Absorption Intensity Ratio Research Articles

Changing absorption intensity ratios for methylene violet Bernthsen in normal alcohols and at different temperatures

Absorption spectra of methylene violet Bernthsen (MVB) are reported, obtained in normal alcohols, methanol through 1-octanol, and at different temperatures, 15 °C to 75 °C. Two distinct absorption intensities are apparent. The 565 nm intensity increases relative to the 598 nm intensity as alcohol chain length increases. For each solvent, increasing temperature causes similar intensity ratio effects. Computational spectra of MVB in methanol indicates a decrease in hydrogen-bonding as temperature increases with a corresponding loss of intensity in the low energy peak consistent with the experimental observations. Hydrogen-bonding is indicated as playing a role in the alcoholic solvent effects.

A multi-mode self-referenced optical thermometer based on low-doped YVO4: Eu3+ phosphor

In recent years, the continued development of optical thermometry has become a hot topic of interest for researchers, due to its advantages of non-contact and non-invasive temperature measurement. The optical thermometry is based on the different photophysical properties or changes in luminescent parameters of luminescent materials to reflect temperature. Further, the development of multi-mode optical thermometers can effectively expand the practical application rang of the temperature measurements. Here, we monitored various temperature sensitive luminescence characteristics of YVO4: Eu3+ phosphor by testing its temperature-dependent photoluminescence (PL) spectra, photoluminescence excitation (PLE) spectra, and luminescence decay curves. We successfully realized a multi-mode optical thermometer based on the luminescence intensity ratio, absorption intensity ratio, the thermally induced behavior of the charge transfer band, and luminescent transition probability (A) of the host material. Different temperature measurement strategies were evaluated and compared in terms of relative sensitivity (Sr) and temperature uncertainty (ΔT). Notably, the Sr of the rarely used temperature measurement strategy based on the A of host luminescence was the optimal among the studied strategies with 2.03% K−1, corresponding to a ΔT of 0.5 K. The results suggest that YVO4: Eu3+ phosphor has potential applications in self-referential optical thermometry.

Exploring the excitation spectrum behavior of Dy in CaWO4 for a new excited-state-based ratiometric thermometry

Exploring excited-state transition behavior is of great importance for understanding the optical characteristics of lanthanide ions, which may potentially develop new optical thermometry by the thermally affected excitation processes. In this work, we explore the detailed excitation transition behaviors of Dy3+ and propose a new thermometry strategy based on excited-state absorption intensity ratio (EIR) in Dy3+ doped CaWO4 phosphors. The optimal Dy3+ doping concentration in CaWO4:Dy phosphors was determined and its fine excitation transition lines from low-lying levels of 6HJ (J = 15/2, 13/2, 11/2, and 9/2) to the respective high-lying levels of Dy3+ ions were identified by well-resolving the photoluminescence excitation (PLE) spectra. By taking advantage of the opposite trends of temperature-dependent PLE intensities of Dy3+, a new ratiometric thermometry based on the EIR of Dy3+ was proposed to be independent of the excitation wavelength and only excitation peak intensities required, with the merit of high absolute and relative sensitivities, excellent repeatability and reusability, good excitation wavelength selectivity. These findings demonstrated an effective strategy for developing a Dy3+-based EIR luminescent thermometer, as well as the enormous potential of Dy3+ doped CaWO4 phosphors in temperature sensing.

One-step rapid colorimetric detection of K+ using silver nanoparticles modified by crown ether.

