14541-26-5Relevant articles and documents
Volumes of Activation for the Cycloaddition Reactions of Phenylhalocarbenes to Alkenes
Turro, Nicholas J.,Okamoto, Masami,Gould, Ian R.,Moss, Robert A.,Lawrynowicz, Witold,Hadel, Linda M.
, p. 4973 - 4976 (1987)
The absolute rate constants for the cycloaddition reactions of three arylhalocarbenes to two alkenes have been measured as a function of pressure in the range 0.1 to 203 MPa.In all cases the observed rate constants were found to increase with increasing pressure.The magnitude of the derived activation volumes falls in the range of -10 to -18 cm3/mol and does not depend on solvent.The results rule out a late, two-bond transition state and a bipolar single-bond transition state but are consistent with the reversible formation of a carbene-alkene complex or an early one- or two-bond transition state.
First direct observation of reactive carbenes in the cavities of cation-exchanged Y zeolites
Moya-Barrios, Reinaldo,Cozens, Frances L.
, p. 881 - 884 (2007/10/03)
(Equation presented) Herein we report the first direct observation of reactive carbenes within the cavities of cation-exchanged Y zeolites. Chloro(phenyl)- and bromo(phenyl)carbenes were generated upon laser photolysis of 3-halo-3-phenyldiazirines incorporated within dry zeolites and the absolute reactivity of the carbenes was investigated as a function of counterbalancing cation and coincorporated quenchers in order to elucidate the behavior of these intermediates within zeolites. Product analysis performed upon thermolysis of the diazirine in Y zeolites yielded products that were identified as those derived from the carbene.
The Experimental Heats of Formation and Reaction of Singlet Carbenes via Time-Resolved Photoacoustic Calorimetry
LaVilla, Joseph A.,Goodman, Joshua L.
, p. 712 - 714 (2007/10/02)
The heats of formation and reaction of several singlet carbenes are determined by time-resolved photoacoustic calorimetry.The most selective and least reactive carbene examined, methoxychlorocarbene, is the most stable and reacts least exothermically with CH3OH.The phenylhalocarbenes have similar stabilities and reaction exothermicities with CH3OH.The experimental carbene heats of formation in solution are systematically lower and the stabilization energies higher than the values from MNDO calculations.This potentially result from (i) solvation of the carbene, (ii) an unresolved reaction volume change, or (iii) incorrect MNDO calculated carbene and diaziridine enthalpies.