Simulation of the Raman spectra of zwitterionic glycine + nH2O (n = 1, 2, …, 5) by means of DFT calculations and comparison to the experimentally observed Raman spectra of glycine in aqueous medium

Raman spectra of an aqueous solution of glycine (Gly) have been recorded in the range of 400-2000 cm⁻¹. In aqueous solution, glycine molecules exist in their zwitterionic form, having two opposite charged poles, COO⁻ and NH₃⁺. The zwitterionic structure of glycine (ZGly) is stabilized by the hydrogen bond interaction of water (W) molecules. In the present report, we have optimized the ground state geometries of different hydrogen bonded complexes of [ZGly + (W)_n=1-5] in aqueous medium using DFT calculations at the B3LYP/6-311++G(d) level of theory. A comparative discussion on the structural details and binding energies (BEs) of each conformer has been also done. The theoretical Raman spectra were calculated corresponding to the most stable [ZGly + (W)_n=1-5] conformers. The theoretically simulated Raman spectra of each stable conformer were compared with experimentally observed Raman spectra to explore the number of water molecules needed for stabilizing the structure of ZGly. The theoretically simulated Raman spectra corresponding to the most stable conformer of [ZGly + (W)₅] having a BE of −22.8 kcal/mol, are matching nicely with the experimentally observed Raman spectra. Thus, on the basis of the above observations, we conclude that the conformer, [ZGly + (W)₅] is the most probable conformer in the aqueous medium. We also believe that in the conformer, [ZGly + (W)₅] the five water molecules are arranged around the ZGly in such a way that the effect of steric hindrance is less compared to the other conformers. The dipole-dipole interaction potential (DDP) is also calculated corresponding to the strongest hydrogen bond for each [ZGly + (W)_n=1-5] conformer.     

Raman spectra,conformational stability,structural parameters,vibrational assignment,and ab initio calculations for epifluorohydrin

The Raman spectra (3200–100 cm⁻¹) of epifluorohydrin, OCH₂CH(CH₂F), in variable solvents, as well as that of the gas have been recorded and several of the bands due to the two less stable conformers have been identified. The variable solvent studies were inconclusive on the relative conformer stabilities. The conformational energy differences and optimized geometries for all three conformers have been obtained from ab initio calculations with the 3–21G, 4–31G and 6–31G* basis sets. A normal coordinate analysis has also been performed for each conformer with a force field determined from the 3–21G basis set. Assignment of the vibrational fundamentals observed in the Raman spectra of the fluid phases is proposed based on the normal coordinate calculations. In the liquid phase, one of the conformers with a large dipole moment predominates and it appears to be the gauche-I form which is the only one found in the solid. Utilizing the three rotational constants previously reported for each conformer, along with restricted relative distances for several of the structural parameters among the conformers from ab initio calculations, r₀ structural parameters for the heavy atoms have been determined.     

Aminolysis of p-tert-butyltetrathiacalix[4]arene tetraethylacetates in cone, partial cone and 1,3-alternate conformation: synthesis of amide based receptors for oxyanions

Cone, partial cone and 1,3-alternate conformers of tetrathiacalix[4]arene tetraethylacetate were synthesized and subjected to aminolysis with alkyl amines [CH₃(CH₂)_nNH₂; n=2, 3, 5] to yield mono-, di-, tri- or tetrasubstituted p-tert-butyltetrathiacalix[4]arene amides which were characterized by detailed analysis of their NMR spectral and single crystal X-ray crystallography. It has been observed that while the 1,3-alternate and cone conformers of the tetrathiacalix[4]arene tetraethylacetate gave corresponding tetrathiacalix[4]arene tetraamides under different experimental conditions, the corresponding partial cone conformer undergoes a cascade of regioselective reactions with the same amines. Variable temperature ¹H NMR experiments allowed the determination of relative stability of different conformers within the temperature range of 298-333 K. The synthesized derivatives were evaluated as molecular extractants for cations and anions and were determined to facilitate extraction of oxyanions (CrO₄²⁻ and Cr₂O₇²⁻) from aqueous to the organic phase. The studies have a significance in the design of tetrathiacalix[n]arene based molecular receptors for innovative applications.     

