INDUCED INFRARED ABSORPTION OF NITROGEN AND NITROGEN – FOREIGN GAS MIXTURES

1965 ◽  
Vol 43 (12) ◽  
pp. 2331-2343 ◽  
Author(s):  
S. Paddi Reddy ◽  
C. W. Cho
Keyword(s):  
Room Temperature ◽  
Gas Mixtures ◽  
Fundamental Vibration ◽  
Molecular Constants ◽  
Pure Nitrogen ◽  
Helium Mixtures ◽  
Vibration Rotation ◽  
The Individual ◽  
Straight Lines ◽  
Good Agreement

The pressure-induced fundamental vibration–rotation absorption band of nitrogen was studied in the pure gas and in nitrogen–argon, nitrogen–hydrogen, and nitrogen–helium mixtures at room temperature for pressures up to 1 500 atm. The shapes of the absorption profiles obtained in each case were discussed. The enhancement absorption profiles of nitrogen–argon mixtures exhibited the sharpening of the individual branches of the fundamental band with a small frequency shift, while those of nitrogen–hydrogen and nitrogen–helium mixtures indicated a splitting of the Q branch. Binary and ternary absorption coefficients were determined for pure nitrogen and nitrogen – foreign gas mixtures. The graph drawn with (1/ρa2) ∫α(ν)dν vs. ρa for pure nitrogen and those drawn with (1/ρaρb) (∫α(ν)dν)enhancement vs. ρb for mixtures were found to be straight lines. Except for nitrogen–helium mixtures all these straight lines had negative slopes, and this was interpreted as a partial cancelation of the induced moments due to ternary collisions. Applying the theory of Van Kranendonk and using the known molecular constants, the molecular quadrupole moment Q of nitrogen and its derivative Q′ with respect to the internuclear distance at its equilibrium position were determined. The values of Q and Q′ were obtained as 1.1ea02 and 0.97ea0 respectively; the value of Q is in good agreement with that determined by previous investigators.

A comparison of the compressibilities of some gases with that of nitrogen at pressures below one atmosphere

1950 ◽  
Vol 200 (1061) ◽  
pp. 201-218 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Differential Method ◽  
Linear Extrapolation ◽  
Volume Changes ◽  
Pure Nitrogen ◽  
Molecular Weights ◽  
Nitrous Oxide Oxygen ◽  
The Individual ◽  
Straight Lines ◽  
High Degree

A differential method for comparing the compressibilities of gases at pressures below 1 atm. has been developed in which many of the errors inherent in methods employed previously have been to a large extent eliminated, especially those due to meniscus volume changes and capillary depression. Using pure nitrogen as a standard the low-pressure isothermals of carbon monoxide, carbon dioxide, nitrous oxide, oxygen, ethylene and propane have been determined at a temperature of 22-05° C. The deviations of the individual points from straight lines do not in most cases exceed 2 parts in 100,000. In no case, even with propane, was any curvature in the isotherms detectable. The contention of Moles and other recent workers that the molecular weights of liquefiable gases can be determined to a high degree of accuracy by linear extrapolation is rendered highly probable by this fresh evidence.

Ligand Redistribution Equilibria in Aqueous Fluoroberyllate Solutions

1998 ◽  
Vol 53 (11) ◽  
pp. 1294-1300 ◽  
Author(s):  
Michael Schmidt ◽  
Hubert Schmidbaur
Keyword(s):  
Experimental Data ◽  
Ligand Exchange ◽  
Room Temperature ◽  
Chemical Shifts ◽  
Equilibrium Constants ◽  
Individual Species ◽  
Ph Values ◽  
Exchange Processes ◽  
The Individual ◽  
Good Agreement

The composition of aqueous fluoroberyllate solutions has been studied by 9Be and 19F NMR spectroscopy for various ratios of the beryllium and fluorine concentrations, and at different pH values. The equilibrium constants have been determined for the ligand exchange processes, which involve the species [Be(OH2)4]2+, [BeF(OH2)3]+, [BeF2(OH2)2], [BeF3(OH2)]- , and [BeF4]2-. These equilibria are shifted towards [BeF4]2- at high pH. No polynuclear fluoroberyllates have been detected. The fluoride exchange between the individual species is slow on the NMR time scale at room temperature, and separate sharp signals with the expected multiplicity are therefore recorded. Calculated 9Be chemical shifts are in good agreement with experimental data.

scholarly journals HPLC monitored synthesis of R2NCH2 substituted benzene derivatives used as (C,N)-ligands for organometallic compounds

