Benzene-carbon Tetrachloride Research Articles

Infrared spectroscopy of quasi-ideal binary liquid mixtures: The challenges of conventional chemometric regression

We have recorded ATR-IR spectra of binary mixtures in the (quasi-)ideal systems Benzene-Toluene, Benzene-Carbon tetrachloride and Benzene-Cyclohexane and performed classical least squares, inverse least squares and principal component regression on the resulting spectra. In contrast to the general expectation, the spectra of ideal mixtures follow only roughly Beer’s approximation, in particular stronger bands show shifts and increased intensities for intermediary compositions since the polarization of matter by light cannot be neglected. As a consequence, these conventional regression techniques lead to principle and unavoidable errors, even though some of the classical regression techniques are assumed to be able to cope with nonlinearities. In particular in the system Benzene-Carbon tetrachloride large errors result and the relative average error of the volume fraction determination is about 10 % for all three methods. Especially remarkable is that the multivariate regression methods do not perform better than the classical univariate calibration if for the latter a peak due to an oscillator with comparably low oscillator strength is selected, since for such bands polarization effects are weak and Beer’s approximation holds comparably well.

Beyond Beer's Law: Quasi-Ideal Binary Liquid Mixtures.

We have recorded attenuated total reflection infrared spectra of binary mixtures in the (quasi-)ideal systems benzene-toluene, benzene-carbon tetrachloride, and benzene-cyclohexane. We used two-dimensional correlation spectroscopy, principal component analysis, and multivariate curve resolution to analyze the data. The 2D correlation proves nonlinearities, also in spectral ranges with no obvious deviations from Beer's approximation. The number of principal components is much higher than two and multivariate curve resolution carried out under the assumption of the presence of a third component, results in spectra which only show bands of the original components. The results negate the presence of third components, since any complex should have lower symmetry than the individual molecules and thus more and/or different infrared-active bands in the spectra. Based on Lorentz-Lorenz theory and literature values of the optical constants, we show that the nonlinearities and additional principal components are consequences of local field effects and the polarization of matter by light. Lorentz-Lorenz theory is, however, not able to explain, for example, the different blueshifts of the strong A2u band of benzene in the three mixtures. Obviously, infrared spectroscopy is sensitive to the short-range order around the molecules, which changes with content, their shapes, and their anisotropy.

Fabrication of an efficient structured packing for hard vacuum distillation processes and calibration by Carbon tetrachloride-Benzene mixture

In vacuum distillation processes, pressure drop per unit of theoretical plate (Δp) is an important parameter because overall pressure drop of distillation column must be lower than one atmosphere (0<ΔP<1 atm.). Besides, in hard distillation processes having small relative volatility coefficient (1<αi<1.1), minimum number of theoretical plates per unit length (nmin) is another important parameter as total height of distillation column cannot exceed the maximum of technologically attainable height. Moreover, by increasing total height of the column its thermal control will be extremely hard. In this work, an efficient structured packing for hard vacuum distillation processes has been fabricated and also calibrated using the binary mixture of Carbon tetrachloride-Benzene, with very low relative volatility coefficient (1.128<αi<1.142). In hard vacuum distillation processes both parameters, Δp and nmin, are important. Therefore, the effects of three main variables including reflux volumetric flow rate, the number of distributors within the packed-bed and average height of each element of the structured packing on these parameters have been studied. The best amounts of Δp and nmin found to be 1.394 mmHg/tray and 14.2175 tray/m respectively. This vividly indicates that the newly introduced structured packing is appropriate for hard vacuum distillation processes.