Synthesis, characterization and intercalation property of layered zirconium benzylamino-N,N-dimethylphosphonate phosphate materials

Layered zirconium benzylamino-N,N-dimethylphosphonate phosphate (ZBMPA) was prepared by the reaction of zirconyl chloride with benzylamino-N,N-dimethylphosphonic acid (H₂BMPA) and phosphoric acid in the presence of hydrofluoric acid. The intercalation of n-alkylamines (n-butylamine, n-heptylamine and n-decylamine) into ZBMPA was primarily investigated at room temperature. These materials were characterized by elemental analysis, ICP, XRD, SEM, FT-IR, Raman spectra, TG and DSC. The composition of ZBMPA is Zr(HPO₄)(C₆H₅CH₂N(CH₂PO₃)₂)_0.5 · 2.0H₂O. The interlayer distance of ZBMPA, n-butylamine, n-heptylamine and n-decylamine intercalation compounds is 2.03, 2.58, 2.52 and 3.17 nm, respectively. ZBMPA and the n-alkylamine intercalation compounds are different in the morphology and vibration spectra. Thermogravimetries of all materials obtained reveal three step mass losses at temperatures of up to 1000 °C. These results indicate that n-alkylamines are intercalated into the galleries of host ZBMPA.     

New N,N-amino-diphosphonate-containing methacrylic derivatives, their syntheses and radical copolymerizations with MMA

Hydroxy-amino-diphosphonates HO-C_n-NH₂, with 2 ? n ? 11, have been successfully synthesized via the Kabachnick-Field reaction at 70 °C with high yields. These hydroxy compounds are then reacted with methacryloyl chloride to lead to novel amino-diphosphonate methacrylates MAC_nNP₂ (with 2 ? n ? 11). These highly pure methacrylate monomers were obtained with yields higher than 75%. Radical copolymerizations of MAC_nNP₂ (with 2 ? n ? 11) with MMA have been conducted and the r₁ values (related to MAC_nNP₂) are in the range of 1.1-1.3, and r₂ values (related to MMA) about 0.8; this shows that the diphosphonate groups are statistically bonded to the methacrylic backbone.     

Microwave spectrum and conformation of n-propyltrifluorosilane

The conformational properties of gaseous n-propyltrifluorosilane (CH₃CH₂CH₂SiF₃) have been investigated by microwave spectroscopy and high-level quantum chemical calculations. The microwave spectrum was investigated in the 20–62 GHz spectral range at a temperature of −78 °C. The spectra of the ground vibrational state and three vibrationally excited states of one conformer having an antiperiplanar conformation of the C–C–C–Si chain of atoms were assigned. No evidence for the existence of the synclinal (gauche) conformer was seen in the microwave spectrum. It is concluded that the synclinal form is at least 3.5 kJ/mol less stable than the antiperiplanar conformer in the gas phase. Density functional theory calculations have been performed for the system mainly to predict the effects of centrifugal distortion. The G3 quantum chemical method has been used to test the ability of this method to predict the energy difference between the synclinal and antiperiplanar conformers.     

Raman and infrared spectra, conformational stability, barriers to internal rotation, vibrational assignment, and ab initio calculations of 3-methyl-3-butenenitrile

The Raman (3500-30 cm⁻¹) spectra of liquid and solid and the infrared (3500-40 cm⁻¹) spectra of gaseous and solid 3-methyl-3-butenenitrile, CH₂C(CH₃)CH₂CN, have been recorded. Both cis and gauche conformers have been identified in the fluid phases but only the cis form remains in the solid. Variable temperature (−55 to −100 °C) studies of the infrared spectra of the sample dissolved in liquid xenon have been carried out. From these data, the enthalpy difference has been determined to be 163±16 cm⁻¹ (1.20±0.19 kJ mol⁻¹), with the cis conformer the more stable rotamer. It is estimated that there is 48±2% of the gauche conformer present at  25°C. A complete vibrational assignment is proposed for the cis conformer based on infrared band contours, relative intensities, depolarization ratios and group frequencies. Several of the fundamentals for the gauche conformer have also been identified. The vibrational assignments are supported by normal coordinate calculations utilizing ab initio force constants. Complete equilibrium geometries have been obtained for both rotamers by ab initio calculations employing the 6-31G(d), 6-311G(d,p), 6-311+G(d,p) and 6-311+G(2d,2p) basis sets at the levels of restricted Hartree-Fock (HF) and/or Møller-Plesset perturbation theory to the second order (MP2). Only with the 6-311G(2d,2p) and 6-311G(2df,2pd) basis sets with or without diffuse functions is the cis conformer predicted to be more stable than the gauche form. The potential energy terms for the conformational interchange have been obtained at the MP2(full)/6-311+G(2d,2p) level, and compared to those obtained from the experimental data. The results are discussed and compared to the corresponding quantities obtained for some similar molecules.     

