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The KnowledgeBank at OSU (74.956 recursos)

Knowledge Bank contains collections of presentations, publications and reports related to Ohio State University.

Abstracts of OSU International Symposium on Molecular Spectroscopy 1960-1969

Mostrando recursos 1 - 20 de 1.956

  1. THE MICROWAVE SPECTRUM OF NORMAL PROPYL IODIDE.

    Sarachman, T. N.
    The microwave spectrum of normal propyl iodide has been studied in the spectral region from 18 GHz to 36 GHz. The observed spectrum is accounted for by the presence of two rotational isomers, the gauche and trans forms of the molecule. Because of the great mass of the iodine atom, both rotational isomers are very nearly symmetric prolate rotors. The trans form spectrum consists of the $J \rightarrow J +1, \Delta K=0 R^{a}$ transitions, of which only the $K = 1$ lines are resolved; the gauche spectrum exhibits in addition to these $R^{a}$ transitions a series of $Q^{b}$ transitions $J_{1,J-1}\rightarrow...

  2. MICROWAVE SPECTRUM OF METHYLCYCLOPROPYL KETONE.

    Lee, P. L.; Schwendeman, R. H.
    The microwave spectrum of methylcyclopropyl ketone has been examined in the 8-36 GHz region. A very rich spectrum has been observed in which b-type transitions have been assigned for a species with the carbonyl group cis to the cyclopropyl ring. The transitions are split into doublets by the internal rotation of the methyl group. Transitions have been assigned for species in the first three excited states of the torsional motion in which the acetyl group rotates with respect to the cyclopropane ring. The rotational constants for the ground state are $A = 7204.33 MHz, B = 2630.88 MHz$, and $C...

  3. THE MICROWAVE SPECTRUM OF GLYCOLALDEHYDE.

    Simons, Margaret A.; Woods, R. C.
    Glycolaldehyde $(CHOCH_{2}OH)$ has been found to exist in an intramolecularly hydrogen bonded ring structure with a plane of symmetry. A large number of transitions have been assigned in the frequency range 8-18GHz for the normal species and for $CHOCH_{2}OD$. The rotational constants derived from these data are $A = 18,446.28 MHz, B = 6525.92, C = 4969.23$ for the normal and $A = 17491.15, B = 6499.57, C = 4883.10$ for the deuterated form. Five sets of lines due to excited vibrational states have also been assigned. Preliminary Stark effect measurements indicate $\mu_{a} = 0.50D$ and $\mu_{b} =2.38D$ are the...

  4. COMMENTS ON THE MICROWAVE SPECTRA OF METHYLCHLORO-DIAZIRINE, TRIMETHYLAMINE AND ETHYLENE EPISULFOXIDE.

    Wollrab, James E.
    Ground state rotational spectra of $CH_{3}^{25}CICN_{2}$ and $CH_{3}^{37}CICN_{2}$ have been assigned, and the derived $r_{0}$ structural parameters are: $r(NN)= 1.241 \pm 0.005{\AA}, r(CCl) = 1.743 \pm 0.01{\AA}, r(CC) = 1.498 \pm 0.01{\AA}, \sphericalangle CC-C-Cl = 116.7^{\circ} \pm 1.0^{\circ}, \sphericalangle CCN_{2} = 124.5^{\circ} \pm 1.0^{\circ}$, and $\sphericalangle NCN = 50.2^{\circ} \pm 0.5^{\circ}$. The internal rotation splittings for $CH_{3}^{35}CICN_{2}$ yield a barrier to internal rotation of $1689 \pm 10$ calories mole$^{-1}$. The Cl quadrupole coupling constants (MHz) for $CH_{3}^{35}ClCN_{2}$ are $\chi_{aa} = -66.51, \chi_{bb}=32.91, \chi_{cc}=33.60$ and for $CH_{3}^{37}ClCN_{2}$ are $\chi_{aa}=- 53.07, \chi_{bb} = 26.40, \chi_{cc} = -66.51, \chi_{bb} = 32.91, \chi_{cc} =...

