PHYSICAL CONSTANTS AND ESTIMATION OF STEREOISOMERIC 2,3-BUTANEDIOLS

1951 ◽  
Vol 29 (10) ◽  
pp. 885-894 ◽  
Author(s):  
R. W. Watson ◽  
J. A. R. Coope ◽  
J. L. Barnwell
Keyword(s):  
Refractive Index ◽  
Pilot Plant ◽  
Experimental Error ◽  
Specific Rotation ◽  
Optically Active ◽  
Temperature Relation ◽  
Aerobacter Aerogenes ◽  
Physical Constants ◽  
Beet Molasses

The refractive index – temperature relation for optically active and racemic diols is linear, with [Formula: see text] from 25° to 40°C.: for the meso-isomer [Formula: see text] from 25° to 50°C. The specific rotation [Formula: see text]. Measurements of [Formula: see text] and [Formula: see text] in suitably purified mixtures of stereoisomers allow calculation of the percentage of each isomer present. Tests of the method on known mixtures of all three stereoisomers show an experimental error of ±3%. Analyses of five diol samples from pilot plant fermentations of beet molasses by Aerobacter aerogenes reveal 65–87% meso-, from 2 to 16% dextro-, and from 0 to 33% racemic 2,3-butanediol.

scholarly journals Microwave-assisted synthesis and characterization of some optically active poly(ester-imide) thermoplastic elastomers

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Saeed Zahmatkesh ◽  
Abdol Reza Hajipour
Keyword(s):  
Thermal Analyses ◽  
Specific Rotation ◽  
Thermoplastic Elastomers ◽  
Optically Active ◽  
Microwave Assisted Synthesis ◽  
H Nmr ◽  
Microwave Assisted ◽  
Diacid Chloride ◽  
Elemental Analyses

AbstractPyromellitic dianhydride (1) was reacted with L-leucine (2) to result in [N,N'-(pyromellitoyl)-bis-L-leucine diacid] (3). This compound (3) was converted to N,N'-(pyromellitoyl)-bis-L-leucine diacid chloride (4) by reaction with thionyl chloride. The microwave-assisted polycondensation of this diacid chloride (4) with polyethyleneglycol-diol (PEG-200) and/or three synthetic bisphenols furnish a series of new PEIs and Co-PEIs in a laboratory microwave oven (Milestone). The resulting polymers and copolymers have inherent viscosities in the range of 0.31- 0.53 dl g-1. These polymers are optically active, thermally stable and soluble in polar aprotic solvents such as DMF, DMSO, NMP, DMAc and sulfuric acid. All of the above polymers were fully characterized by IR spectroscopy, 1H NMR spectroscopy, elemental analyses, specific rotation and thermal analyses. Some structural characterizations and physical properties of these optically active PEIs and Co-PEIs are reported.

STUDIES IN FISH OILS: 3. SOME OBSERVATIONS ON THE HYDROGENATION OF PILCHARD OIL

1932 ◽  
Vol 7 (1) ◽  
pp. 521-535
Author(s):  
H. N. BROCKLESBY ◽  
F. CHARNLEY
Keyword(s):  
Refractive Index ◽  
Iodine Value ◽  
Hydrogen Absorption ◽  
Experimental Error ◽  
Fish Oils ◽  
Hydrogenated Oil ◽  
Logarithmic Type

Rate curves for the hydrogenation of pilchard oil show two distinct branches which represent more nearly reactions of a linear rather than a logarithmic type. The effect of the accumulation of impurities on the hydrogen absorption curves studied is shown to be negligible.The relationship between refractive index and iodine value of the hydrogenated oil can be expressed as an equation of the form n = a + bI + cI2, where n = the refractive index, I the iodine value, and a, b and c are constants.Within the limits of experimental error, the fall in iodine value is directly proportional to hydrogen absorption but is slightly different over the two regions of hydrogenation.

REFRACTIVE INDEX OF He4: LIQUID

1958 ◽  
Vol 36 (7) ◽  
pp. 884-898 ◽  
Author(s):  
M. H. Edwards
Keyword(s):  
Refractive Index ◽  
Experimental Error ◽  
Saturated Vapor ◽  
Liquid Density ◽  
Phase Index ◽  
Vertical Tangent ◽  
Group Refractive Index ◽  
Relative Measurements ◽  
Λ Point