Synthesis and structure of a 1,6-hexyldiamine heptaborate, [H3N(CH2)6NH3][B7O10(OH)3]

A new 1,6-hexyldiamine heptaborate, [H₃N(CH₂)₆NH₃][B₇O₁₀(OH)₃] (1), has been solvothermally synthesized and characterized by single-crystal X-ray diffraction, FTIR, elemental analysis, and thermogravimetric analysis. Compound 1 crystallizes in monoclinic system, space group P2₁/n with a=8.042(2) Å, b=20.004(4) Å, c=10.103(2) Å, and β=90.42(3)°. The anionic [B₇O₁₀(OH)₃]_n²ⁿ⁻ layers are interlinked via hydrogen bonding to form a 3D supramolecular network containing large channels, in which the templated [H₃N(CH₂)₆NH₃]²⁺ cations are located.     

Iodomethane oxidative addition and CO migratory insertion in monocarbonylphosphine complexes of the type [Rh((C6H5)COCHCO((CH2)nCH3))(CO)(PPh3)]: Steric and electronic effects

The chemical kinetics, studied by UV/Vis, IR and NMR, of the oxidative addition of iodomethane to [Rh((C₆H₅)COCHCOR)(CO)(PPh₃)], with R = (CH₂)_nCH₃, n = 1-3, consists of three consecutive reaction steps that involves isomers of two distinctly different classes of Rh^III-alkyl and two distinctly different classes of Rh^III-acyl species. Kinetic studies on the first oxidative addition step of [Rh((C₆H₅)COCHCOR)(CO)(PPh₃)] + CH₃I to form [Rh((C₆H₅)COCHCOR)(CH₃)(CO)(PPh₃)(I)] revealed a second order oxidative addition rate constant approximately 500-600 times faster than that observed for the Monsanto catalyst [Rh(CO)₂I₂]⁻. The reaction rate of the first oxidative addition step in chloroform was not influenced by the increasing alkyl chain length of the R group on the β-diketonato ligand: k₁ = 0.0333 ([Rh((C₆H₅)COCHCO(CH₂CH₃))(CO)(PPh₃)]), 0.0437 ([Rh((C₆H₅)COCHCO(CH₂CH₂CH₃))(CO)(PPh₃)]) and 0.0354 dm³ mol⁻¹ s⁻¹ ([Rh((C₆H₅)COCHCO(CH₂CH₂CH₂CH₃))(CO)(PPh₃)]). The pK_a^′ and keto-enol equilibrium constant, K_c, of the β-diketones (C₆H₅)COCH₂COR, along with apparent group electronegativities, χ_R of the R group of the β-diketones (C₆H₅)COCH₂COR, give a measurement of the electron donating character of the coordinating β-diketonato ligand: (R, pK_a^′, K_c, χ_R) = (CH₃, 8.70, 12.1, 2.34), (CH₂CH₃, 9.33, 8.2, 2.31), (CH₂CH₂CH₃, 9.23, 11.5, 2.41) and (CH₂CH₂CH₂CH₃, 9.33, 11.6, 2.22).     

The infrared and Raman spectra, ab initio calculations and spectral assignments of cyclopropylmethyl dichlorosilane (c-C3H5)SiCl2CH3

