Showing papers in "Applied Spectroscopy in 1969"
TL;DR: In this paper, Raman radiant intensities and depolarization ratios measured for gases with mercury arc irradiation and photoelectric detection have been collected, and the observed intensities have been reduced to values of the scattering activity, gj (45αj12+7γj12).
Abstract: Raman radiant intensities and depolarization ratios measured for gases with mercury arc irradiation and photoelectric detection have been collected. The observed intensities have been reduced to values of the scattering activity, gj (45αj12+7γj12). The scattering activity and Raman scattering cross sections are explicitly related. Data for strong sharp bands are accurate to about ± 5% – 10%, while data for weak and broad bands are less accurate.
190 citations
TL;DR: In this article, the rotational spectrum of gaseous F2 has been used to determine a rotational constant of B0=0.8841±0.0006 cm−1.
Abstract: Various schemes are compared for measuring depolarization factors in Raman spectra with laser excitation. Optical systems are discussed for producing a laser beam free of unwanted emission lines and for focusing scattered light on the slit and on the detector. The rotational spectrum of gaseous F2 has been used to determine a rotational constant of B0=0.8841±0.0006 cm−1, corresponding to r0=1.4168±0.0005 A.
104 citations
TL;DR: In this paper, the infrared and Raman spectra of triphenyl compounds of Group VA elements PPh3, Asph3, SbPh3 and BiPh3 have been reported in the 530-100 cm−1 region.
Abstract: The infrared and Raman spectra of triphenyl compounds of Group VA elements PPh3, AsPh3, SbPh3, and BiPh3 (Ph represents the phenyl group), have been reported in the 530–100 cm−1 region. The metal–phenyl stretching and bending vibrations have been assigned with the aid of approximate normal coordinate analysis and depolarization ratios of Raman lines.
98 citations
TL;DR: In this paper, the properties of the complexes of the Mn (II), Fe (II, Co(II), Ni (II) and Cu(II) halides with pyrazine (1,4-diazine), pyrimidine and pyridazine (1 2-dizine) were investigated.
Abstract: The complexes of the Mn (II), Fe (II), Co(II), Ni(II), and Cu(II) halides with pyrazine (1,4-diazine), pyrimidine (1,3-diazine), and pyridazine (1,2-diazine) were prepared and studied by various physical methods. Reflectance spectra, infrared spectra from 4000-80 cm−1, and magnetic moments were determined. The data are suggestive of an octahedral environment involving halide and azine bridging in the 1: 1 complexes, and an octahedral environment involving halide bridging and terminal azines in the 1: 2 complexes.
85 citations
TL;DR: Far-infrared spectroscopic analysis of minerals and inorganics was investigated in this paper, where the first results were obtained for 18 different types of minerals, including 8 sulfides, 3 oxides, 4 carbonates, and 4 sulfates.
Abstract: Far-infrared spectroscopic analysis of minerals and inorganics was investigated. Far-infrared spectra, 200 to 50 cm−1 (50 to 200 μ), were obtained for 18 different minerals and inorganics, including 8 sulfides, 3 oxides, 3 carbonates, and 4 sulfates, many for the first time. Original analytical applications were made on samples of practical interest. These included the identification of cinnabar in a high-quartz ore, cuprite and tenorite in a mixture, calcite and dolomite in a coal refuse sample, dawsonite and dolomite in an oil shale, thenardite in a boiler deposit, and ferrous sulfate in the surface film on pyrite.
56 citations
TL;DR: In this article, major developments in the understanding of the physics and chemistry of the atmospheric pressure spark discharge are presented and commented upon, including work in the areas of equipment, initial gap breakdown, spark channel formation, electrode sampling phenomena, sample propagation phenomena, excited state production, related plasma physics, and counter electrode phenomena.
Abstract: Major developments in the understanding of the physics and chemistry of the atmospheric pressure spark discharge are presented and commented upon. These include work in the areas of equipment, initial gap breakdown, spark channel formation, electrode sampling phenomena, sample propagation phenomena, excited state production, related plasma physics, and counter electrode phenomena.
