Erratum: Resonant and Near Resonant Vibrational

Erratum: Resonant and Near Resonant Vibrational—Vibrational Energy Transfer between Molecules in Collisions Donald Rapp and Paula EnglanderGolden Citation: J. Chem. Phys. 40, 3120 (1964); doi: 10.1063/1.1724961 View online: http://dx.doi.org/10.1063/1.1724961 View Table of Contents: http://jcp.aip.org/resource/1/JCPSA6/v40/i10 Published by the AIP Publishing LLC.

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3120

LETTERS TO THE EDITOR

in water or for a variation in the degree of hydrogen bonding as ions are added.' 1 K. Buijs and G. R. Chpppin, J. Chern. Phys. 39, 2035, 2042 (1963) . 2 P. C. Cross, J. Burnham, and P. A. Leighton, J. Am. Chern. Soc. 59, 1134 (1937). 3 R. D. Waldron, J. Chern. Phys. 26, 809 (1957). 'R. E. Weston, Spectrochim. Acta 18,1257 (1962).

Assignment of the Near-Infrared Bands of Water and Ionic Solutions K.

BUIJS

Centre d'Etude de l'Energie Nucleaire Mol-Donk, Belgium AND

G. R.

CHOPPIN

Department of Chemistry, Florida State University Tallahassee, Florida

(Received 27 January 1964)

N his comment on our papersl dealing with the nearinfrared spectrum of water and ionic solutions, Hornig2 points out that in the fundamental absorption bands of H 20, HDO, and D 20, no evidence has been found for a distinction between species of water molecules with different degrees of hydrogen bonding. In the region of the stretching vibrations a Fermi resonance between Vl, and 2V2 for H 20 and D 20 is assumed in order to explain the observed spectrum. Recently, however, the occurrence of Fermi resonance in this case has been seriously questioned by Lauwers and van der Kelen. 3 In the stretching bands of HDO where no Fermi resonance occurs, very little asymmetry is found both in the Raman3 and infrared4 spectra. This band asymmetry indeed is insufficient to form a basis for the evaluation of a model containing different species of water molecules. On the other hand, this small amount of asymmetry is not, in our opinion, proof of the nonexistence of these species. This is even more true since the system H 20+D 20 can be expected to be somewhat more complex than the pure components. However, the following arguments can be put forward in favor of our interpretation of the near-infrared spectra, assuming even that a Fermi resonance occurs between Vl and 2V2. (1) Our analysis for the assignment of the 8620-K band suggests that it originates from the Vl +V2+V3 vibration of some species of water molecules, even if this were the only species present. The conclusion from this analysis that Vl for this same species occurs at approximately 3600 K makes it highly improbable that this mode is in Fermi resonance with 2V2(2X 1645 K). A Fermi resonance can only be explained by ascribing it to the Vl mode of another H 20 species (probably Sl)' This may be taken as indirect evidence that

I

for the evaluation of the fundamental stretching bands, different species of water molecules also must be considered. (2) A Fermi resonance in the fundamental region usually returns in a number of overtones and combinations. However, resonance between Vl+V2+V3 and V3+3V2 (both of symmetry species B 1 ) as an explanation for the behavior of the 8620- and 8330-K bands would require a limiting value of unity for the intensity ratios. This condition is not fulfilled considering not only the absorption coefficients at the peak wavelengths but also the fact that the 8330-K band is broader than the 8620-K band. (3) The frequency changes associated with the intensity changes are negligible suggesting strongly that the spectral changes originate from changes in concentrations in a mixture of species rather than from changes in Fermi resonance. The assignment of the 8000-K band of ice which appears rather strongly in the solutions of, e.g., LaCla seems justified also by the frequency shift shown by other overtones and combination bands in the spectrum of ice. As a result of all these considerations we must conclude that the existence of different species of water molecules offers the most plausible explanation for the observed phenomena. 1 K. Buijs and G. R. Choppin, J. Chern. Phys. 39, 2035, 2042 (1963) . 2 D. F. Hornig, J. Chern. Phys. 40, 3119 (1964) (preceding Letter). 3 H. A. Lauwers and G. P. van der Kelen, Bull. Soc. Chirn. Belg. 72, 477 (1963). 4 R. E. Weston, Spectrochirn. Acta 18, 1257 (1962). 6 R. D. Waldron, J. Chern. Phys. 26, 809 (1957).

Erratum: Resonant and Near Resonant Vibrational-Vibrational Energy Transfer between Molecules in Collisions DONALD RAPP AND PAULA ENGLANDER-GOLDEN

Lockheed Missiles and Space Company, Palo Alto, California

[J. Chern. Phys. 40, 573 (1964)]

SERIOUS arithmetic error was made in the illustrative example just below Eg. The A transition probability proper expression for the (16).