2004 ◽  
Vol 2 (4) ◽  
pp. 563-572 ◽  
Author(s):  
Loredana Soran ◽  
Virginia Coman ◽  
Albert Soran ◽  
Cristian Silvestru
Keyword(s):  
Nmr Spectroscopy ◽  
Room Temperature ◽  
Narrow Range ◽  
Organometallic Compounds ◽  
Hplc Method ◽  
Benzene Derivatives ◽  
Straight Lines ◽  
Correlation Factors ◽  
Good Agreement ◽  
Hplc Data

Abstract2-(Diethylaminomethyl)phenyl bromide and 1,3-bis(dimethylaminomethyl)-benzene, useful ligands for the synthesis of hypervalent organometallic compounds, were prepared and characterized by NMR (1H, 13C, 2D experiments) spectroscopy. Their synthesis was monitored by the HPLC method. The compounds were eluted on a Nucleosil 120 Si column (5 μm, 25×0.4 cm) with n-hexane at room temperature using a 1.0 ml/min flow-rate. The maximum values of absorbance for the studied compounds, excepting the diethylamine, were located in a narrow range around 212 nm, the wavelength used for their UV detection. The diethylamine was detected at 190 nm. The calibration curves are straight lines with correlation factors r>0.995. The HPLC data are in good agreement with those provided by NMR spectroscopy.

INDUCED INFRARED ABSORPTION OF DEUTERIUM IN DEUTERIUM – FOREIGN GAS MIXTURES

1966 ◽  
Vol 44 (11) ◽  
pp. 2893-2903 ◽  
Author(s):  
S. T. Pai ◽  
S. Paddi Reddy ◽  
C. W. Cho
Keyword(s):  
Absorption Band ◽  
Binary Mixtures ◽  
Infrared Absorption ◽  
Room Temperature ◽  
The Other ◽  
Absorption Profile ◽  
Absorption Coefficients ◽  
Helium Mixtures ◽  
Experimental Values ◽  
The Individual

The pressure-induced fundamental infrared absorption band of deuterium was studied in deuterium–helium, deuterium–argon, and deuterium–nitrogen mixtures at pressures up to 1 200 atm at room temperature. The enhancement absorption profile of each mixture shows a well-resolved splitting of the Q branch into two components QP and QR. While the enhancement contours of deuterium–helium mixtures do not exhibit any absorption peaks corresponding to the O and S branches, those of the other two binary mixtures show a pronounced S(2) peak and an indication of several other O and S peaks of the band. Integrated absorption coefficients of the band have been measured for all the mixtures, and the binary and ternary absorption coefficients were determined. The theory of Van Kranendonk and the available molecular parameters of deuterium and the perturbing gases were used to calculate the binary absorption coefficients of the individual lines of the O and S branches and of the quadrupole part of the Q branch of the band in all three binary mixtures. Using these calculated values and the experimental values of the total binary absorption coefficients of these mixtures, the overlap parts of the binary absorption coefficients of the Q branch were estimated.

The fundamental vibration-rotation band of deuterium chloride

1953 ◽  
Vol 218 (1132) ◽  
pp. 37-43 ◽  
Keyword(s):  
Preceding Paper ◽  
Resolving Power ◽  
Vibration Band ◽  
Fundamental Vibration ◽  
Deuterium Chloride ◽  
Isotopic Molecule ◽  
Vibration Rotation ◽  
High Degree ◽  
Very High ◽  
Good Agreement

The fundamental vibration band of deuterium chloride near 5μ has been re-examined using much greater resolving power than previously. The isotopic splitting of the rotation lines has been completely resolved, and a greater number of lines has been measured in each of the branches forming the band. Rotational constants have been determined for the two combining states, and values have also been obtained for the centrifugal stretching constants. The relative values are in very good agreement with those to be expected for a pair of isotopic molecules with the atomic masses concerned. The new value (1·274 6 Å) derived for the bond length in both species of deuterium chloride agrees to a very high degree with that found in the preceding paper for the isotopic molecule hydrogen chloride.

Domain Formation in Synthetic Quartz

1971 ◽  
Vol 29 ◽  
pp. 156-157
Author(s):  
Joseph J. Comer
Keyword(s):  
Electron Beam ◽  
Room Temperature ◽  
Domain Formation ◽  
Synthetic Quartz ◽  
Transmission Electron ◽  
Black Spots ◽  
Diffraction Mode ◽  
Domain Boundaries ◽  
Kikuchi Lines ◽  
Straight Lines

Domains visible by transmission electron microscopy, believed to be Dauphiné inversion twins, were found in some specimens of synthetic quartz heated to 680°C and cooled to room temperature. With the electron beam close to parallel to the [0001] direction the domain boundaries appeared as straight lines normal to <100> and <410> or <510> directions. In the selected area diffraction mode, a shift of the Kikuchi lines was observed when the electron beam was made to traverse the specimen across a boundary. This shift indicates a change in orientation which accounts for the visibility of the domain by diffraction contrast when the specimen is tilted. Upon exposure to a 100 KV electron beam with a flux of 5x 1018 electrons/cm2sec the boundaries are rapidly decorated by radiation damage centers appearing as black spots. Similar crystallographio boundaries were sometimes found in unannealed (0001) quartz damaged by electrons.