  5. THE MOLECULAR ZEEMAN EFFECT IN $O_{3}, OF_{2}, CH_{3}C^{14}N, CH_{3}^{14}NC, H_{2}CF_{2}, H_{2}C = CF_{2}, cis-HFC = CHF, OCF_{2}, PF_{3}, OPF_{3}, SOF_{2}$, AND $SO_{2}F_{2}$.

    Pochan, J. M.; Blickensderfer, R. P.; Wang, J. H. S.; Stone, R. G.; Flygare, W. H.
    The magnetic properties of the above molecules will be discussed. Both the first-order (H) and second-order ($H^{2}$) Zeeman parameters (molecular g-values and magnetic susceptibility anisotropies) have been measured. The molecular quadrupole moments and other interesting molecular parameters are discussed in light of the molecular electronic structures.

  6. MOLECULAR G-VALUES, MAGNETIC SUSCEPTIBILITIES, AND MOLECULAR QUADRUPOLE MOMENTS IN CYCLOPROPENE, FLUOROBENZENE, FURAN, THIOPHENE, TRIMETHYLENE OXIDE, TRIMETHYLENE SULFIDE, ETHYLENE OXIDE, AND ETHYLENE SULFIDE.

    Benson, R. C.; Tigelaar, H. L.; Sutter, D.; Huttner, W.; Flygare, W. H.
    The molecular Zeeman effect has been observed in the series of ring compounds listed above. Both the first order (H) and second order ($H^{2}$) Zeeman parameters are recorded and listed for the above molecules. The first-order parameters are the molecular magnetic moments or molecular g-values and the second-order parameters are the magnetic susceptibility anisotropies. Combining these experimental parameters gives the molecular quadrupole moments for these molecules. The electronic distributions are discussed as well as the magnetic properties of the rings. The sign of the electric dipole moment of cyclopropene is also obtained.

  7. THE MOLECULAR ZEEMAN EFFECT AND MAGNETIC SUSCEPTIBILITY ANISOTROPIES IN ACETYLENIC MOLECULES.

    Shoemaker, R. L.; Flygare, W. H.
    High-resolution microwave spectroscopy is combined with high magnetic fields (up to 30,000 gauss over a 6 foot length) to yield resolvable first-order (H) and second order $(H^{2})$ Zeeman spectra in a large number of molecules. The magnet and phase locked microwave spectrograph ($2.0-40.0$ gHz) will be described briefly. The molecular Zeeman effect has been observed in fluoroacetylene, methylacetylene, and methyldiacetylene. The molecular g-values and magnetic susceptibility anisotropies are given which lead to the second moment of the electronic charge distribution and molecular quadrupole moments. The magnetic properties of these molecules will be discussed in light of recent work on $CH_{3}CN$...

  8. THE MICROWAVE SPECTRA OF 2-METHYL-1-BUTEN-3-YNE, trans-AND $cis-1,3$-PENTADIENE

    Hsu, S. L.
    The microwave spectra of 2-methyl-1-buten-3-yne, trans-1,3-pentadiene and cis-1,3-pentadiene were all assigned and the methyl group barriers to internal rotation were measured. The results for 2-methyl-1-buten-3-yne are: $A = 9359.58 \pm 0.02 MHz, B \pm 4013.52 \pm 0.01 MHz, C = 2854.80 \pm 0.01 MHz, V_{3} = 2011 \pm 70 cal/mole$. For trans-1,3-pentadiene $A = 28.5 GHz, B = 2161.6 \pm 0.2 MHz, C = 2033.2 \pm 0.2 MHz, V_{3} = 1813 \pm 60$ cal/mole. For cis-1,3-pentadiene: $A = 15.6 GHz, B = 2659.2 \pm 0.1 MHz, C = 2306.1 \pm 0.1 MHz, V_{a} = 750 \pm 50$ cal/mole. The molecular...

