Frequency of OH in solutions of n-butanol in carbon tetrachloride: effect of dilution

It is noted that the 1 <-- 0 transition for nuOH shows a blue shift as the relative concentration of n-butanol in a CCl4-n-butanol is reduced. The magnitude of the shift decreases for the 2 <-- 0 transition and there is almost no shift for the 3 <-- 0 transition. These observations are consistent with the observed red shift [Y. Mizugai, F. Takimoto, M. Katayama, Chem. Phys. Lett. 76 (1980) 615] on dilution for the 5 <-- 0 transition in n-butanol. The observations have been interpreted on the basis of formation of O-H....Cl hydrogen bond.     

Heats of dilution of polystyrenesulphonates in dioxane-water mixtures

The heats of dilution of polystyrenesulphonic acid and its sodium salt in 25, 50 and 75 wt% mixtures of dioxane and water have been measured at 25°C in the concentration range from about 0.3 to about 0.003 M in monomer units. The heat effects decrease with decreasing dielectric constant of the solvent and become negligible for the acid in about 80% dioxane and for the sodium salt in about 60% dioxane. At these two concentrations of dioxane, phase separation has been observed. The experimental results have been compared with the predictions of the cylindrical cell and infinite line charge models and a satisfactory agreement has been found.     

Pyridyl phosphates from the reaction of sodium pyridinates,dialkyl phosphite and carbon tetrachloride

A convenient method for preparing pesticidal pyridyl phosphates from the reaction of sodium halopyridinales, dialkyl phosphite and carbon tetrachloride is described. The dialkyl phosphonato anion as an intermediate in this reaction is proposed.     

Heats of pyridine intercalation with α- and γ-zirconium phosphates

Calorimetric measurements at 25°C were made to determine the thermodynamic quantities for the intercalation of pyridine with α- and γ-zirconium phosphates. These phosphates showed exothermic reactions with ΔH⁰ = ?59.3 and ?21.9 kJ mole^?1, respectively. The large difference between the depyridination temperatures for both intercalates is rediscussed with the aid of the ΔG⁰ data obtained.     

Stereochemical aspects of the reaction of dialkyl phosphates with amine in the presence of triphenylphospine and carbon tetrachloride

Activation of P-chiral dialkyl phosphates with triphenylphosphine-carbon tetrachloride involves intermediate phosphonium salt 1 which undergoes nucleophilic attack by aniline or pyridine with inversion of configuration at the chiral phosphorus atom.     

Photolysis of acetone in carbon tetrachloride

Conclusions The efficient photolysis of acetone proceeds upon the photoexcitation of the donor-acceptor complex of acetone and CCl₄ by light with 300 > < 330 nm with the formation of chloroketones and CHC1₃ as the major products. A mechanism was proposed for the photolysis of acetone in the presence of CCl₄.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2601–2603, November, 1987.     

Dynamics of dilute water in carbon tetrachloride

A dilute solution of water in a hydrophobic solvent, such as carbon tetrachloride (CCl4), presents an opportunity to study the rotational properties of water without the complicating effects of hydrogen bonds. We report here the results of theoretical, experimental, and semiempirical studies of a 0.03 mole percent solution of water in CCl4. It is shown that for this solution there are negligible water-water interactions or water-CCl4 interactions; theoretical and experimental values for proton NMR chemical shifts (deltaH) are used to confirm the minimal interactions between water and the CCl4. Calculated ab initio values and semiempirical values for oxygen-17 and deuterium quadrupole coupling constants (chi) of water/CCl4 clusters are reported. Experimental values for the 17O, 2H, and 1H NMR spin-lattice relaxation times, T1, of 0.03 mole percent water in dilute CCl4 solution at 291 K are 94+/-3 ms, 7.0+/-0.2 s, and 12.6+/-0.4 s, respectively. These T1 values for bulk water are also referenced. "Experimental" values for the quadrupole coupling constants and relaxation times are used to obtain accurate, experimental values for the rotational correlation times for two orthogonal vectors in the water molecule. The average correlation time, tauc, for the position vector of 17O (orthogonal to the plane of the molecule) in monomer water, H2(17)O, is 91 fs. The average value for the deuterium correlation time for the deuterium vector in 2H2O is 104 fs; this vector is along the OD bond. These values indicate that the motion of monomer water in CCl4 is anisotropic. At 291 K, the oxygen rotational correlation time in bulk 2H2(17)O is 2.4 ps, the deuterium rotational correlation time in the same molecule is 3.25 ps. (Ropp, J.; Lawrence, C.; Farrar, T. C.; Skinner, J. L. J. Am. Chem. Soc. 2001, 123, 8047.) These values are a factor of about 20 longer than the tauc value for dilute monomer water in CCl4.     