56 citations
TL;DR: The integral reflection coefficient (R) was measured for the (200) planes in LiF using a double crystal spectrometer over the wavelength range 0.7-2.1 A as mentioned in this paper.
Abstract: The integral reflection coefficient R was measured for the (200) planes in LiF using a double crystal spectrometer over the wavelength range 0.7–2.1 A. For cleaved LiF, R was about 0.7 × 10−4 rads cornpared to 0.3 × 10−4 calculated for the theoretically perfect crystal case. After abrading with 15–20 μ carborindum, R increased to 2.90 × 10−4 at the 0.7-A. end of the range and to 3.68 × 10−4 at the 2.1-A end. For a flexed and reflattened crystal, R increased further to 9.45 × l0−4 at the 0.7-A end of the range but was not improved over the abraded crystal a t the 2.1-A end. Theoretical R values for mosaic graphite were compared with LiF. The value for graphite act 1.66 A was 4.5 times higher than that calculated for mosaic LiF and 1.3 times higher than the measured graphite values of Gould, Bates, and Sparks. It appears that, one can approximate theoretical mosaic crystals by either distorting a nearly perfect crystal srich as LiF or by orienting powder crystallites as in the case of graphite.
23 citations
TL;DR: In this paper, the usefulness of cross-excitation by electric discharge to intensify spectral emission from plasmas generated by a laser micorprobe was extended to a sampling resolution of 10-25 μ without burning the peripheral zone.
Abstract: The usefulness of cross-excitation by electric discharge to intensify spectral emission from plasmas generated by a laser micorprobe was extended to a sampling resolution of 10–25 μ without burning the peripheral zone. This proved practical for sampling single biological cells for elemental analysis. It was accomplished by modifications in shape of the carbon electrode tips, their positioning, and the amount of spark energy used in the cross-excitation.
18 citations
TL;DR: In this article, a review of the development of low-temperature infrared spectroscopy to facilitate the study of structure and thermodynamic properties of molecules is presented, including a literature review with 612 references.
Abstract: A historical discussion of the development of low-temperature infrared spectroscopy to facilitate the study of structure and thermodynamic properties of molecules is presented. This includes a literature review with 612 references.
17 citations
TL;DR: The mass spectra of the following compounds are reported: (1) the π-cycloheptatrienyl derivatives C5H5MC7H7 (M = V and Cr); (2) the δ-pyrrolyl derivative C 5H5FeC4H4N; (3) the ethylene derivative C2H5Rh (C2H4)2; (4) the 1,5-cyclooctadiene derivatives (C5H 5MC8H12) and (5) the trim
Abstract: The mass spectra of the following compounds are reported: (1) the π-cycloheptatrienyl derivatives C5H5MC7H7 (M = V and Cr); (2) the π-pyrrolyl derivative C5H5 FeC4H4N; (3) the ethylene derivative C5H5Rh (C2H4)2; (4) the 1,5-cyclooctadiene derivatives C5H5MC8H12 (M = Rh or Ir); (5) the trimethylplatinum derivative (CH3)3PtC5H5; (6) the nickel and palladium complexes C3H5PdC5H5, C10H12OCH3PdC5H5, and C5H5NiC13H17. The following features of particular interest were observed: (1) evidence for elimination of neutral C6H6 fragments from the C5H5-MC7H7 compounds; (2) evidence for elimination of C2H2, HCN, C2H2N, C4H4N, and Fe fragments from the parent ion of C5H5FeC4H4N; (3) evidence for stepwise elimination of ethylene ligands from C5H5Rh (C2H4)2; (4) evidence for relatively weak metal–π-cyclopentadienyl bonds in the nickel and palladium derivatives.
17 citations
TL;DR: In this article, the attenuated total reflection (ATR) has been used for quantitative analysis of textile fabrics. But, as equipment for making internal reflection measurements improves and as the phenomenon is more clearly understood, it is becoming more feasible.