Changes in the phase refractive index n with temperature have been measured between 1.6 and 4.2° K at λ = 5462.27 Å, for liquid He4 at its saturated vapor pressure, using a metal optical cryostat and a Jamin interferometer. A novel adaptation of the Jamin interferometer has been made so that, in addition, an absolute determination of the group refractive index, nG, could be made using white light of "effective wavelength" 5595 ± 40 Å. When the dispersion correction is made, the phase index for the Hg green line at T55E = 3.700° K is n = 1.026124 ± 0.000035. The relative measurements have been adjusted to this value. The more than 200 experimental points show a random scatter of less than 5 × 10−6 in index. Using Kerr's density data the polarizability is thus (N0α) = (0.12454 ± 0.00021) cm3 mole−1 at λ = 5462.27 Å, for liquid He4 at 3.7 °K. Within experimental error (N0α) is found to be independent of temperature. Thus the refractive index data may be considered as a measurement of the liquid density and coefficient of expansion.The region near the λ-point is of special interest. The expansion coefficient determined from the refractive index, βn, may be represented within experimental error by 103βnI = +41.5 + 14.5 log|T−Tλ| for T > Tλ, from about 0.1° above Tλ to within 0.01° of Tλ; and by 103βnII = −1.5 + 14.5 log |T−Tλ| for T < Tλ, from about 0.1° below Tλ to within 0.002° of Tλ. This implies that the density–temperature curve has both a vertical tangent and a point of inflection at the λ-point; and that the maximum in density occurs about 0.001° above the λ-point.

The refractive indices and Verdet constants of the inert gases

1960 ◽  
Vol 259 (1298) ◽  
pp. 424-431 ◽  
Keyword(s):  
Experimental Data ◽  
Refractive Index ◽  
Atomic Hydrogen ◽  
Experimental Error ◽  
Atomic System ◽  
Inert Gases ◽  
Refractive Indices ◽  
Verdet Constant

A method is suggested by which the refractive index and Verdet constant of an atomic system may be derived theoretically. It is applied to atomic hydrogen and to the inert gases and a comparison is made with experimental data. The Verdet constant of neon is not anomalous. The origin of the suggestion appears to be an underestimate of the experimental error. The analysis yields values of th e polarizabilities of th e inert gases which are respectively He, 1-384; Ne, 2-663; Ar, 11-080; K r, 16-734; X e, 27-292 in units of α 3 0

scholarly journals New routes to chiral phosphines

1985 ◽  
Author(s):  
Άγγελος Βουγιούκας
Keyword(s):  
Dicarboxylic Acid ◽  
Phosphine Oxide ◽  
Experimental Error ◽  
Phosphonium Salt ◽  
Optically Active ◽  
Side Chain ◽  
Phosphonium Salts ◽  
Unstable Compound ◽  
Chiral Phosphines ◽  
Optically Pure

The reaction of diphenyl(2-trimethylsilylethyl)phosphine with methyl trifluoromethanesulphonate gave a phosphonium salt from which the side-chain was cleaved with F ® , yielding diphenylmethylph osphine. A slower reaction with the triphenylsilyl-analogue gave the corresponding phosphine oxide. When the cleavage of a diphosphonium salt was attempted the product was a mixture of 1,3-bis-(diphenylphosphino)propane and diphenyl(2-trimethylsilylethyl)phosphine in 1:2 ratio showing the cleavage to be unselective. ß-Silylphosphonium salts derived from 2,2-dimethyl-H-methylene- 1 , 3-dioxolane reacted with F® to provide completely selective cleavage of the dioxolanyl side-chain, and a related bis-phosphonium salt gave only diphenyl(2-trimethylsilylethyl)phosphine under similar conditions. Greater selectivity towards fragmentation of the silylated side-chain was achieved with triethoxysilylethyl derivatives and 1, 3-bis-(diphenylphosphino)propane as well as 1,4-bis-(diphenylphosphino)butane were prepared in this way, in 86% and 9^% yield respectively. It was found that the dioxolanylmethyl side-chain was more readily cleaved from phosphonium salts than was 2-(triethoxylsily1)ethyl, however. In similar manner, reaction of 2-(trimethylsilyloxyethy1)- methyldiphenylphosphonium trifluoromethanesulphonate with Fö gave methyldiphenylphosphine oxide. The same reaction occurred when the corresponding hydroxyethylphosphine was treated with KH. This method was shown to be applicable to the synthesis of biphosphine oxides. Nevertheless, application to dioxolanylmethyl phosphonium salts again led to px^ef erential loss of that side-chain; this caused a change to utilisation of the trans-1,2-dimethylcyclobutyl backbone. The optically active o-anisylmethylphenylphosphine oxidewas prepared in both enantTomeric forms by a literature route. Reaction of the R-isomer with (iPr)2NLi and then acetone led to a new phosphine oxide which was reduced with E t 3N/Cl3$iH and reacted with methyl trifluoromethanesulphonate to giveR - (2-hydroxy-2-methylpropyl)(o-methoxyphenyl)methylphenylphosphonium trifluoromethanesplphonate. This reacted with KH to give the parent phosphineOKas R-enantiomer, optically pure within experimental error. “ A new route for the resolution of trans-cyclobutane-1,2-dicarboxylic acid has been developed. This involved the preparation of the bis-ephedrinium amide and its separationinto diastereomers by silica chromatography. The enantiomers were converted into SS and RR t r a n s - 1 ,2-cyclobutanedimethanolof 100% and 88% optical purTTy respectively. Whilst it proved possible to prepare the racemic bis-trifluoromethanesulphonate, it was an unstable compound and the optically active analogues could not be isolated in several attempts.

