Synthesis and Vibrational Spectroscopy of 1,1,2,2-Tetrafluoroethane and Its ¹³C₂ and d₂ Isotopomers

Abstract

The 13 C 2 and d 2 isotopomers of 1,1,2,2-tetrafluoroethane (TFEA) have been synthesized. Raman spectra of these new species have been recorded, and infrared spectra of all three isotopomers, including some regions with high-resolution at -100°C, have also been recorded. Guided by recently published calculations of frequencies and infrared intensities and the new spectra, we have revised the previous assignments of fundamentals for the two rotamers of the normal species of TFEA. Assignments of the fundamentals for both rotamers of the 13 C 2 and d 2 isotopomers are proposed. The anti rotamer is the more abundant species in the gas phase and, to a lesser extent, in the liquid phase and the only species in the crystal phase. Thus, the assignments of the anti rotamer of all three isotopic species are complete and supported by isotope product rules, but the assignments for the gauche rotamers are incomplete. Estimates of the missing frequencies for the gauche rotamer of the normal species are supplied.

Microscale Preparation of Isotopically Enriched 37ClHC˭CHF

“…During fluorination in a closed reactor, the presence of the most volatile product 3 was periodically checked by gas-phase IR spectroscopy. [11] After separation, the more abundant and pure fluorinated ethane 3 was reacted with zinc in absolute ethanol to afford a cis-trans mixture of BrHC5 5CHF (4). Traces of vinyl fluoride and acetylene were identified by IR spectroscopy [12,13] in the raw 4 into the reaction vessel.…”

Electron Driven Reactions in Tetrafluoroethane: Positive and Negative Ion Formation

“…The photofragmentation dynamics of R134a was studied using threshold photoelectron−photoion coincidence (TPEPICO) spectroscopy. 7,17,18 Additionally, the vibrational spectra and a conformation analysis of R134a were reported by making use of infrared 19 and Raman spectroscopic techniques 19−21 as well as by ab initio calculations. 22 Recently, the dissociative channels and electronic properties of ionized and excited states of R134a were investigated by computational chemistry.…”

“…Consequently, detailed studies on the R134a molecule have been drawing the attention of experimental and theoretical researchers. The photofragmentation dynamics of R134a was studied using threshold photoelectron–photoion coincidence (TPEPICO) spectroscopy. ,, Additionally, the vibrational spectra and a conformation analysis of R134a were reported by making use of infrared and Raman spectroscopic techniques − as well as by ab initio calculations …”

Complete Structure of anti-1,1,2,2-Tetrafluoroethane by High-Resolution Infrared Spectroscopy

“…These species were prepared by brominating commercially available acetylene-d 2 and acetylene-13 C 2 to give the tetrabromoethanes, which were reacted with AgF 2 , as described fully elsewhere. 9 The medium-resolution infrared and Raman spectra of TFEA and its isotopomers were fully investigated as a preliminary to the high-resolution investigation. 9 This study led to some revisions in the assignments of the normal modes of the rotamers of TFEA as well as to first assignments for the fundamentals of the isotopomers.…”

“…9 The medium-resolution infrared and Raman spectra of TFEA and its isotopomers were fully investigated as a preliminary to the high-resolution investigation. 9 This study led to some revisions in the assignments of the normal modes of the rotamers of TFEA as well as to first assignments for the fundamentals of the isotopomers.…”