Pigment Solution Research Articles

Construction and Optimization of the Dye Sensitization Solar Cell Using a Au Particle and a Natural Vegetable Pigment

Au nanoparticles dispersion liquid and the pokeweed pigment solution respectively showed the maximum absorption wavelength at visible region by UV-vis absorption spectrum. The conversion efficiency of DSSC which was assembled with Au+TiO2 film and TiO2 film was respectively 0.0529 % and 0.0167 %. The difference in this conversion efficiency depends on magnitude relation of the short circuit photocurrent density. Charge transfer resistance decreases by adding the Au nanoparticles which are a metal to TiO2 which is a semiconductor, and it is thought that short circuit photocurrent density increased. In addition, it is thought that this is because the excitation of the pigment became easy to happen by reinforced light electric field occurred by the plasmon absorption of metal nanoparticles. The improvement of the conversion efficiency was confirmed, but performance is largely low in comparison with general DSSC. Using ac impedance measurement, the resistance ingredient in the cell is identified.

Photosensitizing properties of supramolecular systems based on chlorin e6

The novel supramolecular systems based on chlorine e 6 (Ce 6 ) are presented, and their optical absorption and fluorescence have been investigated. The influence of different excipients as poly-N-vinylpyrrolidone (PVP), polyethyleneglycol (PEG), bovine serum albumin (BSA), chitosan, Triton X-100 (TX-100) on spectral characteristics of these systems has been studied. The obtained spectral-fluorescence characteristics of Ce 6 -PVP, Ce 6 -PEG, Ce 6 -BSA, Ce 6 -TX-100 indicate disaggregation of chlorine e 6 molecules and their consecutive interaction with excipients in solutions and formation of molecular associates and molecular complexes. The system Ce 6 -chitosan is characterized by aggregation of pigments in solution that reduces photochemical activity of a photosensitizer. The fluorescence quantum yield j k of mentioned above supramolecular systems has been calculated. The results can be useful during the new method of controlled aggregation of photosensitizers as a part of supramolecular complexes development as well as for the purposes of new medicines of predictable photodynamic activity creation.

Construction and Optimization of the Dye Sensitization Solar Cell Using a Au Particle and a Natural Vegetable Pigment

Light of the sun is inexhaustible and clean. The study of the solar cell using light of the sun is currently conducted. Dye sensitization solar cell (DSSC) uses a metal complex having rare and expensive ruthenium (Ru), or organic dye. Therefore, in this study, a pigment from a naturally occurring plant for cost reduction was extracted and was used for sensitizing dye. However, the conversion efficiency of DSSC made using a nature plant pigment is low. Therefore, with reinforced light electric field occurred by the plasmon absorption of metal nanoparticles, the improvement of the conversion efficiency of DSSC using the natural plant pigment was tried. In this session, current density-voltage (i-V) characteristics is reported with construction of DSSC which put Au nanoparticles and the natural plant pigment together.In a 100 mL measuring flask, HAuCl4·4H2O, trisodium citrate dihydrate, and NaBH4 was added to this order to become 0.2 mM, 0.7 mM and 0.3 mM each. Au nanoparticles dispersion liquid was prepared in this way, and was added for triethylene glycol to become 30 vol%. In addition, polyethylene glycol, TiO2, and the sodium dodecyl sulfate aqueous solution were added for this Au nanoparticles dispersion liquid. Resulted mixture was sonicated. The paste, which was prepared by the method mentioned above, was applied on conductive face of an ITO substrate by the squeegee method. Substrate casted was calcined at 500 degrees Celsius for 1 hour. A layer prepared on ITO substrate was assumed as AuTiO2 film. On the other hand, after crushing a grape pericarp or 5 g of Phytolacca americana fruit in the mixer with "an aqueous solution which included 0.993 % by volume TFA in methanol 63.8 % by volume (63.8 vol% acidization methanol)", resulting mixture was filtered, centrifuged, and supernatant solution was provided with pigment solution. TiO2 film on ITO substrate was immersed in the pigment solution which was extracted, and was left at rest in a cool incubator of 5 degrees Celsius for 1 day. After dipping for 1 day, a substrate was washed in ultra-pure water and was dried in air. TiO2 film which was manufactured from the paste which did not include Au nanoparticles dispersion liquid. The AuTiO2 film and the TiO2 film modified with pigment were used as a working electrode. The ITO substrate which sputtered Pt was used as a counter electrode. Using these working and counter electrode, i-V characteristics was measured under the halogen bulb irradiation that transmitted a UV cut filter and a heat-rays absorption filter.By the UV-vis absorption spectrum in the pigment solution which was extracted from Phytolacca americana fruit and Kyoho grape pericarp, the maximum absorption wavelengths was confirmed about two pigment solution in a visible light region of 541 nm and 532 nm, respectively. In addition, in DSSC using the pigment that was extracted from Phytolacca Americana, as a result of i-V characteristics measurement, Light energy conversion efficiency and short circuit photocurrent density of approximately 2.4 times of DSSC using the pigment extracted from Kyoho grape were confirmed. As for this, a hydroxyl group of the TiO2 surface and one of the anthocyanin-based pigment forms hydrogen bonding in DSSC using Kyoho grape pigment, but it is thought that this is because electron transfer from the pigment to TiO2 was performed more effectively than a case of Kyoho grape because the carboxy group of the Betalain series dye and the hydroxyl group of the TiO2surface form ester bond in DSSC using the Phytolacca americana pigment. At present, to identify a nature pigment, structure analysis are being examined.Au nanoparticles dispersion liquid and the Phytolacca Americana pigment solution respectively showed the maximum absorption wavelength of 526 nm and 549 nm by UV-vis absorption spectrum. The conversion efficiency of DSSC which was assembled with AuTiO2 film and TiO2 film was respectively 0.05287 % and 0.01669 %. The difference in this conversion efficiency depends on magnitude relation of the short circuit photocurrent density. Charge transfer resistance decreases by adding the Au nanoparticles which are a metal to TiO2 which is a semiconductor, and it is thought that short circuit photocurrent density increased. In addition, it is thought that this is because the excitation of the pigment became easy to happen by reinforced light electric field occurred by the plasmon absorption of metal nanoparticles. The improvement of the conversion efficiency was confirmed, but performance is largely low in comparison with general DSSC. Therefore, by ac impedance measurement, the resistance ingredient in the cell is identified and the construction condition of the cell is being examined.