  9. SYMMETRY PROPERTIES OF THE INTERNAL COORDINATE SPACE DERIVED FROM ITS METRICAL TENSOR (G MATRIX).

    Dellepiane, G.; Gussoni, M.; Zerbi, Giusepp
    In the present paper it is shown that the G matrix provides directly: 1) the point group to which the molecule belongs (characters of the irreducible representations); 2) the separation into symmetry species of the symmetry coordinates derived, as already discussed$^{1}$ by diagonalization of the G matrix; and 3) the symmetry properties of the potential energy matrix. On the basis of this method a program has been written which, given the G matrix as input, computes the properly factorized G and V. F. F. Z matrices. The method may also be extended to chain molecules.

  10. DISTRIBUTION OF EIGENVALUES AND EIGENVECTORS OF CHAIN MOLECULES CONTAINING RANDOM DEFECTS.

    Gussoni, M.; Dellepiane, G.; Zerhi, G.
    In a previous $work^{1}$ Dean's negative eigenvalue theorem has been used to compute the distribution of eigenvalues of a chain molecule containing randomly distributed mass defects. The method has been extended to conformational $defects^{2}$ and, in the present work, to force constant defects. For a better understanding of the molecular dynamics of the chain, we have also applied the Givens-House-holder's method which allows to obtain the distribution of eigenvectors corresponding to approximate eigenvalues of very large matrices.

  11. MEASUREMENT OF ABSOLUTE INTENSITIES IN MICROWAVE ROTATIONAL SPECTROSCOPY

    Scharpen, Leroy H.; Curl, R. F., Jr.
    A method of calibrating signal strength for the Hewlett-Packard spectrometer by introducing a known modulation index has been devised. The curve of power versus grid voltage for the frequency stabilized backward wave oscillator microwave source is determined. Then a small, known 33.3 kHz square wave voltage is applied to the grid. From the magnitude of this voltage and the power versus grid voltage curve, the modulation index may be calculated and the propertionality constant (overall gain constant) relating signal strength to modulation index determined. The absolute intensities of the lines of several compounds have been measured and compared with theory....

  12. THE INVERTOR: AN EXACTLY SOLUBLE MODEL FOR THE ROTATION-INVERSION PROBLEM OF ETHYLENEIMINE-TYPE MOLECULES.

    Attanasio, A.; Bauder, A.; Günthard, Hs. H.
    Several molecules, mostly amines, are known to show large amplitude internal motions of the inversion type. The prominent feature is normally the tunneling of a hydrogen atom through a potential barrier. The simplified model for such a molecule consists of a rigid frame and a hydrogen atom or a group of atoms which are bound to the frame to move on a circular path between the two equilibrium positions. The classical Hamiltonian of the over-all rotation and inversion is set up and converted to the correct quantum-mechanical Hamiltonian for this model. It is shown that the matrix elements of the...

  13. MICROWAVE SPECTRA OF TORSIONALLY EXCITED STATES OF NITROETHYLENE.

    Nosherger, P.; Bauder, A.; Gonthard, Hs. H.
    Nitroethylene shows a torsional motion of the nitro group with a frequency of $99.5 cm^{-1}$ in the far infrared. In the microwave spectrum, the ground state and five excited torsional states could be measured for the lowest pure rotational transitions. It was already shown that the equilibrium structure is planar. An attempt to explain the variation of the rotational constants and the inertia defect in the different torsional states with the existing theories of Oka and Morino or Lauric and Herschbach failed. The discrepancies mainly arise from the neglect of anharmonic terms in the torsional motion. However, the application of...

  14. THE MICROWAVE SPECTRUM OF MORPHOLINE.

    Sloan, J. J.; Kewley, R.
    The microwave spectrum of morpholine has been observed within the 8-40 GHz region. The ground vibrational state rotational constants and quadrupole coupling constants for the chair equatorial conformer are (in MHz) for undeuterated morpholine $A = 4924.88, B = 4625.15, C = 2684.25, \chi_{aa} = 2.22, \chi_{bb} = 2.51, \chi_{cc} = -4.73$ and for N-deutero morpholine $A = 4925.39, B = 4399.67, C = 2607.09, \chi_{aa} = 1.92, chi_{bb} = 2.59, \chi_{c} = -4.51$. The dipole moment of this conformer has been determined to be 1.71 D.

