Structures and Properties of trans‐1,3,3,3‐Tetrafluoro‐ propene (HFO‐1234ze) and 2,3,3,3‐Tetrafluoropropene (HFO‐1234yf) Refrigerants

Abstract

The refrigerant trans-1,3,3,3-tetrafluoropropene (HFO-1234ze) is used as a replacement for former cooling agents that have been phased-out due to their global warming potential or ozone depleting potential. Although it is used on a large scale, only a few vibrational data and no structural data of HFO-1234ze are known. We report structure determinations based on low-temperature single-crystal X-ray diffraction data as well as gas-phase diffraction data of HFO-1234ze and HFO-1234yf (2,3,3,3-tetrafluoropropene). Furthermore, vibrational spectra of HFO-1234ze in all phases are described. The results are discussed together with quantum-chemical calculations on the PBE0/cc-pVTZ level of theory. Combustion experiments of HFO-1234ze show carbonyl difluoride, carbon dioxide and hydrogen fluoride to be the main combustion products.

Studies of RPC detector operation with eco-friendly gas mixtures under irradiation at the CERN Gamma Irradiation Facility

“…Within this gas family, tetrafluoropropene (C 3 H 2 F 4 ), which comes in different isomer forms [4], was of particular interest, mainly because two isomers, the HFO-1234ze and HFO-123yf, are currently used as refrigerants in the industry, making them rather available for purchase. The choice fell on HFO-1234ze due to the moderate flammability of the yf isomer.…”

A Computational Perspective on the Chemical Reaction of HFO-1234zc with the OH Radical in the Gas Phase and in the Presence of Mineral Dust

“…In recent times, a new generation of fluorinated compounds, like hydrofluoroethers (HFEs) and hydrofluoroolefins (HFOs), is an acceptable alternative to CFCs. HFOs and HFEs are chlorine- and bromine-free compounds, , and because of their shorter lifetimes, they do not contribute significantly to ozone depletion. , Among fluorinated compounds, HFOs are promising alternatives, in particular for replacing conventional refrigerants, and are more highly reactive than HFCs due to the presence of carbon–carbon double bonds. , Hence, HFOs are easily oxidized in the atmosphere, thereby limiting their accumulation in the atmosphere. − …”

“…Among the various HFOs, 1,1,3,3-tetrafluoroprop-1-ene (HFO-1234zc) is proposed for various commercial applications, especially in refrigerators, as industrial coolants, in air conditioners, and as fire suppression and cleaning agents. ,,− Due to the presence of hydrogen atoms and −CC– bonds, it can be easily oxidized in the atmosphere by reacting with the OH radical. , A number of experimental and theoretical studies on the reaction of HFOs with the OH radical are reported in the literature. ,− Using the flash photolysis/resonance fluorescence technique, Orkin et al experimentally studied the reaction of CHFCH–CF 3 with the OH radical and reported a rate constant of 0.71 × 10 –12 cm 3 molecule –1 s –1 at 298 K. Ramanjaneyulu and Rajakumar theoretically studied the H-atom abstraction and OH-addition reaction of CF 2 CHCHF 2 by the OH radical and reported a total rate constant of 0.54 × 10 –12 cm 3 molecule –1 s –1 at 298 K. Papadimitriou et al studied the temperature-dependent oxidation reaction of CF 3 CFCH 2 with the OH radical over the temperature range 206–380 K and reported a rate constant of 1.12 × 10 –12 cm 3 molecule –1 s –1 at 296 K. The above results show the shorter lifetimes of HFOs than those of CFCs or HFCs . However, previous studies , have reported that fluorinated compounds emitted into the atmosphere effectively absorb the earth’s IR radiation and thus act as potent greenhouse gases and these gases contribute significantly to global warming.…”

Versatile Reaction Pathways of 1,1,3,3,3‐Pentafluoropropene at Rh(I) Complexes [Rh(E)(PEt3)3] (E=H, GePh3, Si(OEt)3, F, Cl): C‐F versus C‐H Bond Activation Steps

“…In order to safely use these compounds in industry, extended studies into their properties and reactivity is advisable [3] . Furthermore, they might be considered as useful building blocks to generate molecules of higher value [4] .…”

“…In order to safely use these compounds in industry, extended studies into their properties and reactivity is advisable. [3] Furthermore, they might be considered as useful building blocks to generate molecules of higher value. [4] One approach imparts the development of routes for main group or metal‐mediated functionalization including both C−F and C−H bond activation reactions.…”