Chimica Fisica e Inorganica, Università degli Studi di Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy, LENS (European Laboratory for Non-linear Spectroscopy), Università, Largo E. Fermi 2, I-50125 Firenze, Italy, and Dipartimento di Chimica, Università, Via G. Capponi 9, I-50121 Firenze, Italy
| | - Paolo Bartolini
- Dipartimento di Chimica Fisica e Inorganica, Università degli Studi di Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy, LENS (European Laboratory for Non-linear Spectroscopy), Università, Largo E. Fermi 2, I-50125 Firenze, Italy, and Dipartimento di Chimica, Università, Via G. Capponi 9, I-50121 Firenze, Italy
| | - Renato Torre
- Dipartimento di Chimica Fisica e Inorganica, Università degli Studi di Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy, LENS (European Laboratory for Non-linear Spectroscopy), Università, Largo E. Fermi 2, I-50125 Firenze, Italy, and Dipartimento di Chimica, Università, Via G. Capponi 9, I-50121 Firenze, Italy
| | - Riccardo Tarroni
- Dipartimento di Chimica Fisica e Inorganica, Università degli Studi di Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy, LENS (European Laboratory for Non-linear Spectroscopy), Università, Largo E. Fermi 2, I-50125 Firenze, Italy, and Dipartimento di Chimica, Università, Via G. Capponi 9, I-50121 Firenze, Italy
| | - Roberto Righini
- Dipartimento di Chimica Fisica e Inorganica, Università degli Studi di Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy, LENS (European Laboratory for Non-linear Spectroscopy), Università, Largo E. Fermi 2, I-50125 Firenze, Italy, and Dipartimento di Chimica, Università, Via G. Capponi 9, I-50121 Firenze, Italy
| | - Claudio Zannoni
- Dipartimento di Chimica Fisica e Inorganica, Università degli Studi di Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy, LENS (European Laboratory for Non-linear Spectroscopy), Università, Largo E. Fermi 2, I-50125 Firenze, Italy, and Dipartimento di Chimica, Università, Via G. Capponi 9, I-50121 Firenze, Italy
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5
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Frackowiak D, Zelent B, Malak H, Cegielski R, Goc J, Niedbalska M, Ptak A. Interactions between chlorophyll a and beta-carotene in nematic liquid crystals. Biophys Chem 1995; 54:95-107. [PMID: 7756570 DOI: 10.1016/0301-4622(94)00118-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Fluorescence lifetime in the ps range, polarized absorption, polarized fluorescence spectra and delayed luminescence time resolved spectra were measured for chlorophyll a solutions with and without beta-carotene addition in nematic liquid crystal. Photoacoustic spectra of the same samples at various frequencies of light modulation were also taken. The frequency dependence of the photoacoustic spectra suggests that part of the excitation is converted into heat in a slow process (with a decay time of the order of ms). The lifetime results suggest that at used concentration some aggregation of the chlorophyll a occurs. The chlorophyll a molecules interact strongly with the beta-carotene forming some nonfluorescent or weakly fluorescent aggregates characterized by having various thermal deactivation yields and orientations in anisotropic matrix when compared to those of separated pigments. It seems that the aggregated forms of the chlorophylls are partially disrupted as a result of the their interaction with the beta-carotene. Singlet excitation of beta-carotene is not transferred to the fluorescent form of chlorophyll a. Delayed (in microsecond time range) luminescence of chlorophyll a is quenched by beta-carotene. This luminescence is located in the same spectral region as prompt fluorescence. Interactions between chlorophyll a and beta-carotene depend on the degree of pigment orientation and their aggregation.
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Affiliation(s)
- D Frackowiak
- Institute of Physics, Poznań University of Technology, Poland
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7
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Wróbel D, Kozielski M. Resonance Raman spectra of chlorophylls dissolved in liquid crystal matrices. Biophys Chem 1989; 33:127-32. [PMID: 17010925 DOI: 10.1016/0301-4622(89)80015-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/1988] [Revised: 10/24/1988] [Accepted: 12/15/1988] [Indexed: 11/18/2022]
Abstract
Polarized resonance Raman spectra of chlorophyll (Chl) b oriented in a mixture of p-methoxybenzylideno-p'-butylaniline (MBBA) and p-ethoxybenzylideno-p'-butylaniline (EBBA) have been measured. The spectra have been analyzed and the second- and fourth-rank order parameters and the orientational distribution function of Chl b are presented.