Gamma-irradiation effect on a commercial composite anticorrosive pigment and acidity-to-alkalinity conversion

ABSTRACTA commercial composite anticorrosive pigment based on aluminum dihydrogen tripolyphosphate was studied after exposure to gamma irradiation (Co60, 0, 20, 50, 100 and 150 kGy) using FTIR, XRD, TGA and acid-base titration technologies. Although the FTIR spectra showed that the effect of the irradiation on functional groups in the pigments was not obvious, the decrease in the crystal lattice parameters of the irradiated pigments was observed in the XRD spectra compared to the non-irradiated sample. But the extent of the lattice parameter decrease monotonically with the increase of absorbed dose from 20 to 150 kGy, which was attributed to the decomposition of water and the simultaneous occurrence of lattice damage when the pigments were exposed to gamma rays. Of particular significance was the displayed basicity of the aqueous solutions of the irradiated pigments compared to the acidity of the solution of the non-irradiated pigment, which was attributed to the decomposition of P-OH groups (combined water).

Transparent quasi-solid state dye-sensitized solar cells sensitized with naturally derived pigment extracted from red seaweed

Red seaweeds collected at Kefallinia Greek Island are examined for the first time as possible sensitizers in third generation photovoltaic cells. In particular, red seaweeds were collected and different solvents were used to extract their pigment through a simple procedure, in order to be used as a natural sensitizer for dye-sensitized solar cells. The dye solution with enhanced absorption in the visible spectrum was submitted to further absorption tests, where different pH and dye solution's temperature were tested to determine whether it affects the amount of the adsorbed dye on nanocrystalline TiO2 films. Solutions made with natural dye extracted from red algae in different solvents were used for the sensitization of TiO2 photoanodes and fabrication of quasi-solid state dye-sensitized solar cells some of which exhibited very satisfactory results compared with the published values so far of other seaweed dyes. The solar cells were examined in terms of J–V characteristic curves under simulated solar illumination and the best performing ones were also tested under dark conditions, while electrochemical impedance spectroscopy was used to evaluate electrodes and electrolyte interfaces. The optimal results were obtained for an acidic dye solution (pH = 3) and for pigment's solution temperature of 35 °C where cells showed a short circuit current density of 1.26 mA/cm2 and an open-circuit voltage of 0.66 V.

