Structure and reaction mechanism for the monoacid diol polyester from caprolactone and 2,2?-bis(hydroxymethyl)propionic acid: NMR and melting-point evidence

2001 ◽  
Vol 82 (9) ◽  
pp. 2217-2226
Author(s):  
J. A. Simms ◽  
E. F. McCord
Keyword(s):  
Reaction Mechanism ◽  
Melting Point ◽  
Propionic Acid ◽  
Diol Polyester

Synthesis, X-ray structure determination, and formation of 3,4,5-trichloroguaiacol occurring in kraft pulp spent bleach liquors

1980 ◽  
Vol 58 (8) ◽  
pp. 815-822 ◽  
Author(s):  
K. Lindström ◽  
F. Österberg
Keyword(s):  
Reaction Mechanism ◽  
Melting Point ◽  
Structure Determination ◽  
Kraft Pulp ◽  
Chemical Shifts ◽  
X Ray ◽  
Nmr Chemical Shifts ◽  
Chemical Pulp ◽  
C Nmr

3,4,5-Trichloroguaiacol, which is formed during bleaching of chemical pulp and shown to bioaccumulate in fish, has been synthesized. The structure of the compound has been determined by means of X-ray analysis. The values of the 13C nmr chemical shifts and melting point differ from those previously reported. A reaction mechanism is suggested for the formation of 3,4,5- and 4,5,6-trichloroguaiacol.

The Ritter Reaction Mechanism: New Corroboration in the Synthesis of Arylsulfonyl(thio)propionic Acid N-(1-Adamantyl)amides.

ChemInform ◽  
2003 ◽  
Vol 34 (36) ◽  
Author(s):  
Nina P. Gerasimova ◽  
Nikolai A. Nozhnin ◽  
Valentina V. Ermolaeva ◽  
Anna V. Ovchinnikova ◽  
Yuri A. Moskvichev ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Propionic Acid ◽  
Ritter Reaction ◽  
The Ritter Reaction

The Ritter reaction mechanism: new corroboration in the synthesis of arylsulfonyl(thio)propionic acid N-(1-adamantyl)amides

2003 ◽  
Vol 13 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nina P. Gerasimova ◽  
Nikolai A. Nozhnin ◽  
Valentina V. Ermolaeva ◽  
Anna V. Ovchinnikova ◽  
Yuri A. Moskvichev ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Propionic Acid ◽  
Ritter Reaction ◽  
The Ritter Reaction

scholarly journals Investigation of the reaction mechanism of the hydrodeoxygenation of propionic acid over a Rh(1 1 1) surface: A first principles study

2020 ◽  
Vol 391 ◽  
pp. 98-110
Author(s):  
Wenqiang Yang ◽  
Rajadurai Vijay Solomon ◽  
Osman Mamun ◽  
Jesse Q. Bond ◽  
Andreas Heyden
Keyword(s):  
Reaction Mechanism ◽  
Propionic Acid ◽  
First Principles ◽  
First Principles Study

Preparation of Ti-Al Intermetallics by Aluminum Melt Infiltration-Diffusion Annealing Technique

2007 ◽  
Vol 561-565 ◽  
pp. 367-370
Author(s):  
Li Qing Chen ◽  
Ji Jie Wang ◽  
Lin Chen
Keyword(s):  
High Temperature ◽  
Reaction Mechanism ◽  
Melting Point ◽  
Elevated Temperatures ◽  
Diffusion Annealing ◽  
Compressive Behavior ◽  
Porous Ti ◽  
Temperature Diffusion ◽  
Melt Infiltration ◽  
Long Time

A novel process, of melt infiltration combined with diffusion annealing technique, was developed to prepare Ti-Al intermetallics at temperature lower than ingot melting point. In this process, a porous Ti preform was firstly fabricated and the Al melt was reheated to temperature slightly higher than Al melting point to infiltrate the porous Ti preform by capillary force spontaneously. After long-time high-temperature diffusion annealing, Ti-Al intermetallic compound can be finally synthesized from the bulk Tip+melt Al via diffusion. As example, Ti-46Al intermetallics has been fabricated, and the microstructures and the phases of the as-synthesized intermetallics were characterized by XRD and SEM. The compressive behavior of the as-synthesized Ti-Al at elevated temperatures has been studied and the reaction mechanism involved in the process finally analyzed.

scholarly journals Mechanism of action of 5-aminolaevulinate dehydratase from human erythrocytes

1985 ◽  
Vol 227 (3) ◽  
pp. 1015-1020 ◽  
Author(s):  
P M Jordan ◽  
P N Gibbs
Keyword(s):  
Schiff Base ◽  
Reaction Mechanism ◽  
Propionic Acid ◽  
Mechanism Of Action ◽  
Human Erythrocyte ◽  
Human Erythrocytes ◽  
Substrate Molecule ◽  
Equal Distribution ◽  
Single Turnover ◽  
Porphobilinogen Synthase

Purified 5-aminolaevulinate dehydratase (porphobilinogen synthase, EC 4.2.1.24) from human erythrocytes was incubated initially with limiting amounts of 5-amino [5-14C]laevulinate in a rapid-mixing apparatus. The single-turnover reaction with respect to the bound labelled 5-aminolaevulinate was completed by the addition of unlabelled 5-aminolaevulinate and the resulting radioactive porphobilinogen was isolated and degraded. The 14C label was found to be located predominantly at C-2 of the product, demonstrating that, of the two substrate molecules participating in the reaction, the 5-aminolaevulinate molecule initially bound to the enzyme provides the propionic acid ‘side’ of the porphobilinogen. The same enzyme-[14C]substrate species that yields regiospecific porphobilinogen may be trapped by reaction with NaBH4, showing that the substrate molecule initially bound to the enzyme does so in the form of a Schiff base. A conventional incubation with 5-amino[5-14C]laevulinate yielded porphobilinogen with an equal distribution of the label between C-2 and C-11. The reaction mechanism of the human erythrocyte 5-aminolaevulinate dehydratase thus follows the same course as that of other dehydratases studied in our laboratory by using single-turnover techniques.

