289-14-5Relevant articles and documents
The Ozonolysis of Ethylene. Microwave Spectrum, Molecular Structure, and Dipole Moment of Ethylene Primary Ozonide (1,2,3-Trioxolane)
Gillies, J. Z.,Gillies, C. W.,Suenram, R. D.,Lovas, F. J.
, p. 7991 - 7999 (1988)
The gas-phase structure of ethylene primary ozonide (CH2CH2OOO) has been determined from millimeter wave spectra of five isotopic species.Partial substitution, rs, parameters for the lowest energy oxygen envelope conformation (Cs symmetry) are r(CC) = 1.546(3) angstroem, r(CO) = 1.417(10) angstroem, r(OO) = 1.453(10) angstroem, r(CHendo) = 1.088(5) angstroem, r(CHexo) = 1.095(5) angstroem, θ(CCO) = 103.9(2) deg, θ(COO) = 102.1(4) deg, θ(OOO) = 100.1(12) deg, and θ(HCH) = 111.6(3) deg.The electric dipole moment of the normal isotopic species is 3.43(4) D.Two vibrational states, 98(6) and 171(18) cm-1 above the ground state, have been assigned to successive excitations of the pseudorotational mode which corresponds to a ring-twisting vibration of the five-membered ring.The barrier to pseudorotation is estimated to be high (greater than 300 to 400 cm-1) in agreement with ab inito MO calculations.Ethylene primary ozonide, dioxirane (CH2OO), formaldehyde, and ethylene secondary ozonide (CH2OCH2OO) are observed as products of the ozone-ethylene reaction in the low-temperature microwave cell. A mechanism of the ozonolysis of ethylene is presented which suggests that the reaction occurs primarily in the condensed phase on the surface of the cell.Microwave techniques utilizing cis- and trans-CHD=CHD show that ozone adds stereospecifically to ethylene in the formation of ethylene primary ozonide.
Matrix effects in the low-temperature ozonation of ethylene, tetramethylethylene and 1-hexene
Samuni,Haas,Fajgar,Pola
, p. 177 - 201 (1998)
The ozonation of the title compounds was studied in argon and CO2 matrices at low temperatures (12-80 K). All three were found to react with ozone in a CO2 matrix deposited at low temperature, and having an amorphous structure. The reaction was found to start at 26 K, the temperature at which the matrix undergoes a phase transition. In contrast, only tetramethylethylene (TME) was found to react in an argon matrix, the other two compounds remaining inactive towards ozone up to the softening temperature of argon (~40 K). These results are interpreted as indicating that reaction between olefins and ozone is initiated at low temperatures once the two reactants are free to move to the required configuration. This idea is supported by molecular dynamics simulations on the TME reaction. The infrared spectra of the primary ozonide of TME, as well as of the primary and secondary ozonide of 1-hexene are reported, and compared with quantum chemical calculations.
Formation of secondary ozonides in the gas phase low-temperature ozonation of primary and secondary alkenes
Fajgar, Radek,Vitek, Josef,Haas, Yehuda,Pola, Josef
, p. 239 - 248 (2007/10/03)
The gas-phase ozonation of a series of alkenes RCH=CH2 (R = Et, Hex), trans-RHC=CHR (R = Me, Et, Pri) and Me2C=CMe2 at -40 to 20°C, and that of ethene H2C=CH2 at -120 to 0°C at 10-4 v/v concentrations in N2 at atmospheric pressure have been studied. Using complementary product analysis by means of GC-FTIR and GC-MS techniques, we present conclusive evidence for the formation of secondary alkene ozonides as high-yield products in all instances except Me2C=CMe2. It is shown that the stereoselectivity for the conversion of trans-RHC=CHR (R = Me, Et, Pri) to trans-secondary ozonides in the gas phase is similar to that observed earlier in solution, and that the yields of secondary ozonides from RHC=CH2, but not those from RHC=CHR, significantly decrease with increasing temperature.