Urinary potassium is an important parameter in clinical health diagnosis. Rapid and convenient detection of potassium ions (K+) in urine is essential for personal healthcare and health management. Here, crown ether (4-aminodibenzo-18-crown-6, ADC) modified silver nanoparticles (ADC-Ag NPs) were successfully prepared for one-step rapid colorimetric detection of urinary potassium. The detection mechanism is as follows: due to the matching sizes of the diameter of K+ and the cavity in crown ether 6, K+ is encapsulated between the cavities of two crown ethers, resulting in the clumping of ADC-Ag NPs and the color of the solution being altered. The colorimetric detection method has a fast response and is completed within 20 minutes. It also shows good selectivity and interference immunity. The lowest detectable concentration is 20 μM with the naked eye and 2.16 μM for UV-vis absorption spectroscopy. A good linear relationship (R2 = 0.9931) between the absorption intensity ratio and K+ concentration (0-100 μM) indicates that this colorimetric probe can be used to detect K+. The method was also applied for quantitative analysis of K+ in real urine samples with recovery between 116 and 120%.

A theoretical framework for optical thermometry based on excited-state absorption and lifetimes of Eu3+ compounds

Ratiometric optical thermometers correspond to one of the most extensively studied applications of luminescent lanthanide materials in recent years. Even though several systems were studied involving the Eu3+ ion, few of them explore the absorption from the low-lying 7F1 excited state and its dependence on the ligand field (LF) splitting. This work aims to describe various absorption intensity ratios (AIR) that can be built from the excitation or absorption spectrum of the europium (III) ion by using the absorptions from the 7F0 → 5D0 transition and the different ligand field components of the magnetic-dipole allowed 7F1 → 5D0 transition and the influence of the ligand field strength on the relative thermal sensitivity of such AIR constructions. We have shown that several AIR formulas can be obtained, and they can display opposite behaviors concerning the Ligand Field strength, being suitable for different compounds of non-cubic symmetries. In addition, the ligand field influence on the relative thermal sensitivity obtained by the lifetime thermometry of the Eu3+5D0 level has also been explored.

Optical characteristics of Tl+ centers in CsCaCl3, KCaCl3, and CsCl crystals

We have investigated the absorption, luminescence, and excitation spectra of the Tl+ centers in CsCaCl3:Tl+, KCaCl3:Tl+, and CsCl:Tl+ crystals in the energy region up to the vacuum ultraviolet region. The A, B, and C absorption bands attributed to the intra-ionic transitions were observed in the transparent energy region below their respective fundamental absorption edge. The parameters characterizing the Tl+ centers were estimated by the energy positions of the A, B, and C absorption bands and the absorption intensity ratio of the C to A bands. These values are consistent with those of the Tl+ centers in other ionic chloride crystals. The luminescence bands attributed to the radiative transitions from several relaxed excited states were observed even under excitation of the A absorption band. Although the intensities of the luminescence bands change with an increase in temperature from low temperature, the total integrated luminescence intensity remained almost constant. The temperature dependence of the luminescence intensity can be explained by the thermally activated non-radiative transitions among the relaxed excited states and the radiative transitions from them. By including the Tl+ centers in alkali and ammonium chloride crystals, the features of the Tl+ centers in the resulting chloride compound crystals have been comprehensively discussed regardless of the different chloride-ionic configurations around the Tl+ ions.

Translating cancer exosomes detection into the color change of phenol red based on target-responsive DNA microcapsules

Emerging evidence indicates that exosomes can be used as a potential biomarker for monitoring diseases, including cancer. However, enhancing the sensing performance in terms of convenience and sensitivity remains an urgent demand for exosomes detection. In this study, a pH-sensitive colorimetric biosensing strategy was developed for exosomes detection by integrating stimuli-responsive DNA microcapsules and acetylcholinesterase to produce acetic acid. The constructed DNA microcapsules consisted of DNA shells crosslinked by anti-CD63 aptamers and loaded with acetylcholinesterase. With exosomes addition, an energetically stabilized aptamer-CD63 compound was produced and microcapsules dissociated due to the reaction of surface protein CD63 of exosomes and aptamer of CD63, resulting in the release of encapsulated AChE. Through a simple centrifugation separation, unreacted DNA microcapsules were removed and the supernatant containing released acetylcholinesterase collected, which was then used for colorimetric exosomes detection through the ability of acetylcholinesterase to hydrolyze acetylcholine to release acetic acid. The resulting decreased solution pH was detected with phenol red indicator, with the sharp color transition conveniently by naked eye. Exosomes quantification was also achieved using the solution's absorption intensity ratio of 558 vs. 432 nm. The linear range was from 2.0 × 103 to 5.0 × 105 particles/μL, and the limit of detection and limit of quantification were 1.2 × 103 particles/μL and 2.2 × 103 particles/μL, respectively. In addition, this proposed strategy for exosomes detection showed a relative standard deviation of 3.1% and high recovery efficiency (>94%), exhibiting a bright application future in exsomes analysis.

