38664-34-5

Upstream product

• 76-16-4 Hexafluoroethane 
• 18851-76-8 trifluoromethylium 
• 355-25-9 perfluorobutane 

Relevant academic research and scientific papers

Study of the gas phase reactions of several perfluorocarbons with positive ions of atmospheric interest

The bimolecular rate coefficients and ion products for the reactions of H3O+, NO+, O2+, H2O+, N2O+, O+, CO2+, CO+, N+, and N2+ with three fluoroalkenes (C2F4, C3F6, and 2-C4F8) and three fully saturated perfluorocarbons (C2F6, C3F8, and n-C4F10) at 300 K are reported. All six perfluorocarbons are found to be unreactive with NO+. C2F6 is also unreactive with O2+, H2O+, and N2O+, and C3F8 and n-C4F10 are also unreactive with O2+. C3F6 is the only perfluorocarbon studied that reacts with H3O+ at a measurable rate. All the other reactions take place at or close to the collisional rate, the exceptions being the reactions of N2O+ with C2F4 and C3F8, and CO2+ with C2F4 and C2F6, for which the experimental rate coefficients show marked departures from the collisional values. It is proposed that most of the reactions proceed through a complex intermediate resulting in electrophilic attack by the ion on the perfluorocarbon. This mechanism generally takes precedent over "long-range" (formal) charge transfer. This work is of possible relevance to atmospheric ion-chemistry and plasma processes and may also be pertinent to the use of chemical ionization mass spectrometers for the trace detection of perflurocarbons in the environment.

Chemistry of CFn(1+) (n = 1-3) Ions with Halocarbons

The gas-phase reactions of CF(1+), CF2(1+), and CF3(1+) with the halocarbons CF3Cl, CF3Br, CF3I, CF4, and C2F6 have been studied using a variable-temperature-selected ion flow tube (VT-SIFT) instrument at 300 and 496 K.The ion CF(1+) reacts rapidly with CF3X (X = Cl, Br, I) producing the ions CF2X(1+).In the reaction of CF(1+) with CF3Cl, CF3(1+) is also produced as a minor product.Curvature was observed in the pseudo-first-order kinetics plots for the reactions of CF(1+) with CF4 and C2F6.In both cases the curvature is attributed to the presence of two or more CF(1+) states (probably vibrational) of differing reactivities toward the perfluorocarbon of interest.This conclusion is supported by our observation of charge transfer from CF(1+) to NO, a reaction which is endothermic by 15 kJ/mol for the ground state of CF(1+).CF(1+) is unreactive with O2, N2, and Xe.The reactions of CF2(1+) with CF3X yield CF3(1+) and CF2X(1+) for X = Cl and Br; for X = I, CF2I(1+) and CF3I(1+) are produced.The overall reactions proceed at approximately the collision rate at 300 and 496 K, and the branching ratios are not strongly dependent on temperature.The reactions of CF2(1+) with CF4 and C2F6 produce CF3(1+) and C2F5(1+), respectively.The rate constants decrease significantly with increasing temperature.CF2(1+) reacts rapidly by charge transfer with NO.The reaction of CF2(1+) with O2, producing CF2O(1+), is inefficient.CF2(1+) is unreactive with N2.CF3(1+) reacts with CF3X (X = Cl, Br, I) at rates below the collision values, producing a single ionic product, CF2X(1+).While the rate constants for the reactions of CF3(1+) with CF3X increase in the series with increasing CF3X mass, the rate constants for reaction with each CF3X decrease sharply with increasing temperature.A mechanism is proposed in which the reaction proceeds on a double-well potential energy surface.No reaction was observed for the CF3(1+)/CF4 system.CF3(1+) appeared to react very slowly with C2F6 and NO, producing C2F5(1+) and NO(1+), respectively, but reactions with impurities in the neutral reagents cannot be ruled out as the source of these ions.CF3(1+) is unreactive with O2 and N2.

Kinetic Energy Dependence of the Reactions of O(1+) and O2(1+) with CF4 and C2F6

Guided ion beam techniques are used to measure cross sections as a function of kinetic energy for the reaction of O(1+) and O2(1+) with CF4 and C2F6.The predominant ions formed in these fluorocarbon system correspond to dissociative charge-transfer reactions, with small amounts of FCO(1+) and F2CO(1+) being formed.The thresholds and shapes of dissociative charge-transfer cross sections are explained in terms of vertical ionization to various electronic states of CF4(1+) and C2F6(1+).In the O(1+) reactions, fluoride transfer to form CF3(1+) in the CF4 system and C2F5(1+) in the C2F6 system is also observed at thermal energies.The formation of carbon oxyfluoride ions in these systems is postulated to occur by insertion of the oxygen ions into C-F bonds of the fluorocarbon molecules.From the O2(1+) + CF4 and O(1+) + C2F6 systems, ΔfH(F2CO(1+)) is determined.The relationship of these reactions to plasma deposition and etching is discussed.