Abstract: Internal reflection spectroscopy (also known as attenuated total reflection—ATR) has been applied primarily as a qualitative tool. As equipment for making internal reflection measurements improves and as the phenomenon is more clearly understood, its use for quantitative analysis is becoming more feasible. Katlafsky and Keller have demonstrated its accuracy for sampling strongly absorbing liquids and Medick has discussed its use in the quantitative analysis of adhesives and films. Chan and Hawkins have used internal reflection spectroscopy to obtain quantitative data on the degradation of plastic surfaces. Much unpublished work has been done in the measurement of coating thickness, in some cases quantitative studies have been made on multilayer systems. Wilks has described techniques for making quantitative measurements on mixed textile fabrics, while McCall et al. have discussed quantitative measurements of coatings and chemical treatments on cotton fibers.
TL;DR: The mass spectra of the following olefin derivatives of metal carbonyls have been investigated: (a) Arene-tungsten tricarbonyl complexes of toluene, p-xylene, and mesitylene, as discussed by the authors.
Abstract: The mass spectra of the following olefin derivatives of metal carbonyls have been investigated: (a) Arene-tungsten tricarbonyl complexes of toluene, p-xylene, and mesitylene; (b) The cyclo-heptatriene-metal tricarbonyl complexes C7H8M(CO)3 (M = Cr and W); (c) The 1,3,5-cyclo-octatriene complex C8H10W(CO)3; (d) The cyclooctatetraene–metal tricarbonyl complexes C8H8M(CO)3 (M=Cr or Fe); (e) The 1,5-cyclooctadiene–metal tetracarbonyl complexes C8H12M(CO)4 (M = Mo or W); (f) The tungsten tetracarbonyl complexes of bicyclo[2,2,1] heptadiene and dicyclopentadiene; (g) The 1,3-cyclohexadiene complexes (C6H8)2M(CO)2 (M = Mo or W); (h) The cycloheptadienol complex (C7H9OH)Fe(CO)3; (i) The methyl vinyl ketone complexes (CH3COCH = CH2)3M (M = Mo or W); (j) A product of composition C12H16Fe(CO)2 obtained from allene dimer and Fe3(CO)12. The following fragmentation processes of particular interest were observed: (a) The facile dehydrogenation of ions containing the π-bonded 1,3,5-cyclooctatriene, 1,5-cyclooctadiene, and 1,3-cyclohexadiene ligands with two adjacent CH2 groups; (b) Elimination of neutral C5H6 fragments from tungsten carbonyl ions containing π-bonded bicyclo[2,2,1] heptadiene or dicyclopentadiene ligands; (c) Facile dehydration of iron carbonyl ions with π-bonded cycloheptadienol.
TL;DR: In this article, the interferences encountered in determining rhodium in aqueous solutions by atomic absorption spectrometry was described, and the optimum excitation parameters and the precision of replicate analyses were presented.
Abstract: A study of the interferences encountered in determining rhodium in aqueous solutions by atomic absorption spectrometry is described. In this study, solutions containing rhodium and varying concentrations of a number of the more common elements and acids were aspirated into air–acetylene and nitrous oxide–acetylene flames. It was found that very serious interferences were encountered with the air–acetylene flame, while the nitrous oxide–acetylene flame was essentially free from such interferences. Optimum excitation parameters and the precision of replicate analyses are presented.
TL;DR: The application of molecular rotational resonance (MRR) spectroscopy to the area of molecular structure determinations has been summarized in a number of recent review articles as discussed by the authors, and two developments that offer the promise of expanding the applicability of MRR spectroscopes have been described.
Abstract: A number of recent review articles have summarized the application of Molecular Rotational Resonance (MRR) spectroscopy to the area of molecular structure determinations and described how these applications have applied to chemistry. This article will briefly review this established area of MRR spectroscopy and describe two developments that offer the promise of expanding the applicability of MRR spectroscopy. The first development was the observation that some large molecules (by MRR standards) give a series of relatively intense, equally spaced bands that can be quickly recorded and assigned. The other development has been in the theory, procedures, and instrumentation required for accurate intensity measurements. These two developments, examples of each, and the implication of each for use by chemists, as well as molecular structure determinations, will be discussed. Spectrometers that are being used for studies in this established area and the two newer areas will be described in the Appendix.
