自溶液中的吸附XIII.硅胶自环己烷-正脂肪醇和水-正脂肪醇中吸附TRITONX-100

测定了硅胶和活性炭自水、环己烷和正丁醇中吸附TRITON X-100的等温线,提出了TRITON X-100在硅胶-环己烷界面上形成单分子层,在硅胶-水界面上形成双分子层的吸附模型,测定了硅胶自环己烷-正脂肪醇(C2,C4,C8和C12)和水-正脂肪醇(C2和C4)混合溶剂中吸附TRITON X-100的等温线,自环己烷-正脂肪醇中的吸附时,醇的烃链越短,浓度越大,降低TRITON X-100的吸附作用越显著.自水-正脂肪醇中吸附时,正丁醇降低TRITON X-100的吸附作用比乙醇时更显著,但当TRITON X-100的浓度较低时,正丁醇(0.5mol.dm[-3])的存在却使TRITON X-100的吸附有所增加。     

Vapour pressures and heat capacity measurements on the C7–C9 secondary aliphatic alcohols

Molar enthalpies of vaporization of secondary C₇–C₉ alkanols were obtained from the temperature dependence of the vapour pressure measured by the transpiration method. The measured data sets were checked for internal consistency successfully. A large number of the primary experimental results on temperature dependences of vapour pressures of secondary alcohols have been collected from the literature and have been treated uniform in order to derive their vaporization enthalpies at the reference temperature 298.15 K. This collection, together with our experimental results, have helped to ascertain the database for branched aliphatic alcohols.     

Sorption of aliphatic alcohols from aqueous solutions by starch cryotextures

Capillary GLC was applied to study the sorption ofn-butanol,n-hexanol,n-octanol, and linalood from aqueous solutions by com starch cryotextures. The concentrations of alcohols in aqueous solutions were varied from 0.5 to 15 mmol L⁻¹. The sorption of alcohols by crytotextures formed of sols containing these alcohols and the coefficients of their. distribution depend on the initial concentration and structure of the alcohols.n-Butanol is not sorbed by the corn starch cryotextures over the range of 0.5–80 mmol L⁻¹. The sorption of other alcohols increases with increasing length of the alkyl substituent and the concentration of the alcohol. The highest sorption capacity of the cryotexture (88%) was observed forn-octanol. The sorption of linalool decreases due to the double bonds and branching in its molecules. Translated fromIzestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 734–737, April, 1999.     

Synthesis of aliphatic and aralkyl amino alcohols from 1,1,1,5-tetrachloropentane

Russian Chemical Bulletin - Starting with 1,1,1,5-tetrachloropentane, we synthesized some previously unknown aminopentanols of general formula: $$R - \begin{array}{*{20}c} {OH} \hfill \\ | \hfill...     

Selectivity of tetrahydrofuran formation from inactivated aliphatic alcohols by the bromine-silver-salt reaction

Studies of the bromine-silver carbonate reaction with aliphatic alcohols in which intramoleular δ-H competition is possible are generally quite specific. Loss of tertiary δ- hydrogen occurs preferentially from both tertiary and secondary alfphatic alcohols to yield the most highly substituted cyclic ether. For example, 2,5-dimethyl-2-octanol yields only 2,2,5-trimethyl-5-propyletrahydrofuran as the cyclic ether product; 2-methyl-2-isopentyltetrahydrofuran is not detected.     

On the adsorption of aliphatic alcohols on gold Part II

The adsorption of a wide selection of aliphatic alcohols on a polycrystalline gold electrode from 0.02 M NaF solution was studied using the tensammetric method. The thermodynamic data presented for the primary and secondary alcohols show close correlations between structure and Gibbs energy of adsorption. The standard Gibbs energy of adsorption increases with the chain length of primary alcohols by 3.5 kJ/mol for every additional C atom and by 2.7 kJ/mol in the case of secondary alcohols. The discussion of the data includes results presented previously and shows new aspects for the interpretation of the kinetic data of the anodic oxidation of these alcohols in alkaline solutions. This is supported by the tensammetric data obtained for some typical alcohols and the gold electrode in an electrolyte solution of 0.04 M KOH.     

New observations on the photopinacolization of benzophenone in aliphatic alcohols

Irradiation of benzophenone in alcohol solutions produces unsymmetrical pinacols and para-coupled products as well as benzpinacol; the product composition depends on light intensity.     

Dipole relaxation in normal aliphatic alcohols

A new mechanism of dipole relaxation and molecular motion in normal aliphatic alcohols is suggested, based on the assumption of the existence of consequent reorientations of the molecules in chains It is shown that the experimental data obtained by different methods of dielectric spectroscopy, including TDS. can be described accurately within the framework of the model.     

Liquid densities from 293 to 490 K of nine aliphatic alcohols

The results of measurements of liquid densities within the temperature range 293 to 490 K are presented for highly pure samples of n-alcohols C1 to 5, 8 and 12, and of propan-2-ol and butan-2-ol. Measurements were made by means of a magnetically controlled float which could be held in the centre of the sample with the sample cell suspended from an automatic balance. The results are considered to have an accuracy of ±0.15 kg m^?3 over this range of temperature. Some large disagreements with published data are identified. Densities at temperatures above the upper limit of the measurements can not be estimated reliably.     

Photoionization mass spectrometry of aliphatic monoterpene alcohols

Summary 1. The dissociative processes observed in the photoionization of monoterpene alcohols have been investigated. It has been established that the relative intensities of the peaks of the heavy ions, including the molecular ions, are higher on photoionization than on electron impact.2. It has been found that the mass spectra of the isomeric alcohols obtained on photoionization differ from one another to a greater degree than the electronic mass spectra.Agrophysical Scientific-Research Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 723–726, November–December, 1974.     

Ice nucleation by monolayers of aliphatic alcohols

Monolayers of aliphatic long chain alcohols (C_nH_2n+1OH) were found to induce nucleation of ice at temperatures approaching O°C in contrast to water-soluble alcohols which are efficient antifreeze agents. The corresponding fatty acids and alcohols with bulky hydrophobic groups, induce ice nucleation at temperatures lower by as much as 12°C. The freezing point induced by the amphiphilic alcohols was found to be sensitive not only to area per molecule but also to chain length and parity, reaching higher temperatures for monolayers with n odd. Grazing incidence X-ray diffraction studies performed on some of these alcohols at the air/water interface (at 5°C and at zero pressure), demonstrated the formation of crystalline two-dimensional clusters with a distorted hexagonal cell whose dimensions resemble those of hexagonal ice. The catalysis of ice nucleation by these alcohol monolayers may be rationalized in terms of the structural match between the monolayer domains and the ab layer of hexagonal ice.     

General method for the palladium-catalyzed allylation of aliphatic alcohols

A palladium catalysis-mediated approach to coupling aliphatic alcohols with allyl carbonates has been developed. The method allows for the allylation of primary, secondary, and tertiary alcohols efficiently under mild conditions. Limitations were explored as well as the asymmetric application of the chemistry. Regiochemical and olefin geometry was controlled in the coupling of unsymmetrical allylating agents. Transient allyl carbonates were observed in the coupling, which comprised the trans-carboxylation of the allyl-carbonate with the requisite alcohol.     

Mass spectra of branched long-chain aliphatic alcohols

The mass-spectral behaviour of long-chain aliphatic primary alcohols of the normal, iso-and anteiso-series have been discussed. The mass-spectral fragmentation of individual alcoholic types have been found to be structurally specific. The mass spectra of some deuterio derivatives have shown, however, the complicated nature of the fragmentation processes.