The Vibrational Spectra of Methyl Cyanoacetate and Methyl Cyanoacetate-d3

1974 ◽  
Vol 52 (17) ◽  
pp. 3057-3062 ◽  
Author(s):  
Deepali Sinha ◽  
J. E. Katon
Keyword(s):  
Liquid Phase ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Vibrational Assignment ◽  
Conformational Isomers ◽  
Solid Phases ◽  
Liquid And Solid Phases

The i.r. spectra of methyl cyanoacetate in both liquid and solid phases and of methyl cyanoacetate-d3 in the liquid phase have been recorded in the region 4000–250 cm−1. The Raman spectra of both the compounds in the liquid phase have also been recorded. A tentative vibrational assignment has been made both for the light and the heavy ester. Evidence is presented for the existence of conformational isomers in the liquid phase.

Perfluormethyl-Element-Liganden, XI Die Schwingungsspektren von (CF3)2EMn(CO)5 (E=P, As) / Perfluoromethyl Element Ligands, XI. Vibrational Spectra of (CF3)2EMn(CO)5 (E = P, As)

1975 ◽  
Vol 30 (7-8) ◽  
pp. 539-543 ◽  
Author(s):  
Reinhard Demuth ◽  
Joseph Grobe ◽  
Robert Rau
Keyword(s):  
Liquid Phase ◽  
Force Field ◽  
Gas Phase ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Normal Coordinate Analysis ◽  
Ir And Raman Spectra ◽  
Normal Coordinate ◽  
Ir And Raman

The gas phase IR and liquid phase IR and Raman spectra of (CF3)2PMn(CO)5 and (CF3)2AsMn(CO)6 have been recorded. The spectra are assigned on the basis of a normal coordinate analysis using a transferred force field.

The Vibrational Spectra of α-Bromoacetaldehyde Dimethyl Acetal and Related Molecules

1975 ◽  
Vol 29 (6) ◽  
pp. 501-506 ◽  
Author(s):  
J. E. Katon ◽  
Philip D. Miller
Keyword(s):  
Liquid Phase ◽  
Infrared Spectra ◽  
Vibrational Spectra ◽  
Low Temperatures ◽  
Conformational Equilibrium ◽  
Dimethyl Acetal ◽  
Vibrational Assignment ◽  
Crystal State ◽  
Apparent Evidence

The complete vibrational spectra of α-bromoacetaldehyde dimethyl acetal and α-bromoacetaldehyde dimethyl s6 have been recorded on the pure liquids, and a tentative vibrational assignment has been proposed. The infrared spectra of both compounds in the crystal state have also been recorded at low temperatures. There is no apparent evidence of a conformational equilibrium in the liquid phase. The infrared spectra of three other acetals have been recorded, and the data from all of the compounds are discussed in terms of previously proposed group frequencies of acetals in both the infrared and Raman.

scholarly journals Application of equilibrium phase diagrams for calculation of segregation kinetics during two-component melt cooling

2020 ◽  
Vol 63 (2) ◽  
pp. 129-134
Author(s):  
A. D. Drozin ◽  
E. Yu. Kurkina
Keyword(s):  
Liquid Phase ◽  
Equilibrium State ◽  
Cross Section ◽  
Diffusion Coefficients ◽  
Solid Phase ◽  
Equilibrium Phase ◽  
Minimum Size ◽  
Two Component ◽  
Solid Phases ◽  
Liquid And Solid Phases

According to the equilibrium state diagrams, when the melt is cooled to a certain temperature below liquidus, compositions of liquid and solid phases are uniquely determined by corresponding curves in the diagram. However, it does not happen in reality. For equilibrium (which the diagram describes), it is necessary that the melt is maintained indefinitely at each temperature, or thermal conductivity of liquid and solid phases, and the diffusion coefficients of their components, are infinitely large. We made an attempt to find out how these processes occur in reality. In this work, we consider the growth of individual crystal during cooling of a two-component melt. Mathematical model is constructed based on the following. 1. The melt area with volume corresponding to one grain, the periphery of which is cooled according to a certain law, is considered. 2. At the initial instant of time, a crystal nucleus of a certain minimum size is in the liquid. 3. At the surface of crystal, compositions of liquid and solid phases correspond to equilibrium state diagram at a given temperature on its surface. 4. Changes in temperature and composition in liquid and solid phases occur according to the laws of heat conduction and diffusion, respectively. As the melt gets cold and the crystal grows, the liquid phase is enriched in one component and depleted in another, the solid phase – on the contrary. Since the diffusion coefficients of the components in the solid phase are small, the composition of the crystal does not have time to completely equalize its cross section. The model proposed in the work allows us to study this phenomenon, to calculate for each cooling mode how the composition of the crystal will vary over its cross section. The calculations have shown that the temperature equalization occurs almost instantly, and composition of the liquid phase equalizes much slower. Equalization of the solid phase composition does not occur in the foreseeable time. The results of the work will help to improve technology of generation of alloys with an optimal structure.

scholarly journals Formation of Interfacial Reaction Layers in Al2O3/SS 430 Brazed Joints Using Cu-7Al-3.5Zr Alloys