TL;DR: A recording system and computer can be used for the complete spectrochemical analysis of photographed spectra as mentioned in this paper, where transmission values, taken at equal intervals of travel along the spectrum are transferred to magnetic tape with high precision and high speed.
Abstract: A recording system and computer can be used for the complete spectrochemical analysis of photographed spectra. Transmission values, taken at equal intervals of travel along the spectrum are transferred to magnetic tape with high precision, high speed, and in a form suitable for computer processing. This processing may include wavelength determination, line identification, and plate calibration.
TL;DR: In this article, the construction and use of a photomultiplier-tube direct-reading polychromator for emission spectroscopy is described for application to measurement of spectral line intensities from plumes generated by a ruby laser microprobe.
Abstract: Construction and use of a photomultiplier-tube direct-reading polychromator for emission spectroscopy is described for application to measurement of spectral line intensities from plumes generated by a ruby laser microprobe Simultaneous correction for background adjacent to each spectral line measured is provided Advantages include capability of external precision alignment and the use of optically and electronically matched components for recording the line and background intensities Although the unit is adaptable to commercial spectrographs, the polychromator constructed was made to fit a Czerny-Turner, f/63, emission spectrograph (Jarrell-Ash Co, Waltham, Mass) which had been designed for photographic recording
TL;DR: In this paper, the authors report the results of some investigations into variations in the arc current, electrode shapes and arc gaps on the electrode, and excitation conditions in arc system.
Abstract: This paper reports the results of some investigations into variations in the arc current, electrode shapes and arc gaps on the electrode, and excitation conditions in the arc system. The results obtained enable an analyst to predict the effects of varying these parameters on the conditions in the arc system. Arising from these investigations a new electrode has been designed which gives virtually constant anode temperatures throughout the lifetime of the burn.
TL;DR: The mass spectra of the following fluorocarbon derivatives of transition metals have been investigated: (a) perfluoroalkyl derivatives Rf Mo(CO)3C5H5 (Rf=CF3 and C3F7); (b) perffluoroacyl derivatives CF3COM (CO) 3C5h5 (M = Mo and W), C3f7COM ( CO) 3c5h 5 (M= Mo andW); and (c) the perfluoraryl derivatives C4F4 and CH3CN fragments
Abstract: The mass spectra of the following fluorocarbon derivatives of transition metals have been investigated: (a) the perfluoroalkyl derivatives Rf Mo(CO)3C5H5 (Rf=CF3 and C3F7); (b) the perfluoroacyl derivatives CF3COM (CO)3C5H5 (M = Mo and W), C3F7COM (CO)3C5H5 (M = Mo and W), and C3F7COFe(CO)2C5H5; (c) the perfluoraryl derivatives RfFe(CO)2C5H5 (Rf =C6F5, p-HC6F4, 3, 4-H2C6F3, and p-CF3F4); (d) the hexafluorobutyne derivatives [(CF3)2C2]3 MNCCH3 (M = Mo and W); and (e) the bis (trifluoromethyl)tetramethylbicyclo-[2.2,2] octatriene complexes C14H14F5Fe (CO)3 and C5H5CoC14H14F6. Unusual features observed in these mass spectra include the following: (a) Evidence for elimination of the neutral metal fluoride fragments FeF2 and C5H5CoF; (b) evidence for the elimination of neutral HF and CF2 fragments; (c) evidence for the elimination of a bridge in the bicyclo [2,2,2] octatriene derivatives; (d) decarbonylation of RfCOMo(CO)3C5H5 compounds, but not their tungsten analogs, in the mass spectrometer; and (e) evidence for the eliminations of C4F4 and CH3CN fragments in the mass spectra of the [(CF3)2C2]3MNCCH2 complexes.