Response surface optimization of purification process for pigment from Coreopsis tinctoria by macroporous resins

To optimize the purification process of pigments from Coreopsis tinctoria with macroporous resins by establishing second regression model with response surface methodology. The experiment showed that XDA-7 resin had the best purification effect for pigments from C. tinctoria. The optimal absorption conditions for pigments from C. tinctoria were determined as follows： concentration of pigments solution 2.7 g•L⁻¹, flow rate 6 mL•min⁻¹, pH 6. Under these conditions, the absorption rate of pigments was up to 94.16%. Optimal desorption conditions were as follows： ethanol concentration 64%, flow rate 5 mL•min⁻¹, elution dosage 4 BV. Under these conditions, pigment desorption rate was as high as 98.72%.

Particle Size, Morphology and Color Characteristics of C.I. Pigment Red 57:1 : 1. Effect of Synthesis Conditions

The effects of synthesis conditions on characteristics of the calcium-azo complex pigment, C.I. Pigment Red 57:1, were studied. It was mainly considered that the industrially required synthesis conditions for lowering electrical conductivity of the pigment solution keeping pigment quality such as particle size and color characteristics. Three parameters were chosen as control factors during the synthesis. The first was the amount of hydrochloric acid added to transform sodium nitrite into nitrous acid. The second was the amount of calcium chloride added to insolubilize the synthesized azo dye. The final factor was pH control during the coupling reaction. The electrical conductivity and pigment aggregate particle size were dependent on the amount of hydrochloric acid and calcium chloride. Higher HCl concentration gave brighter yellowish-red color because of smaller particle aggregate size and narrower size distribution. Amount of charged ions in the synthesis process might affect the lake formation resulting different particle aggregate size and color shade.

Pigment violet 19 - a test case to define a simple method to simulate the vibronic structure of absorption spectra of organic pigments and dyes in solution.

A typical quinacridone pigment, PV19, has been used to analyze the impact of several computational parameters on the UV/vis absorption band shape in solution, simulated using density functional theory and time-dependent density functional theory levels of approximation. These encompass, (i) the choice of exchange-correlation functional, (ii) the basis set, (iii) the method for non-equilibrium optimization of the excited state geometry, (iv) the approach for evaluating the vibronic band structure, (v) the peak broadening, and (vi) the scaling of the harmonic vibrational frequencies. Among these, the choice of exchange-correlation functional is certainly of the most importance because it can drastically modify the spectral shape. In the case of PV19, the M05-2X and to a lesser extent CAM-B3LYP XC functionals are the most efficient to reproduce the vibronic structure, confirming the important role of exact Hartree-Fock exchange. Still, these functionals are not the most reliable to predict the excitation energies and oscillator strengths, for which M05, a functional with less HF exchange, performs better. For evaluating the vibronic structure, the simple gradient method, where only one step of geometry optimization of the excited state is carried out and the gradients are used to evaluate the Huang-Rhys factors as well as to determine the excited state geometries produces a spectrum that is very similar to the ones obtained with the more involved Duschinsky and geometry methods, opening the way to a fast simulation of the UV/vis absorption spectra of pigments and dyes. Then, the effect of scaling the calculated vibrational frequencies to account for anharmonicity effects as well as for limitation of the method also impacts the shape of the vibronic spectrum and this effect depends on the method used to determine the Huang-Rhys factors. Indeed, scaling the vibrational frequencies by a factor which is typically smaller than 1.0 results in a relative decrease of the 0-1 peak intensity with respect to the 0-0 band when optimizing the geometry of the excited state whereas the effect is opposite and magnified if using the gradient method.

Dichromatism causes color variations in leaves and spices

AbstractAlthough the color phase (hue) of plants plays fundamental roles in quality of foods and horticultural species, principles of variations in hues of plant materials are neither fully understood nor extensively examined by researchers. This may be partly because plant colors are determined by complex physicochemical factors non‐understandable to most biologists. For example, hue of soluble pigment has been demonstrated to change at different thickness of a layer or pigment concentrations in exceptional substances such as pumpkin seed oil. Such strange effect (dichromatism) of layer thickness on pigment hue was previously explained by application of Beer–Lambert law on absorbance spectra (Naturwissenschaften 2007;94:935–939). In this report, we demonstrate dichromatism in plant leaves and red spices. Dichromatism of these materials can be quite simply observed by extraction and dilution of pigments with dimethylformamide, a scarcely evaporating organic solvent. Hue of pigment solutions gradually changed with dilution from green to yellow‐green for leaves, and from red to yellow for spices. These changes were also explained by changes in absorbance spectra with dilution, nevertheless spectra of absorption coefficient were stable. Dichromatism in leaves caused uniform negative correlation between lightness and hue in any plant species examined. Such correlation was successfully explained by calculation with a normalized RGB color matching function. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 605–611, 2015