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 990 ◽  
Author(s):  
Hoejun Heo ◽  
Hyeonim Joung ◽  
Keeyoung Jung ◽  
Chung-Yun Kang
Keyword(s):  
Liquid Phase ◽  
Interfacial Reaction ◽  
Eutectic Temperature ◽  
Liquid Phases ◽  
430 Stainless Steel ◽  
Brazed Joints ◽  
Solid Phases ◽  
Α Al2o3 ◽  
Kinetics Of ◽  
Liquid And Solid Phases

The formation of interfacial reaction layers was investigated in an α-Al2O3/430 stainless steel (SS430) joint brazed using a Cu-7Al-3.5Zr active brazing alloy. Brazing was conducted at above its eutectic temperature of 945 °C and below liquidus 1045 °C, where liquid and solid phases of the brazing alloys coexists. At 1000 °C, the liquid phase of the brazing alloy was wet onto the α-Al2O3 surface. Zr in the liquid phase reduced α-Al2O3 to form a continuous ZrO2 layer. As the dwell time increased, Zr in the liquid phases near α-Al2O3 interface was used up to thicken the reaction layers. The growth kinetics of the layer obeys the parabolic rate law with a rate constant of 9.25 × 10−6 cm·s−1/2. It was observed that a number of low yield strength Cu-rich particles were dispersed over the reaction layer, which can release the residual stress of the joint resulting in reduction of crack occurrence.

The Vibrational Spectra and Structure of Dimethyl Carbonate and its Conformational Behavior

1975 ◽  
Vol 53 (9) ◽  
pp. 1378-1386 ◽  
Author(s):  
J. E. Katon ◽  
M. D. Cohen
Keyword(s):  
Liquid Phase ◽  
Infrared Spectra ◽  
Dimethyl Carbonate ◽  
Solid Phase ◽  
Equilibrium Mixture ◽  
Vibrational Assignment ◽  
Enthalpy Difference ◽  
Oriented Polycrystalline ◽  
Phase Data ◽  
Liquid And Solid Phases

The infrared spectra of dimethyl carbonate in the liquid and solid phases and the Raman spectrum of the liquid phase are reported. The evidence suggests that dimethyl carbonate exists as an equilibrium mixture of at least two conformers in the liquid state. An experimental value for the enthalpy difference of the two conformers of 2.6 ± 0.5 kcal/mol is obtained from the temperature dependency of the infrared spectrum.Dimethyl carbonate crystallizes as an oriented polycrystalline film and polarized infrared spectra of the solid have been obtained. These have been utilized, along with the liquid phase data to obtain an improved vibrational assignment. There appears to be a solid–solid phase change in dimethyl carbonate in the vicinity of 140 K, but the details of this change are not known.

Vibrational Spectra of N2H5HC2O4 and N2D5DC2O4

1975 ◽  
Vol 53 (9) ◽  
pp. 1387-1392 ◽  
Author(s):  
R. Savoie ◽  
M. Guay
Keyword(s):  
Phase Transition ◽  
High Temperature ◽  
Low Temperature ◽  
Crystal Structures ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Unit Cell ◽  
Infrared And Raman Spectra ◽  
Solid Phases ◽  
High Temperature Modification

Infrared and Raman spectra of N2H5HC2O4 and N2D5DC2O4 have been recorded at various temperatures between 77 and 300 K. The results at 300 K are consistent with the known crystal structures of these solids. A phase transition has been detected at ∼ 240 K in N2D5DC2O4 and although there are similarities between the two stable solid phases of this compound, the low-temperature form appears to be centrosymmetric and to have a larger unit cell than the high-temperature modification.

THE VIBRATIONAL SPECTRA OF ACETALDEHYDE AND ACETALDEHYDE-d1

1956 ◽  
Vol 34 (8) ◽  
pp. 1083-1092 ◽  
Author(s):  
J. C. Evans ◽  
H. J. Bernstein
Keyword(s):  
Raman Spectra ◽  
Infrared Spectra ◽  
Vibrational Spectra ◽  
Vibrational Assignment ◽  
Depolarization Ratios

The Raman spectra of liquid CH3CHO and CH3CDO were obtained photo-electrically and depolarization ratios measured. Infrared spectra of the vapors and solids were also obtained. A vibrational assignment is given and the spectra correlated. The vibrational spectra of the acetyl halides reported in the literature are also correlated.

Vibrational Spectra and Structures of the Solid Phases of Germane

1974 ◽  
Vol 52 (2) ◽  
pp. 327-335 ◽  
Author(s):  
Nguyen Dinh The ◽  
J.-M. Gagnon ◽  
R. Belzile ◽  
A. Cabana
Keyword(s):  
Crystal Structure ◽  
Phase I ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Stable Phase ◽  
Spectral Changes ◽  
Lower Symmetry ◽  
Intermediate Phases ◽  
Solid Phases

This paper reports the i.r. and Raman spectra of the four solid phases of GeH4. Pure and mixed isotopic crystals have been examined. Marked spectral changes are observed at every transition. The interpretation of the spectra, based upon the Halford–Hornig approach, provides information on the crystal structure of each form. Phase I is plastic and molecules probably lie at sites of symmetry T or Td. The spectra of the two intermediate phases are consistent with site symmetries of either D2d, S4, C3v or C3 but the two former are favored. The stable phase below 63 °K is of lower symmetry, the molecules lying at sites of either D2, C2v, C2, C5, or C1, symmetry. Possible factor groups are proposed for phases II, III, and IV. The molecules are found to occupy only one set of equivalent sites in each of the phases.

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