TL;DR: The practical and theoretical aspects of infrared spectroscopy of molecules and molecular fragments within matrices at low temperatures are discussed in detail in this article, including materials used for matrices, the history of the matrix-isolation method of preparation of matrices and mathematical models.
Abstract: The practical and theoretical aspects of infrared spectroscopy of molecules and molecular fragments within matrices at low temperatures are discussed in detail. The following subjects are included in this discussion: the materials used for matrices, the history of the matrix-isolation method of preparation of matrices, unique features of the MIM, problems of the MIM, applications of the MIM, and mathematical models. This paper also discusses pressure and liquid-induced infrared spectra at low temperatures.
TL;DR: A great deal of research has been conducted on the infrared spectra of pure molecules at low temperatures as discussed by the authors, but only a limited amount of information can be acquired on molecules in the liquid, amorphous, and crystalline states.
Abstract: A great deal of research has been conducted on the infrared spectra of pure molecules at low temperatures Only a limited amount of information can be acquired on molecules in the liquid, amorphous, and crystalline states The theories describing the liquid and amorphous states are not yet completely adequate, whereas the theories describing the gaseous and crystalline states appear to be well established The value of lowering the temperature of molecules appears to be that of simplifying their spectra by increasing the order of the system
TL;DR: In this article, the infrared spectra of trifluoroamine oxide and its 15N analogue have been measured from 4000 to 260 cm−1, and the frequency assignment of the remaining fundamental v5(e) to a band system appearing as a shoulder, about 558 cm− 1, on the intense v3(a1) fundamental has been carried out.
Abstract: The infrared spectra of trifluoroamine oxide and its 15N analogue have been measured from 4000 to 260 cm−1. Fundamental frequency assignments (based upon C3v symmetry) made from the 14N spectrum are: v1(a1) = 1689, v2(a1)= 740, v3 (a1) = 528, v4(e) = 880, and v6(e) = 398 cm−1. Normal coordinate calculations support the assignment of the remaining fundamental v5(e) to a band system appearing as a shoulder, about 558 cm−1, on the intense v3(a1) fundamental.
TL;DR: In this paper, the features, problems, and capabilities of applied Auger and photoelectron spectroscopy have been characterized and discussed. But the results are limited to a single image.
Abstract: Various possibilities of Auger and photoelectron spectroscopy as an analytical technique are discussed. In some applications simple electrostatic analyzers with coarse resolution may suffice and even be preferable. Typical spectra obtained with a hemispherical electrostatic analyzer of 0.6% energy resolution are presented and discussed. Such factors as sample thickness, sample potential, surface contamination, and incident angle of the exciting x rays have been found to affect the quality and character of the observed spectra. These results characterize some of the features, problems, and capabilities of applied Auger and photoelectron spectroscopy.
TL;DR: Special “multi-cloistered” NMR cells have been developed to simplify analyses of stereoisomers and other compounds whose NMR spectra exhibit very slight differences in chemical shifts.
Abstract: Special “multi-cloistered” NMR cells have been developed to simplify analyses of stereoisomers and other compounds whose NMR spectra exhibit very slight differences in chemical shifts. They are also applied in studies involving solvent effects.
TL;DR: In this paper, performance data for several elements determined by atomic-absorption flame photometry with the use of a high sensitivity nitrous oxide-acetylene burner is presented and the effect of gas mixtures, feeding rate, and the height of reaction zone on the sensitivities achieved are presented.
Abstract: Performance data are presented for several elements determined by atomic-absorption flame photometry with the use of a high sensitivity nitrous oxide–acetylene burner. Utilizing the specific advantages of this flame, the effect of gas mixtures, feeding rate, and the height of reaction zone on the sensitivities achieved are presented. Flame profiles of several elements studied will be discussed with emphasis on using multiple-pass optics for increased sensitivities. Information will be presented on the problems of this type of flame. Results are presented in terms of the precision and accuracy of routine determinations under selected optimum system conditions and will be discussed.