Charge Transfer Complex Role in the Formation of Chlorobenzene in the γ‐Irradiated Carbon Tetrachloride‐Benzene System

AbstractThe formation of carbon tetrachloride‐benzene charge transfer complex was confirmed by UV and NMR spectrometric studies. A change in UV spectrum of benzene is observed upon addition of carbon tetrachloride. Whereas the appearance of new bands supports the formation of charge transfer complex. NMR study shows that, chemical shift of benzene pmr signal depends on the CCl4‐C6H6 molar ratio. This observation is another criterion for the formation of benzene‐carbon tetrachloride charge transfer complex. Job's Continuous Variation method indicates that a 2:1 CCl4‐C6H6 charge transfer complex (2:1 CTC) is formed. The association constants (K2:1) of (2:1 CTC) was found to be 0.0197 M−2. The maximum concentration of (2:1 CTC) was found to be in samples with 2:1 CCl4‐C6H6 molar ratio (33% benzene mole). On the other hand the maximum yield of chlorobenzene was obtained, also, upon radiolysis of CCl4‐C6H6 samples at a 2:1 molar ratio (33% benzene mole). Therefore, it could be concluded that (2:1 CTC) participates in the formation of chlorobenzene upon radiolysis of the benzene‐carbon tetrachloride system. This conclusion was supported by the dependence of the chlorobenzene yield of a γ‐irradiated carbon tetrachloride‐benzene system (2:1 molar ratio) on irradiation time according to a third order kinetic equation with a very good linearity (R2 = 0.9977). Accordingly, the rate constant for the chlorobenzene formation under this condition was found to be ≈ 5.5 × 10−7 L2.mol−2.h−1. We propose a radiation chemical mechanism in which the 2:1 CTC plays a role in the formation of chlorobenzene.

Polarization coherent anti‐stokes Raman scattering using noisy light

AbstractSeveral polarization studies on the noisy light version of coherent anti‐Stokes Raman scattering (CARS) exist in the literature. However, the full advantages of polarization CARS (P‐CARS), which are so useful in conventional and short‐pulse CARS methods, have not yet been exploited in the noisy light version. This work presents experimental realization of fully functional P‐CARS using noisy light. Several examples demonstrate the advantages brought by P‐CARS. This includes the ‘classic’ example of benzene in carbon tetrachloride. Also presented are the carbon–carbon double bond stretches in acrylonitrile and 1‐hexene. An interesting, and not fully understood, detection polarization angle dependence is discussed. Applications to an m‐xylene/benzene mixture and an alkaline solution of the amino acid phenylalanine are presented. Copyright © 2006 John Wiley &amp; Sons, Ltd.

Quantitative Determination of 1Σg+ and 1Δg Singlet Oxygen in Solvents of Very Different Polarity. General Energy Gap Law for Rate Constants of Electronic Energy Transfer to and from O2 in the Absence of Charge Transfer Interactions

The quenching of excited triplet states of sufficient energy by O2 leads to O2(1sigma(g)+) and O2(1delta(g)) singlet oxygen and O2(3sigma(g)-) ground-state oxygen as well. The present work investigates the question whether in the absence of charge transfer (CT) interactions between triplet sensitizer and O2 the rate constants of formation of the three different O2 product states follow a generally valid energy gap law. For that purpose, lifetimes of the upper excited O2(1sigma(g)+) have been determined in a mixture of 7 vol % benzene in carbon tetrachloride, in chloroform, and in perdeuterated acetonitrile. They amount to 1.86, 1.40, and 0.58 ns, respectively. Furthermore, rate constants of O2(1sigma(g)+), O2(1delta(g)), and O2(3sigma(g)-) formation have been measured in these three solvents for five pi pi* triplet sensitizers with negligible CT interactions. The rate constants are independent of solvent polarity. After normalization for the multiplicity of the respective O2 product state, the rate constants follow a common dependence on the excess energies of the respective product channels. This empirical energy gap relation describes also quantitatively the rate constants of quenching of O2(1delta(g)) by 28 carotenoids. Therefore, it represents in the absence of CT interactions a generally valid energy gap law for the rate constants of electronic energy transfer to and from O2.