  15. MICROWAVE SPECTROSCOPY FROM $8.0-40.0$ GHz OF THE OH- ION IN THE KCI AND NaCl LATTICES AT $1.2^{\circ} K$.

    Scott, R. S.; Flygare, W. H.
    Microwave resonant absorption has been observed in $OH^{-}$-doped KCl and NaCl crystals. Several lines were observed from $8-40$ GHz by using relatively standard spectroscopic techniques. The zero-field spectra obtained here indicate that the $OH^{-}$ ion experiences a strong $C_{4v}$ potential in addition to the expected octahedral crystal field. The $C_{4v}$ potential probably arises from a shift of the $OH^{-}$ center of mass from the lattice site.

  16. HIGH RESOLUTION INFRARED SPECTRA OF SMALL CRYSTALS OF BARIUM AND THALLOUS AZIDE.

    Iqbal, Zafar
    The vibrational spectra of large sized crystals of sodium, potassium and cesium azides have been studied by $Bryant.^{1}$ In the present study, high resolution spectra in the region $4000-200 cm^{-1}$ of single crystals of anhydrous barium azide (dimensions $5.00\times 1.00\times 0.10 mm$) and thallous azide (dimensions $2.50\times 0.70\times 0.014 mm$) have been recorded using a dual Perkin Elmer $6\times$ microsampling attachment with a Perkin Elmer 621 grating spectrophotometer. A large number of bands were observed for barium azide. The selection rules for the internal and lattice vibrations and their combinations were calculated by the ``unit cell'' $method^{2}$ in terms of...

  17. THE INFRARED SPECTRUM OF PRUSSIAN BLUE AND OTHER METAL-IRON CYANIDE COMPOUNDS.

    Wilde, R. E.; Ghosh, S. N.
    The infrared spectra of Prussian blue and compounds of the type $M_{2}[Fe(CN)_{6}$ where $M = Cu, Zn$, Cd have been obtained in the region $33-4000 cm^{-1}$. In addition, Prussian blue has been spectroscopically studied in the temperature range $300^{\circ}K-4^{\circ}K$. Spectra obtained at $300^{\circ} K$ and $77^{\circ}K$ are different in the region of the Fe-C stretching motion. The infrared spectra will be correlated with the x-ray, magnetic susceptibility, and Mossbauer studies in an effort to clarify the structures of the metal-iron cyanide compounds.

  18. INFRARED SPECTRA AND STRUCTURES OF THE NOBLE GASESMETHANE MIXED CRYSTALS.

    Chamberland, A.; Cabana, A.
    The infrared spectra of methane dissolved in the solid gases have been obtained at various concentrations in the range 0.06% to 55%. While at low concentrations the spectra of the three different systems resemble each other closely, at high concentrations the spectra are different. The influence of the molecular concentration on the fine structure of the asymmetric stretching vibration of methane will be discussed in terms of the structure of the mixed solutions.

  19. INFRARED AND RAMAN SPECTRA OF SILANE IN THE CONDENSED PHASES.

    Belzile, R.; Cabana, A.; Fournier, R. P.; Savoie, R.
    The infrared and Raman spectra of silane in its condensed phases have been obtained. The most interesting features are seen on the spectra of the crystal in phase II. The crystal structure is unknown. The spectra will be interpreted in terms of possible site and factor groups.

  20. OPTICAL PHONONS AND PHASE TRANSITION OF THALLOUS IODIDE.

    Lowndes, R. P.; Perry, C. H.
    Far infrared transmittance and reflectance and Raman spectroscopic measurements have been made on polycrstalline thallous iodide in the temperature range $5^{\circ}-550^{\circ}K$. In particular, the spectroscopic investigations have been used to study the 4 molecule/unit cell $D^{17}_{2h}$ (Cmem) orthorhombic structure transition to the $O^{1}_{b}$ (Pm3m) CsCl structure which occurs near $445^{\circ}K$. In the orthorhombic structure one infrared active transverse optic mode and six Raman active modes were observed; group theoretical predictions indicate that there should be three infrared active and six Raman active modes. In the CsCl structure a single infrared transverse optic mode is still found but displaced to much...

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