High-resolution FTIR spectrum of the ν5 band of 1,1-difluoroethylene around 550 cm−1

Infrared Spectra of12CF2═12CH2and12CF2═13CH2, Quantum-Chemical Calculations of Anharmonicity, and Analyses of Resonances

“…A 3.7 m gas chromatography column containing dibutylphthalate on Chromosorb at -28 °C was found to give a useful separation of 11DFE from TFE with the latter eluting first. However, some H 2 13 Cd 13 CH 2 , c-C 3 F 6 , and CO 2 remained in the 11DFE-2-13 C 1 sample. CO 2 was removed by distillation through a column containing Ascarite (Thomas Scientific).…”

“…e From ν 6 + ν 9 ) 1660.2, with x 6,9 ) -0.2 cm -1 . f From the 12 C/ 13 C change in 2ν 12 (LA). g From value in gas assuming same phase shift as in 12 C. FR polyad for a given fundamental band could be identified experimentally and the deperturbed values of the overtone and combination levels were available, the deperturbed value of the fundamental level follows directly from use of the property of the determinant that the trace is constant.…”

“…The presence of FR is the obstacle here, however. The ν 3 FR calculations described below lead to a doubtful assignment of ν 3 + ν 11 to a very weak peak in the LA spectrum of the 13 C species at 2137.2 cm -1 , provided that the more negative value of x 3,11 of -16.7 cm -1 from the mcct model is employed (Table S4).…”

“…[24][25][26] Experimental Section Synthesis. 11DFE-2- 13 C 1 was made by photochemical reaction of ketene-2- 13 C 1 with excess tetrafluoroethylene (TFE, old tank from Peninsular Chem Research, Gainesville, FL) with medium pressure mercury lamp excitation in a Pyrex flask. 29 Ketene-2- 13 C 1 was the product of flash vacuum pyrolysis of acetic anhydride-2,2′- 13 C 2 (Cambridge Isotope Laboratory) in a carbonized quartz tube at 585 °C.…”

“…Liquid cells with path lengths of 1, 4, and 7 cm were were equipped with wedged windows of silicon, zinc selenide, or CaF 2 . Mole fractions of solute in the argon solutions varied from 2 × 10 -5 to 4.5 × 10 -3 for the 12 C species and 1.4 × 10 -5 to 3.9 × 10 -4 for the 13 C form, with the reduced range for the latter reflecting the smaller sample size available. No possible solute dimer bands were identified.…”