Maxwell Goldblatt

Potential Constants of Iron Pentacarbonyl from Vibrational Spectra of Isotopic Species

The vibrational spectra of Fe(12C16O)5, Fe(13C16O)5, and Fe(12C18O)5 have been observed. Most of the fundamentals have been assigned, with some changes from earlier results in the literature. Potential constants have been calculated by constraining many of the interaction constants to values estimated from analogous constants of the hexacarbonyls. The results indicate that the axial CO bonds are stronger than the equatorial CO bonds. This implies that the axial MC bonds are weaker than the equatorial MC bonds, though the calculated MC potential constants are not significantly different.

Force Constants of Nickel Carbonyl from Vibrational Spectra of Isotopic Species

The infrared spectra of gaseous Ni(13CO)4 and Ni(C18O)4 and the infrared and Raman spectra of CCl4 solutions of these isotopic molecules were recorded. General quadratic valence force constants have been calculated from the frequencies of the normal species and the two isotopic species. The resulting force constant solution is similar to that obtained previously assuming a pi electron interaction potential function. These results put the force constants of metal carbonyls on a firmer basis.

Determination of deuterated methanes for use as atmospheric tracers

The deuterated methanes, /sup 13/CD/sub 4/ and /sup 12/CD/sub 4/, are useful as tracers for long-range (>500-km) atmospheric transport. They are easily synthesized and released. Sampling is accomplished by collecting about 330 l of air and chromatographically separating the methane fraction, which is then analyzed by mass spectrometry for the /sup 13/CD/sub 4///sup 12/CH/sub 4/ and /sup 12/CD/sub 4///sup 12/CH/sub 4/ ratios. Detection limits in air are about 7 x 10/sup -16/ STP mol m/sup -3/ for /sup 13/CD/sub 4/ and 2 x 10/sup -15/ STP mol m/sup -3/ for /sup 12/CD/sub 4/. 11 refs., 5 figs.

Infrared spectrum and molecular constants of CT4

Abstract The bands, ν 3 , ν 4 , and 2 ν 3 of CT 4 have been observed. The ν CH band of CHT 3 was observed also. An analysis of the band ν 3 of CT 4 yields ν 3 = 1937.0 cm −1 and ζ 3 = 0.252. The data on CT 4 was combined with data in the literature of CH 4 and CD 4 to calculate average valence force constants for the methanes.

Analysis of the Fourier transform spectra of 12C17O2 and 12C17O18O: The ν2 (15 μm) region☆

Abstract The vibration-rotation spectra of the ν 2 fundamental of 12 C 17 O 2 and 12 C 17 O 18 O have been obtained by Fourier transform spectroscopy at 0.05 cm −1 resolution. The data were fitted by a least-squares routine to obtain a number of the molecular constants. The band center for 12 C 17 O 2 lies at 662.0716 cm −1 while that for 12 C 17 O 18 O is at 659.7057 cm −1 . The difference bands ν 1 - ν 2 have also been observed for the two molecular species.

Ionization Constants of T2O and D2O at 25° from Cell emf's. Interpretation of the Hydrogen Isotope Effects in emf's

The ionization constants of T2O and D2O were determined to be 6.1 × 10−16 and 1.43 × 10−15 at 25°, corresponding to K(H2O) / K(T2O) = 16.4 and K(H2O) / K(D2O) = 7.1 (concentrations in aquamolalities m′, moles of solute per 55.51 moles of isotopic water). Emfs were measured at 25° with X = H, D, and T for cells of the types: Pt–X2(p) | NaOX(m2′)+NaCl(m3′) | AgCl–Ag and Pt–X2(p) | XCl(m1′) | AgCl–Ag; m1′ = m2′ = m3′ = 0.1. The isotope differences [E°(isotope) − E° (H2O)] in the alkaline cell are 45.8 ± 0.5 mV for D2O and 65.4 ± 0.3 mV for T2O. In the acid cell the differences are − 4.4 ± 0.1 mV for D2O and − 6.4 ± 0.2 mV for T2O. Published data on the H2O–D2O emf isotope effects from 5° to 50° in alkaline and acid cells are correlated with spectral and structural information by methods similar to those used in the treatment of vapor‐pressure isotope effects. These methods and the H2O–D2O data are used to predict H2O–T2O isotope effects in emfs and a value of K(H2O) / K(T2O) which agree satisfactorily with...

Near infrared absorption spectra of oxygen-18 enriched carbon dioxide

Abstract The near infrared absorption spectra of 12C18O2 have been recorded using a vacuum prism-grating spectrograph with a resolution of about 0.03 cm−1. A one-meter absorption path was used with pressures ranging from 4 mm Hg to 10 cm Hg. The vibrational transitions (1001,0201)I-0000, (1001,0201)II-0000, (2001,0401)I-0000, (2001,0401)II-0000, (2001,0401)III-0000, and their associated “hot” bands were observed and the structure has been analyzed to determine the vibrational energy levels and relevant rotational constants.

INFRARED SPECTRUM AND MOLECULAR CONSTANTS OF GASEOUS TRITIUM FLUORIDE

Abstract The vibration-rotation lines of ν 1←0 and ν 2←0 for tritium fluoride ( g ) have been observed with ≈1 cm −1 and ≈2.5 cm −1 resolution, respectively. Molecular constants were calculated from the observed frequencies. Within the accuracy of measurement the observed constants agree with those previously reported ( 1 ) for hydrogen fluoride ( g ). The “least squares” values of the molecular constants in cm −1 are: ν 1←0 = 2443.86, ν 2←0 = 4823.8, ω e = 2508.5, x e ω e = 32.5, B e = 7.69, α e = 0.176, D e = 2.5 × 10 −4 . The bond distance is 0.917 A and the force constant is 9.65 × 10 5 dynes/cm.

Analysis of the Fourier transform spectrum of 13C18O2 in the 4.3- and 16-μm regions☆

Fourier transform spectra have been obtained for 13C18O2 in the regions of ν2 (16 μm) and ν3 (4.3 μm) at a resolution of 0.04 cm−1. From a least-squares fit of the P- and R-branch lines for the transitions, values have been calculated for the rotational constants B, the centrifugal distortion constants D, and the band origins. Based on the derived constants, the calculated wavenumbers for the P and R lines of both the 0110-0000 and 0001-0000 transitions agree with the observed positions within ±0.003 cm−1. We have also observed the difference bands ν1-ν2 and the hot bands (ν3 + ν2) − ν2. From an analysis of these transitions we have determined values for the l-doubling constants for ν2 and the location of the inactive fundamental ν1.

Vibration rotation bands of C2T2: Part I. ν3☆

Abstract C 2 T 2 has been prepared, and its infrared absorption spectrum has been examined under high resolution. Rotational analysis of the ν 3 fundamental has been made, and a value B 0 = 0.6621 5 ± 0.00020 cm −1 obtained. Other bands observed include ν 5 , ν 4 + ν 5 and possibly ν 2 + ν 5 , ν 3 + ν 4 − ν 4 and ν 2 - ν 5 .