Utilizing Extracted Fungal Pigments for Wood Spalting: A Comparison of Induced Fungal Pigmentation to Fungal Dyeing

The lengthy time periods required by current spalting methods prohibit the economically viable commercialization of spalted wood on a large scale. This work aimed to compare the effects of induced spalting in 16 Pacific Northwest woods using three common spalting fungi, Chlorociboria aeruginosa, Scytalidium cuboideum, and Scytalidium ganodermophthorum, with the significantly less time-consuming treatment of these woods using dichloromethane-extracted green, red, and yellow pigments from the same fungi. For pigment extracts, the dosage required for a pigment to internally color various wood species to 30% internal coverage was investigated. With few exceptions, treatment with pigment extracts outperformed induced spalting in terms of percent internal color coverage. Cottonwood consistently performed best with all three pigment solutions, although chinkapin performed as well as cottonwood with the red pigment, and Port Orford cedar performed as well with the yellow pigment. While no wood species showed 30% internal color coverage with the green pigment solution, a number of additional species, including pacific silver fir, madrone, dogwood, and mountain hemlock showed internal color coverage on the order of 20–30% for red and/or yellow. Cottonwood was determined to be the best suited wood species for this type of spalting application.

مطالعه اثرات غلظت های مختلف محلول ساکارز بر ویژگی های کمی وکیفی برش های خشک شده گلابی با محلول های باز تغلیظ شده اسمزی

Food dehydration process in several reasons, causes deteriorate qualitative characteristics in final products. It is necessary to use some pretreatments such as osmotic dehydration. In this research, during osmotic dehydration of pear rings, the effects of concentration of sucrose solutions of 50 and 60 percent (w/w), in constant temperature of 30oC, and reconstitution of osmotic solutions (until 5 times), were investigated on quantitative and qualitative characteristics of osmotic samples, such as pH, hardness, color of texture, total sugar and moisture content of osmotic samples and pH, turbidity, viscosity of solution osmotic. The result showed that with increase concentration osmotic solution and reconstitution of osmotic solutions pH of sample and solution is increase and decrease respectively. It’s because of increase the moisture content and extraction acids from texture of osmotic sample. Also reconstitutions of osmotic solutions will cause increase the turbidity in solution, that reason is increase the production of pigment in solution. Also increases the density of osmotic solutions may cause increase the color of osmotic samples and we can say that the reason is extraction of colorful compound from texture of sample. The most reason of hardness of texture is related to a sample that it processed in a solution that is 5 times concentrated. Finally the coated sample that was osmotic dehydrated and fifth reconstituted solution was known as the superior sample.

Spectral and kinetic parameters of phosphorescence of triplet chlorophyll a in the photosynthetic apparatus of plants.

Spectral and kinetic parameters and quantum yield of IR phosphorescence accompanying radiative deactivation of the chlorophyll a (Chl a) triplet state were compared in pigment solutions, greening and mature plant leaves, isolated chloroplasts, and thalluses of macrophytic marine algae. On the early stages of greening just after the Shibata shift, phosphorescence is determined by the bulk Chl a molecules. According to phosphorescence measurement, the quantum yield of triplet state formation is not less than 25%. Further greening leads to a strong decrease in the phosphorescence yield. In mature leaves developing under normal irradiation conditions, the phosphorescence yield declined 1000-fold. This parameter is stable in leaves of different plant species. Three spectral forms of phosphorescence-emitting chlorophyll were revealed in the mature photosynthetic apparatus with the main emission maxima at 955, 975, and 995 nm and lifetimes ~1.9, ~1.5, and 1.1-1.3 ms. In the excitation spectra of chlorophyll phosphorescence measured in thalluses of macrophytic green and red algae, the absorption bands of Chl a and accessory pigments - carotenoids, Chl b, and phycobilins - were observed. These data suggest that phosphorescence is emitted by triplet chlorophyll molecules that are not quenched by carotenoids and correspond to short wavelength forms of Chl a coupled to the normal light harvesting pigment complex. The concentration of the phosphorescence-emitting chlorophyll molecules in chloroplasts and the contribution of these molecules to chlorophyll fluorescence were estimated. Spectral and kinetic parameters of the phosphorescence corresponding to the long wavelength fluorescence band at 737 nm were evaluated. The data indicate that phosphorescence provides unique information on the photophysics of pigment molecules, molecular organization of the photosynthetic apparatus, and mechanisms and efficiency of photodynamic stress in plants.