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Affiliation(s)
- D Wróbel
- Institute of Physics, Poznań Technical University, Piotrowo 3, 60-965 Poznań, Poland
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8
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Wróbel D, Kozielski M. Resonance Raman spectra of chlorophylls dissolved in liquid crystal matrices. Biophys Chem 1988; 29:309-15. [PMID: 17010916 DOI: 10.1016/0301-4622(88)85053-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/1987] [Revised: 10/14/1987] [Accepted: 11/27/1987] [Indexed: 11/24/2022]
Abstract
The molecular ordering of molecules embedded in a uniaxial liquid crystalline system has been considered. In particular, planar Chl a molecules in an MBBA + EBBA mixture have been studied by using polarized resonance Raman spectroscopy. The second- and fourth-rank order parameters and the orientational distribution function of Chl a in the nematic MBBA + EBBA liquid crystalline phase are discussed.
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Affiliation(s)
- D Wróbel
- Institute of Physics, Poznań Technical University, Piotrowo 3, 60-965 Poznań Poland
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12
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Chapados C, Germain D, Leblanc RM. Aggregation of chlorophylls in monolayers. Biophys Chem 1980; 12:189-98. [PMID: 17000150 DOI: 10.1016/0301-4622(80)80051-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/1979] [Indexed: 11/28/2022]
Abstract
The nature of the interaction between the chlorophyll a molecules in multilayer arrays obtained by the Langmuir-Blodgett technique is examined by electronic and infrared spectroscopies. Following the deposition of the multilayers, we observed a blue shift with time in the electronic spectra. This effect is monitored by infrared spectroscopy. The intensity of the coordinated ketone band is decreased while the intensity of the free ketone band is increased. These modifications are explained by the reorganization of the chlorophyll a molecules from an organized to a less organized one. The influence of H2O, D2O and SO2 vapors on the chlorophyll a multilayers give some informations on the role of water molecules in the aggregation of chlorophyll a in this ordered system. From these observations, a model is proposed for the multilayer arrangement implying two molecules of water per molecule of chlorophyll a.
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Affiliation(s)
- C Chapados
- Groupe de Recherche en Biophysique, Département de Chimie-Biologie, Université du Québec à Trois-Rivierés, Trois-Rivières, Quebéc, Canada, G9A SH7
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13
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Bauman D, Wrobel D. Dichroism and polarized fluorescence of chlorophyll a, chlorophyll c and bacteriochlorophyll a dissolved in liquid crystals. Biophys Chem 1980; 12:83-91. [PMID: 17000146 DOI: 10.1016/0301-4622(80)80042-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/1979] [Revised: 01/03/1980] [Indexed: 11/21/2022]
Abstract
Three photosynthetic pigments were studied: chlorophyll a, chlorophyll c and bacteriochlorcphyll a in nematic liquid crystal matrixes. The polarized absorption and fluorescence spectra as a function of the electric field have been measured. From the polarized components of the absorption A( parallel) and A( perpendicular) of the pigments in liquid crystals two reduced components A(x) and A(y) are calculated (x and y are the direction of the axis which is going through the second, fourth pyrrol rings, and the first, third rings, respectively). From these results the orientation of chlorophylls in liquid crystals and the configuration of the transition moments in the skeleton of the pigment molecules were determined.
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Affiliation(s)
- D Bauman
- Institute of Physics, Poznan Technical University, 60-965 Poznan, Poland
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14
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Salamon Z, Martyński T. Influence of chlorophyll a on intermolecular interactions in liquid crystal. Biophys Chem 1979; 9:369-73. [PMID: 16997202 DOI: 10.1016/0301-4622(75)80051-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/1978] [Revised: 01/31/1979] [Indexed: 10/18/2022]
Abstract
Studies of the variability of the spectral properties (linear dichroism, polarized fluorescence and the energetic separation of the absorption and emission bands) of chlorophyll a in a nematic liquid crystal matrix with respect to the effects of solute concentration and the external electric fields were made. A close examination of the above mentioned types of variability suggest that the pigment molecules can influence a high initial order of the liquid crystal matrix. These structural changes of the matrix can be explained by the assumption that two types of chlorophyll with different orientations occur: the surface layers with the high degree of orientation, and a central volume of the sample with disordered molecules. The ordered molecules are sensitive to an reorientation by the external electric field.
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Affiliation(s)
- Z Salamon
- Institute of Physics, Poznań Technical University, 61-965 Poznań, Poland
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