Rapid and Application-Tailored Assessment Tool for Biogenic Powders from Crustacean Shell Waste: Fourier Transform-Infrared Spectroscopy Complemented with X-ray Diffraction, Scanning Electron Microscopy, and Nuclear Magnetic Resonance Spectroscopy.

Due to their chemical composition, richness in calcium carbonate, chitin, proteins, and pigments, and nanoporous structure, crustacean shell waste shows great potential for a wide variety of applications. Large quantities of waste shells are produced annually, meaning that they can be considered a renewable source of ecofriendly biogenic materials, which can be turned into value-added byproducts. In this paper, an IR-based technique is developed to differentiate various biogenic powders originated from crude or food-processed crustacean shells. The validity of the method is supported by cross-checking with XRD, NMR, and SEM–EDX analyses. Our goal was to determine changes in properties of waste crab shells after the two most common treatments, deproteinization and milling. We discovered that deproteinization with NaOH could be tracked from the IR absorbance intensity ratio of the υ(CH2,3) and υasym(CO32–) bands while milling time less influenced this ratio but induced changes in powder particle size distribution and morphology. The relative organic/inorganic ratio was different for different colored shells. Unexpectedly, waste shells stored for an average of 6 months or more were found to contain hydrated calcium carbonate (monohydrocalcite), which was absent in equivalent fresh shell composition. Deproteinization caused changes in mechanical properties of shells, making them more brittle, which resulted in a larger fraction of fine particles after powdering.

Dual-signal uric acid sensing based on carbon quantum dots and o-phenylenediamine

Fluorescent carbon quantum dots (CQDs), which showed excitation-dependent emission characteristics, were prepared using a facile hydrothermal method. The structure and optical properties of CQDs were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, UV–Vis spectroscopy, and fluorescence spectroscopy. These CQDs also showed peroxidase-like activity and could catalyze the H2O2-mediated oxidation of o-phenylenediamine (OPD) to form 2,3-diaminophenazine (DAP) with an absorption peak at 420 nm. DAP exhibited an obvious fluorescence emission at 550 nm under the excitation of 360 nm. On the other hand, it decreased the fluorescence of CQDs at 450 nm via inner filter effect. The experimental results indicated that the H2O2 concentration affected the color of DAP and the fluorescence intensity of CQDs and DAP. Thus, a colorimetric and ratiometric fluorescence dual-signal method was established for measuring the concentrations of H2O2 and uric acid (UA). The effects of pH, incubation temperature, incubation time, and OPD concentration on the response were investigated. Under the conditions of pH 7.5, temperature 50 °C, incubation time 30 min, and OPD 1.5 mM, the absorbance and fluorescence intensity ratio responses were linearly dependent on UA concentration ranging from 5.0 μM to 100 μM. The limits of detection were 0.7 and 0.5 μM with a colorimetric method and ratiometric fluorescence method, respectively. More importantly, this dual responsive method has been applied to the determination of UA in urine samples with satisfactory results.