Raman spectra of cyclopropylmethyl dichlorosilane (c-C₃H₅)SiCl₂CH₃ as a liquid were recorded at 293 K and polarization data were obtained. Additional Raman spectra were recorded at various temperatures between 293 and 163 K, and intensity changes of certain bands with temperature were detected. No crystallization was ever obtained in the Raman cryostat in spite of extensive annealing. The infrared spectra have been studied as a vapour, as an amorphous solid at 78 K and as a liquid in the range 600-100 cm⁻¹. No infrared bands present in the vapour or liquid seemed to vanish upon cooling, and the sample never formed crystals on the CsI window of an infrared cryostat.The compound exists a priori in two conformers, syn and gauche, and the experimental results suggest an equilibrium in which the gauche conformer has 1.64 kJ mol⁻¹ lower enthalpy than syn in the liquid, leading to 20% syn at ambient temperature. Most of the syn bands were situated close to the corresponding gauche bands and it was difficult to obtain reliable ΔH values.B3LYP calculations with various basis sets and the CBS-QB3 and G2 and G3 models were employed, yielding the conformational enthalpy difference ΔH (syn-gauche) between 2.6 and 3.4 kJ mol⁻¹. Infrared and Raman intensities, polarization ratios and vibrational frequencies for the syn and gauche conformers were calculated. Instead of scaling the calculated wavenumbers in the harmonic approximation, calculations from B3LYP/cc-pVTZ were derived in the anharmonic approximation. In most cases these values were in good agreement with the experimental results for 38 observed modes of the gauche and 8 modes of the syn conformer with a deviation of ca. 1%.     

Theoretical study on the substitution and insertion reactions of silylenoid H2SiLiF with CH3XHn−1 (X = F, Cl, Br, O, N; n = 1, 1, 1, 2, 3)

The substitution and insertion reactions of H₂SiLiF (A) with CH₃XH_n−1 (X = F, Cl, Br, O, N; n = 1, 1, 1, 2, 3) have been studied using density functional theory. The results indicate that the substitution reactions of A with CH₃XH_n−1 proceed via two reaction paths, I and II, forming the same product H₂SiFCH₃. The insertion reactions of A with CH₃XH_n−1 form H₂SiXH_n−1CH₃. The following conclusions emerge from this work. (i) The substitution reactions of A with CH₃XH_n−1 occur in a concerted manner. The substitution barriers of A with CH₃XH_n−1 for both pathways decrease with the increase of the atomic number of the element X for the same family systems or for the same row systems. Path I is more favorable than path II. (ii) A inserts into a C-X bond via a concerted manner, and the reaction barriers increase for the same-row element X from right to left in the periodic table, whereas change very little for the systems of the same-family element X. (iii) The substitution reactions occur more readily than the insertion reactions for A with CH₃XH_n−1 systems. (iv) All substitution and insertion reactions of A with CH₃XH_n−1 are exothermic. (v) In solvents, the substitution reaction process of A with CH₃XH_n−1 is similar to that in vacuum. The barrier heights in solvents increase in the order CH₃F < CH₃Cl < CH₃Br < CH₃OH < CH₃NH₂. The solvent polarity has little effects on the substitution barriers. The calculations are in agreement with experiments.     

Formation of γ-Fe2O3 nanoparticles and vacancy ordering: An in situ X-ray powder diffraction study

The formation of maghemite, γ-Fe₂O₃ nanoparticles has been studied by in situ X-ray powder diffraction. The maghemite was formed by thermal decomposition of an amorphous precursor compound made by reacting lauric acid, CH₃(CH₂)₁₀COOH with Fe(NO₃)₃·9H₂O. It has been shown that cubic γ-Fe₂O₃ was formed directly from the amorphous precursor and that vacancy ordering starts about 45 min later at 305 °C resulting in a tripled unit cell along the c-axis. The kinetics of grain growth was found to obey a power law with growth exponents n equal to 0.136(6) and 0.103(5) at 305 and 340 °C, respectively. Particles with average sizes of 12 and 13 nm were obtained in 86 and 76 min at 305 and 340 °C, respectively. The structure of cubic and vacancy ordered phases of γ-Fe₂O₃ was studied at 305 °C by Rietveld refinements.     

Infrared and Raman spectra, conformational stability and vibrational assignment of 1-chloro-1-silacyclopentane

Infrared and Raman spectra (3500-60 cm⁻¹) of gas and/or liquid and solid 1-chloro-1-silacyclopentane (c-C₄H₈SiClH) have been recorded and the vibrational data indicate the presence of a single conformer with no symmetry which is consistent with the twisted form. Ab initio calculations with a variety of basis sets up to MP2(full)/aug-cc-pVTZ predict the envelope-axial and envelope-equatorial conformers are saddle points with nearly the same energies but much lower in energy than the planar conformer. Density functional theory calculations by the B3LYP method predicts slightly lower energies for the two envelope forms and considerably lower for the planar form. By utilizing the MP2(full)/6-31G(d) calculations the force constants, frequencies, infrared intensities, band contours, Raman activities, and depolarization values have been obtained to support the vibrational assignment. Estimated r₀ structural parameters have been obtained from adjusted MP2(full)/6-311 + G(d, p) calculations. These experimental and theoretical results are compared to the corresponding quantities of some other five-membered rings.     