ChemInform Abstract: Previous and Recent Advances in Pyranoanthocyanins Equilibria in Aqueous Solution

AbstractReview: 49 refs.

Ergodicity, configurational entropy and free energy in pigment solutions and plant photosystems: Influence of excited state lifetime

We examine ergodicity and configurational entropy for a dilute pigment solution and for a suspension of plant photosystem particles in which both ground and excited state pigments are present. It is concluded that the pigment solution, due to the extreme brevity of the excited state lifetime, is non-ergodic and the configurational entropy approaches zero. Conversely, due to the rapid energy transfer among pigments, each photosystem is ergodic and the configurational entropy is positive. This decreases the free energy of the single photosystem pigment array by a small amount. On the other hand, the suspension of photosystems is non-ergodic and the configurational entropy approaches zero. The overall configurational entropy which, in principle, includes contributions from both the single excited photosystems and the suspension which contains excited photosystems, also approaches zero. Thus the configurational entropy upon photon absorption by either a pigment solution or a suspension of photosystem particles is approximately zero.

Vibrational and electronic spectroscopy of the retro-carotenoid rhodoxanthin in avian plumage, solid-state films, and solution

Rhodoxanthin is one of few retro-carotenoids in nature. These chromophores are defined by a pattern of single and double bond alternation that is reversed relative to most carotenoids. Rhodoxanthin is found in the plumage of several families of birds, including fruit doves (Ptilinopus, Columbidae) and the red cotingas (Phoenicircus, Cotingidae). The coloration associated with the rhodoxanthin-containing plumage of these fruit dove and cotinga species ranges from brilliant red to magenta or purple. In the present study, rhodoxanthin is characterized in situ by UV–Vis reflectance and resonance Raman spectroscopy to gain insights into the mechanisms of color-tuning. The spectra are compared with those of the isolated pigment in solution and in thin solid films. Key vibrational signatures are identified for three isomers of rhodoxanthin, primarily in the fingerprint region. Electronic structure (DFT) calculations are employed to describe the normal modes of vibration, and determine characteristic modes of retro-carotenoids. These results are discussed in the context of various mechanisms that change the electronic absorption, including structural distortion of the chromophore or enhanced delocalization of π-electrons in the ground-state. From the spectroscopic evidence, we suggest that the shift in absorption is likely a consequence of perturbations that primarily affect the excited state of the chromophore.

Fluorescent colored material made of clay mineral and phycoerythrin pigment derived from seaweed

In order to obtain a fluorescent colored powder, composites of phycoerythrin pigment extracted from seaweed and clays (hectorite and montmorillonite) were examined. The pigment adsorbed easily on synthetic hectorite in an aqueous solution and a composite with bright fluorescence was obtained. On the other hand, the adsorption of the pigment on natural montmorillonite was not sufficient, and a salt had to be added to the pigment solution to obtain the composite. Low heat and light fastness, which are serious drawbacks of phycoerythrin for practical usage, were increased by the adsorption to the hectorite clay.

Simultaneous Analysis of the Coloring Compounds in Indigo, Phellodendron bark, and Madder Dye Using HPLC-DAD-MS

Indigotin, indirubin, berberine, palmatine, alizarin, and purpurin are major pigments of indigo plant, Phellodendron bark, and madder. The six pigments were examined using the HPLC-DAD-MS instrument for the purpose of the simultaneous detection of the pigments in a single sample run. The HPLC-DAD-MS method examined the individual pigment solutions in DMSO, a solution containing 6 pigments, and the DMSO extract of the silk dyed with a dye solution of 5 pigments excluding indirubin. The retention times of the HPLC chromatograms, of the uv-vis absorption bands in the DAD analyses, and the molecular ions detected for the compound peaks in the MSD analyses were consistent throughout the analyses of individual pigment solutions, mixed pigment solutions, and dye extracted from silk dyeing. The developed instrumental method of the simultaneous detection of six pigments can identify dye in an exhumed textile if the textile is dyed using any one (or multiple) pigments of indigo, Phellodendron bark, or madder plant.