Preparation parameters of polyaniline/polyvinyl chloride flexible wires for electrical conductivity performance analysis based on orthogonal arrays

ABSTRACT A flexible polyaniline/polyvinyl chloride (PVC) polymer conductive wire was prepared using flexible PVC polymer as the substrate by the swelling – in-situ polymerization method, the line-shaped dents were pressed on the substrate by the thermodynamic pre-deformation treatment technology. Based on the orthogonal test method, the effects of five main influencing factors – swelling time (A), swelling temperature (B), oxidation temperature (C), oxidation time (D), and oxidant concentration (E) – on the conductivity of the prepared polyaniline/PVC conductive wire was investigated. The results of the orthogonal array testing were subjected to range analysis and analysis of variance (ANOVA), and the influencing factors, in terms of significance, follow the order of swelling temperature, oxidation time, swelling time, oxidation temperature, and oxidant concentration, with the optimal factor-level combination being A2B2C2D2E2, which led to a desirable conductivity up to 1.19 × 10−1 S/cm. In addition, the influence of different conductive line size characteristics on the molecular structure, microstructure, and conductivity of polyaniline/PVC flexible conductive wire was further studied. On the microstructure, as the line width increases, the infrared absorption intensity ratio of the quinone ring and the benzene ring in the polyaniline/PVC conductive wires gradually approaches 1. The microstructure, as the line width of the polyaniline/PVC conductive wire increases, the formed polyaniline gradually changes from flakes and granules to fibrous strips and entangles with each other to form a spatial network structure. The conductivity of the wire increases with the increase of its width up to 1.48 × 10−1 S/cm.

Aptamer-Based Colorimetric Probe for trans-Zeatin Detection Using Unmodified Gold Nanoparticle.

Trans-Zeatin is the major active phytohormone in immature corn kernels. Herein, a highly sensitive, good selective and simple aptamer-based colorimetric method for the detection of trans-zeatin was constructed. The selected aptamer sequence binds with trans-zeatin and induces a duplex-to-aptamer structure switching. The gold nanoparticles (AuNPs) solution is stable with high-concentration salt, which is protected by red complementary DNA. In the absence of trans-zeatin, the color of AuNPs changed from red to blue because aptamer DNA and complementary DNA form double-stranded DNA. Thus, the ratio of absorbance intensities (A522/A650) of AuNPs is changed with the concentration of trans-zeatin. The color change could be observed by the naked eye. The linear range of this method covers a large variation of trans-zeatin concentration from 0.05 to 0.75 μM. The detection limit is 0.037 μM. Moreover, this method was applied successfully to detect trans-zeatin in real plant samples.

A novel colorimetric and fluorometric probe for biothiols based on MnO2 NFs-Rhodamine B system

Herein, a novel bimodal ratiometric probe for sensitive and selective detection of biothiols (including glutathione (GSH), cysteine (Cys) and homocysteine (Hcys)) was constructed, which was based on the redox reaction between manganese dioxide nanoflakes (MnO2 NFs) and rhodamine (RhB) and biothiols. When MnO2 NFs was added into RhB solution, RhB was oxidized to a series of derivatives, accompanying with the colorimetric color changing from purple to light pink and fluorescence changing from red to green. In the presence of GSH, Cys or Hcys, they could reduce MnO2 NFs to Mn2+, thereby preventing the following oxidization of RhB and the corresponding color and fluorescence changes. The absorption intensity ratio and fluorescence intensity ratio showed good linear relationships with the concentrations of biothiols. The colorimetric detection limits for GSH, Cys and Hcys were 0.057 μM, 0.140 μM and 0.087 μM, respectively. And the fluorescence detection limits were 0.177 μM, 0.282 μM and 0.161 μM. More importantly, this probe was successfully applied to monitor the concentration of GSH/Cys/Hcys in human serum samples, with satisfactory recovery. Thus, this MnO2 NFs-RhB platform can potentially be a candidate for the detection of biothiols.