1~01

in N 2-N 2 collisions should read PI0-0l

= sin2 (5.6X 1O-7vo),

not sin2 (1.5 X 1O-5vo ) . This reduces the predicted transition probability to considerably lower values than that given in the original paper. Figure 1 shows the proper result. Since the probabilities are low enough at room temperature, we can use the first-order perturbation


3121

LETTERS TO THE EDITOR

Erratum: Transfer of Triplet Excitation Energy in Benzophenone Crystals 0.8

U. Chern. Phys. 39, 3153 (1963)] ROBIN M. HOCHSTRASSER John Harrison Laboratory of Chemistry, University of Pennsylvania Philadelphia, Pennsylvania

0.6

~

0:-04 02 o.~~~~~~~--~----~~~~

0.2

04

0.6 0.8 I

2

v (106 CwSEC)

FIG. 1. The 10->01 transition probability in N2-N2 collisions calculated as a function of velocity from Eq. (16).

limit of Eq. (14) by simply replacing the sine of an argument by the argument. We then find that PIO-+Ol"'7I'2fi1}V02 (V 10.01') 2/16'h,2k 2.

HE author overlooked reference to the extremely useful paper by J. P. Cadas, C. Courpron, R. Lochet, and A. Rousset [Compt. Rend. 254, 2490 (1962)] in which a study of the long-lived portion of the luminescence from eutectic mixtures of naphthalene and benzophenone is presented. This was brought to the author's attention through the recent review of triplet-triplet energy transfer processes by V. A. Ermolaev {Soviet Phys.-Uspekhi, 6,333 (1963) CUsp. Fiz. Nauk 80, 3 (1963)]1.

T

If we average this over the thermal distribution given in Eq. (30) of Ref. 1,

dn(vo) = (m/kT)vo exp( -mv02/2kT)dvo,

Notes

we find

(P 11).. 01 )"'rm (V 10.01') 2kT/8'h,2k 2• Thus, we predict

(P 10-+ 01 )= 3.7X 10-6 T.

Observation of FeO in Absorption by Flash Heating and Kinetic Spectroscopy ARNOLD

and the average probability at room temperature is about 10-3• The same error was made in the near resonant case, and the equation after Eq. (19) should be similarly amended. The correction factor for the nonresonance remains the same. The result of applying Eq. (19) to a series of processes is then in fair agreement with the results of Call ear [Discussions Faraday Soc. 33, 28 (1963)]. We are grateful to Dr. Fred H. Mies for bringing this error to our notice. Note that the exponent -5 in the sech function appearing in the equation below Eq. (19) should be +5. Also, the symbol c!n below Fig. 1 should be Cjn.

Erratum: Potential Energy Surfaces for the H3+ Molecule-Ion [J. Chern. Phys. 40, 603 (1964») HAROLD CONROY

Mellon Institute, Pittsburgh, Pennsylvania

HE second sentence of the second paragraph should read: For one electron, with nuclei a, b, and c, bearing charges Za, Zb, and Zc, xn=AnO'-a exp[ -'YP+ ('Y-e)O'-I] where 0'-1= (r 2+s2 )l, 'YP= 2:aZara, 'Y= 2:aZa, e= (_2E)l, and a='Y/e-1, with r the radial distance to the center of positive charge and s a constant.

T

M.

BASS

National Bureau of Standards, Washington, D. C. N. A. KUEBLER

Bell Telephone Laboratories, Murry Hill, New Jersey AND

L. S.

NELSON

Sandia Laboratory, Albuquerque, New Mexico (Received 2 January 1964)

HE emission spectrum of the diatomic oxide, FeO, has been studied for a number of years. 1- 8 In extending these studies, several new ways to produce the spectrum in absorption have been examined recently. We report here on the use of flash heating and kinetic spectroscopy9 for the excitation of the orange system A and B bands of FeO in absorption, and a diffuse absorption feature in the 2410-2430 1 region during the direct reaction of metallic iron with gaseous oxygen. In flash photolysis experiments with ferroceneoxygen and iron pentacarbonyl used as additives in n-heptane-amyl nitrite-oxygen explosions, Callear and Norrish 6 have observed the orange bands both in emission and absorption, several strong FeO bands in emission in the 8000-10 000-1 region, several unidentified features, and a new, rather diffuse feature in emission and absorption lying between 2410 and 2430 1 that has been attributed on chemical grounds to FeO. The flash heating technique uses an intense light pulse from a capacitor discharge lamp to induce rapid high-temperature reactions at the surface of a solid of

T