Study of the electric dipole moments of the (C2H5)n PX3−n and P{EIVB (CH3)3}3 compounds (X = Cl,Br, I; EIVB = C,Si, Sn; n = 0, 1, 2, 3)

The dipole moments of the (C₂H₅)_nPX_3?n (X = Cl, Br, I; n = 0, 1, 2, 3) and P{E^IVB(CH₃)₃}₃ compounds (E^IVB = C, Si, Sn) have been determined by dielectric measurements in benzene at 25°C by Higasi's method. The results are interpreted in terms of an additive vector model from bond moment calculations and a maximum phosphorus lone pair contribution of 1.75 D as calculated for P(C₂H₅)₃. The high dipole moment of the mixed PA₂B-type compounds in comparison with PA₃ moments is mainly ascribed to a loss of C_3v symmetry, characterized by a quite asymmetric orientation of the phosphorus lone pair with respect to the phosphorus bonding orbitals.     

Synthesis and characterization of tri-block fluorinated-n-alkanes

A series of triblock semifluorinated n-alkanes of general formula F(CF₂)_n(CH₂)_m(CF₂)_nF (n = 6, 8 and m = 4, 6, 8) have been synthesized and characterized. The synthesis of triblock compounds was performed in two different ways according to the length of the hydrogenated moiety. Coupling of two molecules of β-(perfluoro-n-alkyl)ethyl iodides leads to the triblock materials F(CF₂)₆(CH₂)₄(CF₂)₆F and F(CF₂)₈(CH₂)₄(CF₂)₈F. The synthesis of compounds with larger hydrogenated part is accomplished in two steps by the addition of perfluoro-n-alkyl iodide F(CF₂)_nI to 1,5-hexadiene and 1,7-octadiene, respectively to give the diiodo-adducts which are subsequently deiodinated to the final triblock products F(CF₂)₆(CH₂)₆(CF₂)₆F, F(CF₂)₆(CH₂)₈(CF₂)₆F, F(CF₂)₈(CH₂)₆(CF₂)₈F and F(CF₂)₈(CH₂)₈(CF₂)₈F. The obtained triblock semifluorinated n-alkanes are characterized by low surface free energies with good lubricant properties usable as additives in ski-wax formulations.     

Theoretical investigations on structure, electrostatics potentials and vibrational frequencies of Li+ - CH3- O- (CH2- CH2- O)n- CH3 (n=3-7) conformers

Electronic structure, charge distributions and vibrational characteristics of CH₃ O(CH₂ CH₂ O) _n CH₃ (n=3-7) have been derived using the ab initio Hartree Fock and density functional calculations. For tri- to hexaglymes the lowest energy conformers have trans- conformation around the C-C and C-O bonds of the backbone. For heptaglyme (n=7 in the series), however, gauche-conformation around the C-C bonds renders more stability to the conformer and turns out to be 10.1 kJ mol ⁻¹ lower in energy relative to the conformer having trans-orientation around the C-C and C-O bonds. The molecular electrostatic potential topographical investigations reveal deeper minima for the ether oxygen in conformers having the gauche conformation around the C-C bonds over those for the trans- conformers. A change from trans- to gauche-conformation around the C-C bonds of the lowest energy conformer of heptaglyme engenders a triplet of intense bands ∼1,150 cm ⁻¹ in the vibrational spectra. Theoretical calculations predict that Li ⁺ binds strongly to the heptaglyme conformer in the above series. The frequency shifts in the vibrational spectra of CH₃O(CH₂CH₂O) _n CH₃- Li⁺ (n=3-7) conformers have been discussed     

Novel generation ponytails in fluorous chemistry: Syntheses of primary, secondary, and tertiary (nonafluoro-tert-butyloxy)ethyl amines