Effect of Nd2O3 and Na2O concentration on physical and spectroscopic properties of TeO2–Bi2O3–ZnO–Na2O–Nd2O3 glasses

Two series of tellurite glasses with molar compositions of (55TeO2–2Bi2O3–(41-x) ZnO–2Na2O–xNd2O3 (x = 0.5, 1.0, 1.5, 2.0 and 2.5) and 55TeO2–2Bi2O3–(41-x) ZnO-xNa2O-2Nd2O3 (x = 1.0, 2.0, 3.0, 4.0, 5.0) were fabricated using melt quenching technique. Based on the measured densities, refractive indices and absorption spectra, physical and spectroscopic properties of these two-glass series are evaluated and compared. Whereas substitution of ZnO by Nd2O3 causes the values of density and refractive index increase, the substitution of ZnO by Na2O has been shown to impact the glass density and refractive index in the opposite manner. Molar volume of both series increases with an increase of either Nd2O3 or Na2O concentrations. In this regard, a dynamical model explaining the density and molar volume was proposed. Additionally, Judd-Ofelt theory was applied in order to predict the physical and laser properties of the two glasses series as a function of glass compositions, i.e., Judd-Ofelt parameters Ωt (t = 2, 4, 6), branching ratios (β), calculated lifetimes (τ), the emission to exited state absorption intensity ratio (Aem/AESA) and spectroscopic quality χ = Ω4/Ω6. Equations to relate χ with branching ratios for laser transitions 4F3/2 to 4IJ’ (with J′ = 9/2, 11/2, 13/2 and 15/2) were also derived.

Prostate and breast cancer cells death induced by xanthohumol investigated with Fourier transform infrared spectroscopy.

Fourier Transform Infrared spectroscopy was applied to detect in vitro cell death induced in prostate (PC-3) and breast (T47D) cancer cell lines treated with xanthohumol (XN). After incubation of the cancer cells with XN, specific spectral shifts in the infrared spectra arising from selected cellular components were identified that reflected biochemical changes characteristic for apoptosis and necrosis. Detailed analysis of specific absorbance intensity ratios revealed the compositional changes in the secondary structure of proteins and membrane lipids. In this study, for the first time we examined the changes in these molecular components and linked them to deduce the involvement of molecular mechanisms in the XN-induced death of the selected cancer cells. We showed that XN concentration-dependent changes were attributed to phospholipid ester carbonyl groups, especially in the case of T47D cells, suggesting that XN acts as an inhibitor of cell proliferation. Additionally, we observed distinct changes in the region assigned to the absorption of DNA, which were correlated with a specific marker of cell death and dependent on the XN dose and the type of cancer cells. The microscopic observation and flow cytometry analysis revealed that the decrease in cancer cell viability was mainly related to the induction of necrotic cell death. Moreover, the T47D cells were slightly more sensitive to XN than the PC-3 cells. Considering the results obtained, it can be assumed that apoptosis and necrosis induced by XN may contribute to the anti-proliferative and cytotoxic properties of this flavonoid against cancer cell lines PC-3 and T47D.

The O1/H3-preferred 1:1 H-bonding and the electron-cloud migration induced by H-bonding or non-specific interactions: A systematic study on the interactions between dimethyl phthalate and 1-, 2- or 3-alkanol (C2-C6)