Ultrafast Dynamics of Solute-Solvent Complexation Observed at Thermal Equilibrium in Real Time

In general, the formation and dissociation of solute-solvent complexes have been too rapid to measure without disturbing the thermal equilibrium. We were able to do so with the use of two-dimensional infrared vibrational echo spectroscopy, an ultrafast vibrational analog of two-dimensional nuclear magnetic resonance spectroscopy. The equilibrium dynamics of phenol complexation to benzene in a benzene-carbon tetrachloride solvent mixture were measured in real time by the appearance of off-diagonal peaks in the two-dimensional vibrational echo spectrum of the phenol hydroxyl stretch. The dissociation time constant tau(d) for the phenol-benzene complex was 8 picoseconds. Adding two electron-donating methyl groups to the benzene nearly tripled the value of tau(d) and stabilized the complex, whereas bromobenzene, with an electron-withdrawing bromo group, formed a slightly weaker complex with a slightly lower tau(d). The spectroscopic method holds promise for studying a wide variety of other fast chemical exchange processes.

The fast dynamics of benzene in the liquid phase. Part I. Optical Kerr effect experimental investigation

Femtosecond heterodyne detected optical Kerr effect experiments are performed on liquid benzene in a wide temperature range. Besides the diffusive orientational relaxation, at short times an oscillatory behaviour is observed, superimposed to a faster quasi-exponential decay. The spectral densities obtained by Fourier transform are characterised by a broad band in the region 0–150 cm−1, and their profiles show a marked temperature dependence. Similar behaviour is observed in a 1:6 molar solution of benzene in carbon tetrachloride. The experimental observations can be interpreted by assuming that the basic microscopic system, able to account for the main dynamical properties of the liquid at short times, consists of a benzene molecule librating and oscillating in a “ solvent” cage; consequently, the width of the observed intermolecular vibrational band has an essentially inhomogeneous origin. With the assumption of a bi-modal structure of the frequency distribution, a Kubo treatment is able to reproduce the main features of the experimental spectra at different temperatures. In particular, it is confirmed that the peculiar low frequency shape of the spectrum, corresponding to the fast quasi-exponential decay observed in the time-domain experiments, can be attributed to the motional narrowing effect. The value of the Kubo correlation time τc thus estimated ranges between 0.70 and 0.25 ps on going from temperatures close to the benzene melting point to near the boiling temperature.

General aspects concerning the reference techniques and the additional shielding for the association of 1,3,5-trinitrobenzene with benzene

The interaction of 1,3,5-trinitrobenzene (TNB) with benzene in carbon tetrachloride has been studied using 1H-NMR spectroscopy. The chemical shifts of TNB were measured relative to the internal and dispersed water phase (DP) references. In additition, the chemical shifts of the internal cyclohexane reference were measured relative to DP. The additional shielding on the acceptor, complex and the internal reference are evaluated and discussed. The concept of additional unspecific shielding (AUS) as well as the reliability of both referencing techniques for the present system are studied.

Vapor heat capacity of binary and ternary systems

Abstract The isobaric vapor heat capacities of five binary systems: ethanol-butanone, ethanol-benzene, ethanol-ethyl acetate, butanone-benzene and butanone-ethyl acetate and two ternary systems: ethanol-butanone-benzene and ethanol-butanone-ethyl acetate, with respect to compositions are determined at ca. 404.6 K and atmospheric pressure by using a constant-flow calorimeter. The accuracy of the calorimeter was checked by measuring the heat capacity of benzene and the benzene-carbon tetrachloride binary system for comparison with the literature data. The experiment error is less than 0.7%. The different changes of the vapor heat capacities with the compositions were discussed under the consideration of the different molecular interactions. Two well-known generalized equations of state were also selected for the estimation of the vapor heat capacities.

The vapor heat capacities of acetone-chloroform, benzene-carbon tetrachloride and benzene-ethanol binary mixtures

The vapor heat capacities of acetone-chloroform, benzene-carbon tetrachloride and benzene-ethanol binary mixtures as a function of temperature and composition have been measured under atmospheric pressure in a multicomponent vapor flow calorimeter. It was found that the heat capacities of benzene-carbon tetrachloride vapors display ideal behavior, while those of acetone-chloroform vapors demonstrate positive deviation and those of benzene-ethanol vapors, negative deviation from the ideal linear additive values. These phenomena are explained and discussed.