SYNTHESIS OF DIPALMITOYL-L-α-GLYCEROPHOSPHORIC ACID DERIVATIVES, AS POSSIBLE INTERMEDIATES FOR SYNTHESIS OF GLYCERYLPHOSPHATIDES

1960 ◽  
Vol 38 (1) ◽  
pp. 297-300 ◽  
Author(s):  
N. Z. Stanacev ◽  
M. Kates
Keyword(s):  
Melting Point ◽  
Phosphatidic Acid ◽  
Good Yield ◽  
Dimethyl Ester ◽  
Specific Rotation ◽  
Optically Active ◽  
Phosphatidic Acids ◽  
Alternate Synthesis

Using Verkade's method for the preparation of DL-α-phosphatidic acids, optically active dipalmitoyl-L-α-phosphatidic acid and its derivatives were prepared in good yield. The free dipalmitoyl-L-α-phosphatidic acid and its dimethyl ester were identical in melting point and specific rotation with the same compounds originally prepared by Baer using an alternate synthesis.

scholarly journals Synthesis and Characterization of New Optically Active Poly (ethyl L-lysinamide)s and Poly (ethyl L-lysinimide)s

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Saeed Zahmatkesh ◽  
Mohammad Reza Vakili
Keyword(s):  
Nmr Spectroscopy ◽  
Elemental Analysis ◽  
Specific Rotation ◽  
Viscosity Measurement ◽  
Optically Active ◽  
Inherent Viscosity ◽  
Synthesis And Characterization

Ethyl L-lysine dihydrochloride was reacted with three different dianhydrides to yield the poly (ethyl L-lysinimide)s ( NMR spectroscopy, elemental analysis, WAX diffraction, TGA, inherent viscosity measurement, and specific rotation.

Microbial conversion of optically active (R) 3 Chloro-1,2-propandiol by Clavispora lusitaniae MGR5 KY209902

2021 ◽  
Vol 16 (7) ◽  
pp. 23-29
Author(s):  
Kumarasamy Suresh ◽  
Selvaraj Vasuki ◽  
Narayanan Mathiyazhagan ◽  
Ranganathan Muthusamy
Keyword(s):  
Ir Spectrum ◽  
Functional Group ◽  
Dynamic Properties ◽  
Synthetic Medium ◽  
Broad Band ◽  
Specific Rotation ◽  
Optically Active ◽  
Microbial Conversion ◽  
Ph Change ◽  
Clavispora Lusitaniae

The MCH assimilation Clavispora lusitaniae MGR5 (KY209902) was isolated from sugarcane juice using a screening medium. The preliminary assimilation was exercised with Clavispora lusitaniae MGR5 grown on synthetic medium and assimilation by pH change of the medium was observed. The specific rotation of R-3- Chloro-1,2-propanediol was -6 (c=2.5, in C2H5OH) in conditions with enatiomeric excess of 92.8 % Clavispora lusitaniae MGR5 product. The sharp peaks in HPLC spectrum of R 3 Chloro-1,2-propanediol in the retention time peak was of 2.38 min and concentration 100%. The structural and dynamic properties of R-3-Chloro-1,2-propanediol in GCMS spectrum were obtained. The IR spectrum, a shallow broad band at wavelength 3309.8 signifies the presence of O-H stretching, the narrow peak at 1087.85 indicates the presence of C=O stretching in conjugation with functional group of R- 3 Chloro-1,2-propanediol(C3H7ClO2). These results concluded that the strain assimilated with stereo inversion of R-3- Chloro-1,2-propanediol via RS 3- chloro-1,2-propanediol. The possibility to produce optically active R-3- Chloro-1,2-propanediol was discussed.

Optically active polymer: synthesis and characterization of new optically active poly (hydrazide-imide)s incorporating L- leucine

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Abdol Reza Hajipour ◽  
Saeed Zahmatkesh ◽  
Arnold E. Ruoho
Keyword(s):  
Thermo Gravimetric Analysis ◽  
Specific Rotation ◽  
Optically Active ◽  
Gravimetric Analysis ◽  
Optically Active Polymer ◽  
Scanning Calorimetry ◽  
Thermo Gravimetric ◽  
Good Thermal Stability ◽  
H Nmr

AbstractThis paper deals with the polycondensation between a chiral diacyl chloride (N,N′-Pyromelliticdiimido-di-L-leucine chloride) and six different dihydrazides. The corresponding poly (hydrazide-imide)s which have been obtained in quantitative yields are moderately soluble in polar aprotic solvents, have good thermal stability and optical activity. The synthetic compounds have been characterized by IR, UV and 1H NMR spectroscopy, elemental analysis and specific rotation. The thermal properties of the polymers (10 and 15) have been studied by thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC).

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