Reaction Synthesis of (Ti,Cr) 2AlC/Al2O3 In Situ Solid Solution Composite

2011 ◽  
Vol 480-481 ◽  
pp. 519-522
Author(s):  
Jian Feng Zhu ◽  
Na Han
Keyword(s):  
Solid Solution ◽  
Electron Microscope ◽  
Reaction Mechanism ◽  
Melting Point ◽  
Intermetallic Compound ◽  
Phase Evolution ◽  
Reaction Synthesis ◽  
X Ray ◽  
Scanning Electron

The (Ti,Cr)2AlC/Al2O3 solid solution composite has been synthesized by in situ aluminothermic reduction of the blend powders of Ti, Al, Cr2O3 and carbon black. The phase evolution during the formation of the composite was examined at the temperatures from 700 °C to 1400 °C. Based on the results of X-ray diffractometry (XRD) and differential scanning calorimeter (DSC), a possible reaction mechanism was brought forward to explain the formation of (Ti,Cr)2AlC/Al2O3 solid solution composite. Above the melting point of aluminum, liquid Al reacted with titanium to form the intermetallic compound of TiAl. As the temperature increased to 900 °C, the intermetallic compound of TiAl reacted with TiC to form Ti2AlC. The microstructures of the as prepared samples were also analyzed by the scanning electron microscope (SEM) together with the election dispersive spectroscopy (EDS).

Reaction Synthesis of (Ti,V)2AlC/Al2O3 Composite

2011 ◽  
Vol 230-232 ◽  
pp. 1274-1277
Author(s):  
Jian Feng Zhu ◽  
Na Han
Keyword(s):  
Solid Solution ◽  
Electron Microscope ◽  
Reaction Mechanism ◽  
Melting Point ◽  
Intermetallic Compound ◽  
Phase Evolution ◽  
Reaction Synthesis ◽  
X Ray ◽  
Scanning Electron

The (Ti,V)2AlC/Al2O3 solid solution composite has been synthesized by in situ aluminothermic reduction of the blend powders of Ti, Al, V2O5 and active carbon. The phase evolution during the formation of the composite was examined at the temperature from 500 °C to 1400 °C. Based on the results of X-ray diffractometry (XRD) and differential scanning calorimeter (DSC), a possible reaction mechanism was proposed to explain the formation of (Ti,V)2AlC/Al2O3 solid solution composite. Above the melting point of aluminum, liquid Al reacted with titanium to form the intermetallic compound of TiAl. As the temperature increased to 1300 °C, the intermetallic compound of TiAl reacted with TiC to form Ti2AlC. The microstructures of the as prepared samples were also analyzed by the scanning electron microscope (SEM) together with the election dispersive spectroscopy (EDS).

3-METHOXY-4-HYDROXY-BENZALDEHYD (VANILLIN) ALS METABOLIT VON ADRENALIN UND NORADRENALIN

1964 ◽  
Vol 47 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Helmut Thomas ◽  
Wilhelm Dirscherl
Keyword(s):  
Absorption Spectrum ◽  
Melting Point ◽  
Propionic Acid ◽  
Ir Spectrum ◽  
Vanillic Acid ◽  
Incubation Medium ◽  
Human Liver ◽  
Mandelic Acid ◽  
Post Mortem ◽  
Intermediary Product

ABSTRACT After incubation of 3-methoxy-4-hydroxy-mandelic acid, a metabolite of adrenaline and noradrenaline, with rat liver slices and slices of human liver obtained at post mortem, in addition to vanillic acid one intermediary product was detected by paper chromatography. In the system benzene-propionic acid-water (2:2:1) this showed the same RF-value as 3-methoxy-4-hydroxy-benzaldehyde (vanillin). In the deproteinized incubation medium the substance was precipitated as 2,4-dinitrophenylhydrazone, which after purification and recrystallisation was identified by melting point, absorption spectrum between 220 and 500 mμ, and IR-spectrum as 2,4-dinitrophenylhydrazone of vanillin.

Voids in Irradiated Tungsten and Molybdenum

1969 ◽  
Vol 27 ◽  
pp. 190-191
Author(s):  
Robert C. Rau ◽  
Robert L. Ladd
Keyword(s):  
Melting Point ◽  
Fast Neutron ◽  
Neutron Irradiation ◽  
Elevated Temperatures ◽  
Irradiation Temperature ◽  
The Body ◽  
Face Centered Cubic ◽  
Body Centered Cubic ◽  
Cubic Metals ◽  
Face Centered

Recent studies have shown the presence of voids in several face-centered cubic metals after neutron irradiation at elevated temperatures. These voids were found when the irradiation temperature was above 0.3 Tm where Tm is the absolute melting point, and were ascribed to the agglomeration of lattice vacancies resulting from fast neutron generated displacement cascades. The present paper reports the existence of similar voids in the body-centered cubic metals tungsten and molybdenum.

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