A new flow calorimeter for the determination of the isobaric heat capacity of vapors

A new flow calorimeter has been constructed to determine the isobaric heat capacity of vapors, especially multicomponent vapors. The calorimeter is capable of operation up to 673 K and 20 MPa. A novel design encloses the innermost part of the calorimeter within a double set of thick-wall, aluminum shields, replacing the traditional constant temperature bath, to minimize heat loss and precisely control the calorimeter temperature. An upper copper block within the outer shield is used to preheat the fluid while a lower copper block within the inner shield further heats the fluid to the operating temperature. Such a structure and temperature-controlling arrangement allow easy component replacement and operation. The apparatus was tested by determining the heat capacity of benzene and the benzene-carbon tetrachloride binary system at atmospheric pressure with an experimental error of less than 0.7%. Results for the two binary systems benzene-chloroform and benzene-acetone at 101.3 kPa and about 515.0 K are also given.

Experimental determination of the isobaric specific heat capacities of multicomponent vapors up to temperatures of 600 K

A new flow calorimeter has been constructed for the determination of the isobaric specific heat capacities of multicomponent vapors. It can yield reliable values over a wide temperature range with deviations of less than 1.0%. Using this apparatus, the isobaric specific heat capacities of benzene-cyclohexane, benzene-carbon tetrachloride and ethanol-carbon tetrachloride vapor mixtures have been determined under atmospheric pressure and up to 600 K. For polar mixtures, a slightly negative excess heat capacity was found, and this is explained.

The Ham bands revisited: spectroscopy and photophysics of the benzene-carbon tetrachloride complex

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Ham bands revisited: spectroscopy and photophysics of the benzene-carbon tetrachloride complexAlbert J. Gotch, Aaron W. Garrett, and Timothy S. ZwierCite this: J. Phys. Chem. 1991, 95, 24, 9699–9707Publication Date (Print):November 1, 1991Publication History Published online1 May 2002Published inissue 1 November 1991https://doi.org/10.1021/j100177a020RIGHTS & PERMISSIONSArticle Views74Altmetric-Citations20LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alerts

Two-color 2 + 2 photon resonance-enhanced ionization of benzene-carbon tetrachloride binary clusters

Binary clusters produced from benzene—carbon tetrachloride (9:1) mixtures are ionized by two-color (UV-VIS) excitation through the resonance pumping of the benzene S 2 state or the charge-transfer state of the benzene—carbon tetrachloride complex. The observed ions are C 6H + 7, (C 6H 6) n C 6H 6Cl +, C 7H 5H 7Cl +, and C 7H 5Cl + 2 in addition to (C 6H 6) + n ( n = 1,2,3,..). Resonance two-photon excitation at 210 nm, in which the total energy (11.8 eV) is greater than the ionization potential of benzene (9.25 eV), generates neutral intermediate states with lifetimes of 250–320 ns. The visible laser ionization with a delay from the first two-photon excitation appeared to be also a two-photon resonance process, the first step of which is probably the T ← T transition of benzene. The main reason for maintaining neutral states, in spite of the absorption of high energy, is attributed to the double excitation of C 6H 6 and CCl 4 molecules and the subsequent dissociation of electronically excited CCl 4 in the binary clusters. Condensation reactions of the component molecules in a benzene dimer ion unit and in benzene—carbon tetrachloride binary ions are found to be highly efficient for this system.