Detection of carbon tetrachloride associates in isooctane

The cryoscopic and radiospectroscopic data revealed that carbon tetrachloride (CCl₄) _n agglomerates (n ≥ 4) could form in cyclohexane and carbon tetrachloride itself. Additional arguments in favor of the formation of similar CCl₄ agglomerates in isooctane were presented by analyzing the available data on positron annihilation in CCl₄ solutions in isooctane.     

Self-association of carbon tetrachloride in gas and condensed phase

The paper suggests the model of carbon tetrachloride self-association in gas and condensed phases, based on comparative analysis of IR findings for carbon-, silicon-, and germanium tetrachloride, obtained at different temperatures in gas, as well as in liquid, solid state, and noble gas solutions.

     

Partial molar volumes of methoxybenzenes in carbon tetrachloride

The partial molar volumesV° for a number of methoxybenzenes in carbon tetrachloride at 25°C have been determined. Results are in reasonable aggreement withV° values calculated by the addition of group increments to a covolume factor of 11.61 cm³-mol^?1, and subtraction of fixed amounts for structural features known to involve intramolecular overcrowding.     

Rotational structure of water in a hydrophobic environment: carbon tetrachloride

Infrared spectroscopy has been used to probe the interaction between water and the hydrophobic solvent, carbon tetrachloride. At room temperature, water exists as monomers in carbon tetrachloride, presenting a system for studying the rotational properties of water free of strong hydrogen-bonding. The rotational structure suggests a very anisotropic motion consisting of essentially free rotation about the symmetry axis and highly hindered rotation about the two perpendicular axes of the asymmetric water molecule. The rotational lifetime is significantly shortened relative to gas-phase water. An upper limit of 0.93 ps is deduced from the spectrum. Interaction with carbon tetrachloride also slightly enhances the intensity of the symmetric stretch. The results are compared with results of interactions between water and the cations Li+, Na+, K+, and Cs+. It is concluded that the attractive interaction is between the oxygen of water and the electropositive carbon of carbon tetrachloride.     

Chlorination of various substrates in subcritical carbon tetrachloride

Various aliphatic hydrocarbons and the side chains of aromatic hydrocarbons were chlorinated in subcritical carbon tetrachloride. Chlorination of aromatic compounds including 1,4-disubstituted benzenes was investigated. Ketones and sulfones were stable under the employed conditions. Sulfoxides were converted into sulfides in a low to modest yields. The coupling adducts between olefins and carbon tetrachloride were obtained from the reactions of olefins.     

Temperature dependence of vibrational relaxation in carbon tetrachloride

The temperature dependence of vibrational relaxation in carbon tetrachloride has been investigated from near the melting point to near the boiling point. The method of spontaneous Brillouin scattering has been used to determine the hypersonic frequencies and velocities as functions of temperature. The dispersion in the velocities are then compared with theoretical predictions in order to investigate the character of the relaxation.     

Interpretation of light-scattering spectra in terms of particle displacements

Quasielastic light-scattering spectroscopy is regularly used to examine the dynamics of dilute solutions of diffusing mesoscopic probe particles in fluids. For probes in a simple liquid, the light-scattering spectrum is a simple exponential; the field correlation function g(1)(q,tau) of the scattering particles is related to their mean-square displacements X2 identical with [(delta x(tau))2] during tau via g(1)(q,tau) = exp(-1/2 q2X2). However, demonstrations of this expression refer only to identical Brownian particles in simple liquids and show that if the form is correct then it is also true for all tau that g(1)(q,tau) = exp(-gamma tau), a pure exponential in tau. In general, g(1)(q,tau) is not a single exponential in time. A correct general form for g(1)(q,tau) in terms of the X(2n), replacing the incorrect exp(-1/2 q2X2), is obtained. A simple experimental diagnostic determining when the field correlation function gives the mean-square displacement is identified, namely, g(1)(q,tau) only reveals X2 if g(1)(q,tau) is a single exponential in tau. Contrariwise, if g(1)(q,tau) is not a single exponential, then g(1)(q,tau) depends not only on X2 but on all higher moments X(2n). Corrections to the crude approximation g(1)(q,tau) = exp(-1/2 q2X2) closely resemble the higher spectral cumulants from a cumulant expansion of g(1)(q,tau).     

Infrared spectrum of benzene in bromine and carbon tetrachloride solutions

The benzene—bromine complex at room temperature has been re-studied by infrared with bromine in excess of benzene. Solutions of 0.225 M benzene in bromine—carbon tetrachloride mixtures were studied. Under this condition, the spectral changes of measurable benzene absorption bands were observed more clearly than previously. The out-of-plane vibrations of benzene were observed to shift to higher frequencies. The equilibrium constant was found to be 0.11 ? mole^?1. The accord with the equilibrium constant derived from benzene rich systems supports the concept of a specific interaction. A C_6V symmetry is favoured for the geometry of the complex.