Dislocation structures around SiO2 Particles in aged Cu-Cr-SiO2

1978 ◽  
Vol 36 (1) ◽  
pp. 594-595
Author(s):  
N.J. Long ◽  
M.H. Loretto ◽  
C.H. Lloyd
Keyword(s):  
Flow Stress ◽  
Single Crystals ◽  
Room Temperature ◽  
Thin Foil ◽  
Age Hardening ◽  
Dispersion Strengthening ◽  
Accurate Picture ◽  
The Matrix ◽  
Very High ◽  
Good Agreement

IntroductionThere have been several t.e.m. studies (1,2,3,4) of the dislocation arrangements in the matrix and around the particles in dispersion strengthened single crystals deformed in single slip. Good agreement has been obtained in general between the observed structures and the various theories for the flow stress and work hardening of this class of alloy. There has been though some difficulty in obtaining an accurate picture of these arrangements in the case when the obstacles are large (of the order of several 1000's Å). This is due to both the physical loss of dislocations from the thin foil in its preparation and to rearrangement of the structure on unloading and standing at room temperature under the influence of the very high localised stresses in the vicinity of the particles (2,3).This contribution presents part of a study of the Cu-Cr-SiO2 system where age hardening from the Cu-Cr and dispersion strengthening from Cu-Sio2 is combined.

Infrared spectra, rotational correlation functions, and intermolecular mean squared torques in compressed gaseous methane

1968 ◽  
Vol 46 (11) ◽  
pp. 1331-1340 ◽  
Author(s):  
R. L. Armstrong ◽  
S. M. Blumenfeld ◽  
C. G. Gray
Keyword(s):  
Correlation Functions ◽  
Theoretical Calculations ◽  
Dominant Contribution ◽  
Dispersion Interactions ◽  
Fundamental Vibration ◽  
Order Of Magnitude ◽  
The Mean ◽  
Vibration Rotation ◽  
Experimental Values ◽  
Rotational Correlation

Extensive measurements of the methane ν3 and ν4 fundamental vibration–rotation bands in CH4–He mixtures and the ν3 band in CH4–He, CH4–N2, and CD4–He mixtures have been carried out in infrared absorption at 295 °K to pressures of 3000 atm. Some profiles of the ν3 band in CH4–Ar mixtures and in pure CH4 have also been obtained. Rotational correlation functions, band moments, and intermolecular mean squared torques have been determined from the ν3 band profiles. Theoretical calculations of the mean squared torque due to anisotropic multipolar, induction and dispersion interactions have been carried out. The theoretical and experimental torques are in order-of-magnitude agreement for the CH4–N2 and CH4–CH4 systems; for CH4–He, CD4–He, and CH4–Ar the theoretical values are two to three orders of magnitude too small to account for the experimental values, indicating that in these cases the dominant contribution to the torques is given by the anisotropic overlap forces.

Defect Structure of MEV Si Implantation in GaAs

1988 ◽  
Vol 126 ◽  
Author(s):  
S.-Tong Lee ◽  
G. Braunstein ◽  
Samuel Chen
Keyword(s):  
Free Surface ◽  
Defect Structure ◽  
Room Temperature ◽  
Surface Region ◽  
Peak Position ◽  
Lattice Disorder ◽  
Depth Profiles ◽  
Trim Calculation ◽  
Good Agreement

ABSTRACTThe defect and atomic profiles for MeV implantation of Si in GaAs were investigated using He++ channeling, TEM, and SIMS. Doses of 1–10 × 1015Si/cm2 at 1–3 MeV were used. MeV implantation at room temperature rendered only a small amount of lattice disorder in GaAs. Upon annealing at 400°C for 1 h or 800°C for 30 a, we observed a ‘defect-free’ surface region (- 1 μ for 3 MeV implant). Below this region, extensive secondary defects were formed in a band which was 0.7 μ wide and centered at 2 μ for 3 MeV implant. These defects were mostly dislocations lying in the [111] plane. SIMS depth profiles of Si implants showed the Si peak to be very close to the peak position of the defects. The experimental profiles of Si were compared to the TRIM calculation; generally good agreement existed among the peak positions.

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