Raman‐induced kerr effect spectroscopy of solutions

AbstractRaman‐induced Kerr effect spectroscopy (RIKES) as a tool for the investigation of species in solution is presented. RIKES has proved to be a particularly useful probe for Raman modes of molecules in solution because control of the polarizations of the interacting laser fields allows non‐resonant solvent contributions to the background to be minimized. New techniques to subtract laser power fluctuations from the signal have further increased the sensitivity of RIKES. Spectra of carbon tetrachloride, benzene and the hydroxide ion are presented to show the utility of RIKES for investigating solutions. The ability to decrease background noise by controlling the polarization of the pump laser was demonstrated by studying the 459 cm−1 carbon tetrachloride resonance. Concentration studies on benzene in carbon tetrachloride showed a narrowing of the 992 cm−1 mode of benzene as its concentration was decreased. The sensitivity of the technique is demonstrated with spectra recorded on 0.01 M benzene in carbon tetrachloride. The 3620 cm−1 OH− resonance is presented for a 10 M solution of NaOH in water. A nearby water resonance makes the OH− mode difficult to see at lower concentrations. Polarization tuning was not able to improve the RIKES sensitivity in this case.

ChemInform Abstract: Photochemistry of (μ‐Tetraphenylporphyrinato)bis[dicarbonylrhodium(I)] in Benzene‐Carbon Tetrachloride Mixture.

Chemischer InformationsdienstVolume 17, Issue 14 Organoelement Compounds ChemInform Abstract: Photochemistry of (μ-Tetraphenylporphyrinato)bis[dicarbonylrhodium(I)] in Benzene-Carbon Tetrachloride Mixture. M. HOSHINO, M. HOSHINOSearch for more papers by this authorK. YASUFUKU, K. YASUFUKUSearch for more papers by this author M. HOSHINO, M. HOSHINOSearch for more papers by this authorK. YASUFUKU, K. YASUFUKUSearch for more papers by this author First published: April 8, 1986 https://doi.org/10.1002/chin.198614303AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URLThe site is currently under maintenance and this functionality is not available right now. Please try later. Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume17, Issue14April 8, 1986 RelatedInformation

Polarization sensitive resonance CARS spectroscopy

Polarization CARS spectroscopy is known to considerably enhance the CARS sensitivity of weak Raman resonances by background suppression in transparent media. Experimental control of the spectral line shape through polarization enables the determination of molecular parameters by line shape analysis. We demonstrate that polarization CARS can also be applied to absorbing substances, i.e., under electronic resonance conditions, for the case of pseudoisocyanine chloride. The spectra, recorded in the multiplex mode, are interpreted theoretically and the parameters involved in the third order susceptibility are determined from experiment. Multiplex performance of polarization CARS spectroscopy is also demonstrated for solutions of pyridine in water and benzene in carbon tetrachloride as transparent systems.

Photochemistry of (.mu.-tetraphenylporphyrinato)bis[dicarbonylrhodium(I)] in benzene-carbon tetrachloride mixture. Formation of chloro(tetraphenylporphyrinato)carbonylrhodium(III)

Photochemistry of (.mu.-tetraphenylporphyrinato)bis[dicarbonylrhodium(I)] in benzene-carbon tetrachloride mixture. Formation of chloro(tetraphenylporphyrinato)carbonylrhodium(III)

Molecular reorientation of benzene in carbon tetrachloride, tetramethylsilane and neopentane solutions

The depolarized Rayleigh scattering of benzene in CCl4, C(CH3)4 and Si(CH3)4 solutions has been investigated. Despite the similar molecular sizes and polarizabilities of the solvents, the wing spectra in dilute solutions are observed to be very different. Orientational memory functions calculated from the spectra show a pronounced oscillatory pattern in the CCl4 solutions, the pattern being much less obvious in the C(CH3)4 and Si(CH3)4 solutions. Since it is improbable that these changes are due to changes in the interaction-induced scattering, they are attributed to changes in the orientational dynamics. Following previous work on benzene, the oscillatory pattern is attributed to librational motion of the benzene molecule in the liquid. The libration persists if benzene is encaged by heavy molecules, such as CCl4, but diminishes in solutions with light molecules, such as C(CH3)4 and Si(CH3)4.