The molecular second hyperpolarizability of the light-harvesting chlorophyll a/b pigment-protein complex of photosystem II.

Photosynthetic structures when imaged with nonlinear optical microscopy give rise to high third harmonic generation (THG) signal intensity due to the presence of chlorophylls and xanthophylls which have large second hyperpolarizabilitiy (γ) values. The γ value of trimers of the light-harvesting chlorophyll a/b pigment-protein complex of photosystem II (LHCII) isolated from pea (Pisum sativum) plants was investigated by the THG ratio technique at 1028 nm wavelength and found to have the value (-1600 ± 400) × 10(-41) m(2) V(-2). The large negative γ value of trimeric LHCII is due to the presence of chlorophyll a and chlorophyll b which have large negative γ values, while positive γ values of xanthophylls reduce the magnitude of the THG signal. Variation was observed between the measured γ value of LHCII and the approximated γ value of LHCII obtained by adding individual γ values of chlorophylls and xanthophylls. This difference can be attributed to the differing inter-pigment interactions of oriented chlorophylls and xanthophylls in the pigment-protein complex compared to randomly oriented non-interacting pigments in solution, as well as a differing dielectric environment of the pigments within LHCII versus the surrounding organic solvent.

Study of the Enhancement of Cell Performance of Dye Sensitized Solar Cells Sensitized With Nephelium lappaceum (F: Sapindaceae)

We have studied the performance of dye sensitized solar cells sensitized with pigments extracted from the fruit sheath of Nephelium lappaceum (F: Sapindaceae). The pH of the pigment solution used for impregnation was controlled by adding concentrated HCl (50:0.2 v/v). The UV-Vis spectroscopic results revealed that the extract consists of the pigment of Anthocyanin, with an additional absorption peak appearing around 540 nm at a lower pH of the pigment solution. Also the band gap of the pigment was reduced by 1 eV at low pH conditions. The solar cells fabricated with pigment extracted from the fruit sheath of Nephelium lappaceum showed photo-response with the conversion efficiency of 0.26%, with an open-circuit voltage (VOC) of 453 mV, short-circuit current density (ISC) of 1.17 mA cm−2, and fill factor (ff) of 0.48. The conversion efficiency was significantly enhanced when pH of the pigment solution was lowered by adding concentrated HCl. The conversion efficiency of the dye sensitized solar cells (DSSCs) sensitized after HCl treatment of the pigment was increased to 0.56%, with an open-circuit voltage (VOC) of 404 mV, short-circuit current density (ISC) of 2.71 mA cm−2, and fill factor (ff) of 0.35. The HOMO level of the pigment at low pH was shown to be shifted towards more positive values with respect to vacuum level, giving rise to an enhanced DSSC efficiency. The overall efficiency enhancement of the low pH pigment was due to the combined effect of increased UV-Vis absorption and efficient adsorption of dye molecules onto the TiO2 semiconductor surface.

Spectroscopic study on formation of aggregated structures by carotenoids: Role of water

Formation of molecular aggregate structures of β-carotene and zeaxanthin, by means of evaporation from pigment solutions in organic solvent was studied with UV–Vis absorption, FTIR and resonance Raman techniques. Pigment solutions were prepared in CHCl3 and CCl4 both dehydrated and hydrated with trace amounts of water. Formation of the aggregated structures characterized by either strong-coupling (e.g. zeaxanthin in hydrated CHCl3) or weak-coupling (e.g. β-carotene in hydrated CHCl3) has been observed. FTIR analysis and molecular modeling showed that H2O molecules can be bound to the aggregated structures formed by zeaxanthin in the form of molecular bridges, predominantly between the terminal hydroxyl groups of adjacent molecules (stabilized by strong hydrogen bonds), but also between the polyene chains (by means of the π-type weak hydrogen bonds). Resonance Raman analysis revealed that the structures formed with the presence of H2O molecules are characterized by twisting of the polyene backbone. The effect of twisting is observed particularly in the case of zeaxanthin structures deposited from hydrated CHCl3 and is not observed in the case of the structures of β-carotene deposited from dehydrated CCl4. Involvement of water molecules in stabilizing aggregated structures of carotenoids is postulated.