(Nonafluoro-tert-butyloxy)ethyl tosylate 4 was prepared in 65% yield from nonafluoro-tert-butanol 1 using commercially available reagents. Further reaction of 4 with HNR¹R² (R¹ = R² = H, CH₃; R¹ = H, R² = CH₃, (CH₂)₃C₈F₁₇, CH₂CH₂OC(CF₃)₃) affords the appropriate (CF₃)₃COCH₂CH₂NR¹R² amines in 20-69% yields. Improved overall yields of [(CF₃)₃COCH₂CH₂]_3−nNR_n to 1 were obtained by the reaction of (CF₃)₃CONa 2 and (XCH₂CH₂)_3−nNR_n (X = Cl, n = 0, 1, 2, R = CH₃; X = CH₃SO₂O, n = 1, R = CH₃SO₂) nitrogen mustards and a similar reactive β-substituted ethyl amine. The title amines are mobile colorless liquids and volatile with steam. The bulky fluorous ponytail (CF₃)₃CO(CH₂)₂ displays high acidic stability and increases fluorous character almost as much as the classical straight-chain C₈F₁₇(CH₂)₃ ponytail.     

Synthesis,spectral characterization,electrochemical properties and antimicrobial screening of sulfur containing acylferrocenes

Several known and eight new sulfur containing acylferrocenes of the general formula FcCO(CH₂)_nSR (where Fc = ferrocenyl, n = 1 or 2 and R = alkyl, 4-bromobenzyl or 2,6-dichlorobenzyl group) were synthesized in order to test their in vitro antimicrobial activity against 11 bacterial and three fungal/yeast strains. It has been shown that only four of the 14 ketones are completely inactive at the tested dose, while the activities of the other ones were noteworthy. All new compounds were well characterized by IR and NMR spectral data, and their electrochemical properties were investigated by cyclic voltammetry. The X-ray crystal structures of two representative ketones are also presented.     

Experimental and theoretical study of N-(2-hydroxyethyl)morpholine betaine

N-(2-hydroxyethyl)morpholine betaine (HEMB) has been characterized by a single crystal X-ray analysis, FTIR spectroscopy and DFT calculations. The crystals are monoclinic, space group P2₁/c with a=10.273(2), b=9.360(2), c=9.447(2) Å and β=104.72(3)Å. Two molecules of HEMB form a centrosymmetric dimer (X2) connected by a pair of hydrogen bonds between the CH₂CH₂OH and COO⁻ groups, with the O?O distance of 2.672(2) Å. The morpholine ring adopts a chair conformation with the CH₂CH₂OH group in the axial and the CH₂COO⁻ group in the equatorial position. The structures of the dimer, B2, and two monomers, B1a and B1b, have been optimized by the B3LYP approach using the 6-31G(d,p) basis set. The computed structure of B2, agrees well with the experimental X2. From two stable monomeric conformers the more favored is B1a, with the intramolecular hydrogen bond with the O-H?O distance of 2.566 Å. The effects of hydrogen bonding and electrostatic interactions on the conformation of the molecules investigated have been discussed. The FTIR spectrum shows a broad absorption in the 3300-2600 cm⁻¹ region, typical of moderate O-H?O hydrogen bonds.     

Synthesis of novel lipophilic and/or fluorophilic ethers of perfluoro-tert-butyl alcohol, perfluoropinacol and hexafluoroacetone hydrate via a Mitsunobu reaction: Typical cases of ideal product separation

Fluorophilic ethers having the structure RC(CF₃)₂O(CH₂)₃C_nF_2n + 1 are obtained in high yields, when F-tert-butyl alcohol (R = CF₃), F-acetone hydrate (R = O(CH₂)₃C_nF_2n + 1), F-pinacol (R = C(CF₃)₂O(CH₂)₃C_nF_2n + 1) are reacted with 3-perfluoroalkyl-1-propanols (C_nF_2n + 1(CH₂)₃OH, n = 4, 6, 8, 10) in a Mitsunobu reaction (Ph₃P/DIAD [i-PrO₂CN = NCO₂Pr-i]/ether). The parent lipophilic ethers with the structure of (CF₃)₃CO(CH₂)₃C_nH_2n + 1 were prepared analogously using the corresponding fatty alcohols and F-tert-butyl alcohol. To achieve ideal separations, products were transferred to orthogonal phases relative to the other reaction components using fluorous extraction, fluorous solid-organic liquid filtration, or steam-distillation. Selected physical properties including melting and boiling point, together with fluorous partition coefficients of these ethers were determined and the figures obtained were qualitatively analyzed using relevant thermodynamic theories. Some of these ethers are liquids with rather low freezing points and are miscible with fluorocarbon solvents.