TL;DR: In this article, the advantages of using a high current dc arc for the emission spectrographic analysis of ashed biological materials are presented, and the method described utilizes 5-10 mg of ash per analysis and provides detection limits between 1 and 50 parts per billion (on the original dry weight basis) for a large number of elements.
Abstract: The advantages that can be realized through the use of a high current dc arc for the emission spectrographic analysis of ashed biological materials are presented. The method described utilizes 5–10 mg of ash per analysis and provides detection limits between 1 and 50 parts per billion (on the original dry weight basis) for a large number of elements. The precision estimates of the method, based on four replicate analyses, are generally better than ±20% and comparative analyses suggest that the accuracies are within these limits. Data is presented which supports the possibility of using a single analytical curve for several different types of ashed biological materials.
TL;DR: In this paper, radiofrequency gas discharge excitation was applied to traces of silver plated onto a filament and subsequently evaporated into a stream of helium, achieving sensitivity of approximately 2x10−2 ng and a coefficient of variation of about 7%.
Abstract: Radio-frequency gas discharge excitation was applied to traces of silver plated onto a filament and subsequently evaporated into a stream of helium. Sensitivity of approximately 2x10−2 ng and a coefficient of variation of about 7% were achieved. The optimization of operating parameters and the effect of copper upon silver emission were also studied.
TL;DR: In this article, a review is presented on vuv spectroscopy, discussing the optics necessary, instrumentation used in absorption and emission vuv, and measurement of wavelength and intensities.
Abstract: A review is presented on vuv spectroscopy, discussing the optics necessary, instrumentation used in absorption and emission vuv, and measurement of wavelength and intensities. Finally, several applications of the technique of interest to the chemist are presented.
TL;DR: In this paper, the Cauchy function, the Gaussian function, and two combinations of these were compared with nine published equations for the shape of a maximum and six of them were recommended as superior.
Abstract: Accurate values for the location of absorption maxima are important in qualitative analysis by spectrophotometry and for theoretical calculations. Accuracy should increase with sharpness of curvature. For instruments recording linearly in one of three ordinates (T, A, or logA), experience shows that optimum peak sharpness occurs respectively at intermediate transmittance and high absorbance, but independent of logA. Using an empirical equation for the shape of a maximum, the curvature is measured by the second derivative, which can be maximized by inspection or by taking the derivative of this with respect to the ordinate, equating to zero, and solving. When nine published equations are put into the three ordinate forms and differentiated, six give results consistent with experience. On the basis of this result and other factors, four of the equations are recommended as superior, namely the Cauchy function, the Gaussian function, and two combinations of these. Comparison of numerical values for curvatures with the three ordinates predict accuracy to be about equal at T=37%, A=0.43, and any value of logA, but greatest for A linear if A is increased.
TL;DR: In this paper, the importance of the correct polymer absorptivities for determining the microstructures of polybutadienes and polyisoprenes, particularly when one component is present in large amount, is shown.
Abstract: The importance of the correct polymer absorptivities for determining the microstructures of polybutadienes and polyisoprenes, particularly when one component is present in large amount, is shown. A method is described for determining both the major and minor polymer absorptivities and an application to the analyses of butadiene–isoprene copolymers is given. The absorptivities of cis- and trans-C(CH3)=CH at 890 cm−1, cis- and trans-C(CH3)=CH at 1155 cm−1 and 1130 cm−1, and of cis-CH=CH at 967 cm−1 are discussed.
TL;DR: The potentialities of resonance spectroscopy are examined and instrument systems utilizing resonance methods are described in this article, where sources and sampling devices are given special attention, as well as their detection limits and their applicability to analysis.
Abstract: Atomic absorption spectroscopy is reviewed especially as to the effect of developments in the past few years on analytical applications. Sources and sampling devices are given special attention. Atomic absorption, flame emission, and atomic fluorescence are compared as to their detection limits and their applicability to analysis. It is shown that the three methods are in many ways complementary rather than competing. The potentialities of resonance spectroscopy are examined and instrument systems utilizing resonance methods are described.