H-bonding and non-specific interactions between dimethyl phthalate (DMP) and different human body substances were considered to be mainly responsible for various health dysfunctions. However, the manner of H-bonding and the adaptability of the structure of DMP that may underpin the H-bonding/non-specific interactions have been difficult to assess and remain elusive. In this study, we set out to gain an insight into the subjects above through a systematic investigation on the interactions between DMP and 1-, 2- or 3-alkanol (C2 - C6). We calculated the H-bond distances, the CO and CO bond lengths and other selected structural essentials at B3LYP 6-311G(d) level. We recorded the infrared spectra Band I and Band II of CO of DMP when dissolving DMP into 11 different alkanol/n-Hexane binary solvent systems. We created and fit the equations to delineate the dependence of the absorption intensity ratio of Band II to Band I (AII/AI) on the volume-ratio of the alkanol component (x). Based on the equations, we obtained the percent of the major alkanol associates (−p), the binding constant of the 1:1 and 1:2 DMP-alkanol complexes (K1 and K2) and the ratio of the molar absorptivity of H-bonded CO to the molar absorptivity of non-bonded CO (εhb/εns). The −p, K1, K2 and εhb/εns values confirmed the calculated results. It can be concluded that H-bonds mainly form the 1:1 complexes at O1 and H3, leading to species O5-H1⋯O1 = C1 for 3-alkanols and species O5-H1⋯O1 = C1 and Ph-H3⋯O5 for 2-alkanols. The differences of the affinity of H-bonding were mainly attributed to the steric hindrance and to a lesser extent to the hydrophobic interactions and the multi-H-bond cooperativity. The electron-cloud of the DMP molecule was supposed to migrate mainly in the E1 or E4 mode to adapt to the H-bonding or non-specific interactions, respectively.

Non-enzymatic sensing of dopamine by localized surface plasmon resonance using carbon dots-functionalized gold nanoparticles

A highly selective, sensitive, and rapid colorimetric sensor for the determination of dopamine (DA) was developed using the color change of S-doped carbon dots functionalized gold nanoparticles (S-CDs@Au NPs). The base of the method is the formation of a complex between the amine groups of dopamine with carboxylic groups of S-CDs@Au NPs followed by their aggregation with Fe3+ ions which acts as the linkers causing a red shift from 520 to 670 nm in the localized surface plasmon peak of S-CDs@Au NPs. The ratio of absorbance intensity at 670 nm to 520 nm was monitored as the analytical signal for determination of dopamine. The parameters affecting the analytical signal including reaction time, solution pH, the concentration of Au NPs and concentration of Fe3+ were optimized. At optimized conditions, the calibration curve was linear in the concentration range of 0.81–16.80 μM of dopamine. The detection and quantification limits were 0.23 μM and 0.77 μM, respectively. The intra-day and inter-day relative standard deviation (RSDs) at 5.0 μM of DA were 3.9% and 5.6%, respectively (n = 5). The applicability of the method for determination of DA in dopamine ampoule, urine and serum human samples was investigated.

Is it safe to irradiate historic silk textile against fungi?

The finding of heavily damaged historic silks prompted this study to answer the title question on possible unwanted effects of fungal decontamination by gamma-irradiation. Although silk fiber constitutes of relatively stable protein fibroin heritage silk textiles need protection from biodegradation. Low-dose (0.5−2 kGy) gamma-irradiation is already recognized as a fast, temperature independent method of insect eradication. For fungal decontamination, somewhat higher absorbed doses are needed. Since possible unwanted side effects to already damaged material must be excluded, model samples were prepared by aging contemporary silk. Some of the unaged and aged samples were irradiated to 6 kGy and other to a much higher dose of 120 kGy to identify radiation-specific damage, if any. In order to achieve detectable damage selected irradiated and non-irradiated model samples were subjected to further artificial aging. None of the assessment methods used (ATR-FTIR, SEM thermal analysis) revealed any radiation-specific change. Provided that the fibroin conformations are identified and analyzed separately, FTIR is the method of choice for monitoring the effects caused by any treatment of silk. An increase in the amide I/II absorption intensity ratio is a sensitive though ambiguous indicator of silk degradation. Transformation of more stable beta-sheet to alpha/random coil fibroin conformation is a definite proof of degradation. It occurred exclusively on artificial aging of model silks and was accompanied by pronounced morphology changes confirming the role of conformation on silk stability. In non-treated historic silks the fraction of more stable beta-sheet conformation was unexpectedly high as was the iron content that likely protected silk structure. Since irradiation produced insignificant and likely partially reversible effects radiation treatment of silk textile is deemed safe beyond the absorbed dose proposed as an upper limit for fungal decontamination, 8 ± 2 kGy.

A Highly Sensitive and Selective Colorimetric Hg2+ Ion Probe Using Gold Nanoparticles Functionalized with Polyethyleneimine.

A highly sensitive and selective colorimetric assay for the detection of Hg2+ ions was developed using gold nanoparticles (AuNPs) conjugated with polyethyleneimine (PEI). The Hg2+ ion coordinates with PEI, decreasing the interparticle distance and inducing aggregation. Time-of-flight secondary ion mass spectrometry showed that the Hg2+ ion was bound to the nitrogen atoms of the PEI in a bidentate manner (N–Hg2+–N), which resulted in a significant color change from light red to violet due to aggregation. Using this PEI-AuNP probe, determination of Hg2+ ion can be achieved by the naked eye and spectrophotometric methods. Pronounced color change of the PEI-AuNPs in the presence of Hg2+ was optimized at pH 7.0, 50°C, and 300 mM·NaCl concentration. The absorption intensity ratio (A700/A514) was correlated with the Hg2+ concentration in the linear range of 0.003–5.0 μM. The limits of detection were measured to be 1.72, 1.80, 2.00, and 1.95 nM for tap water, pond water, tuna fish, and bovine serum, respectively. Owing to its facile and sensitive nature, this assay method for Hg2+ ions can be applied to the analysis of water and biological samples.

Effect of Ultra-fine Pulverization on the Properties of Tomato Peel Residues

To investigate the effect of ultra-fine pulverization technology on properties of tomato peel residues, a series of analytical techniques including laser particle size analysis, scanning electron microscopy, X-ray energy-dispersive spectroscopy, infrared spectroscopy, zeta potential and antioxidant activity assay have been applied to comparative analysis of particle size distribution, specific surface area, microstructure, absorption intensity ratio of chemical functional groups, stability and solubility of dispersion solution, in vitro antioxidative activity and other biological activities of the powder samples prepared from tomato peel residues subjected to ultra-fine pulverization. The results showed that the structure and cell wall of the ultra-fine powder (300 mesh powder) prepared from tomato peel residues revealed more serious damage when compared with the coarse powder (80 mesh powder), the smaller diameter of the 300 mesh powder was reduced by 10 times, but the specific surface area of the 300 mesh powder was increased by four times when compared with the 80 mesh powder; meanwhile, the relative content of each functional group with high absorption intensity was higher than that in 80 mesh powder prepared from tomato peel residues; in addition, the dispersion stability of 300 mesh powder from tomato peel residues was better than that of 80 mesh powder in aqueous solution. Moreover, in vitro antioxidant activity of ultra-fine power was significantly higher than that of the coarse power. This study may help for tomato in deep processing.

The interaction strengths and spectroscopy parameters of the C2H2∙∙∙HX and HCN∙∙∙HX complexes (X = F, Cl, CN, and CCH) and related ternary systems valued by fluxes of charge densities: QTAIM, CCFO, and NBO calculations.

This theoretical work exhibits a new systematic study of structural parameters, electronic properties, infrared vibration modes, and molecular topography of hydrogen complexes, namely linear-type HCN⋯HX and T-type C2H2⋯HX (X = F, Cl, CN, and CCH). Ideally, the knowledge of the ternary systems of C2H2⋯HCN⋯HF and HCN⋯HCN⋯HF whose subparts integrate the linear and T-shaped complexes were used to give support in this current research. By means of computational calculations carried out in both levels B3LYP and MP2, the variations of the HX bond lengths are clearly overestimated in the HCN⋯HX linear complexes. In agreement with the analyses of the electrostatic potentials, the higher intermolecular energies of these complexes agree with the larger red-shifts in the stretch frequencies in HX. Also, the QTAIM descriptors and NBO calculations were used to inspect the interaction strength as well as to confirm the π cloud as a proton accepting center. By taking into account the absorption intensity ratio as a standard parameter to predict the interaction strength and intermolecular characterization, the formalism of the charge-charge flux-overlap modified (CCFO) was applied.