17825-75-1Relevant academic research and scientific papers
Singlet Halophenylcarbenes as Strong Hydrogen-Bond Acceptors
Richter, Geneviève,Mendez-Vega, Enrique,Sander, Wolfram
, p. 3524 - 3532 (2016)
Chlorophenylcarbene and fluorophenylcarbene were generated in water-doped argon matrices at cryogenic temperatures by photolysis of the corresponding matrix-isolated diazirines. When diffusion of H2O in solid argon was induced by annealing of the matrices at temperatures above 20 K, hydrogen-bonded complexes between the carbenes and water were formed. UV photolysis of these complexes resulted in the formation of benzaldehyde and hydrogen halides HX. The same products were obtained after photolysis of the diazirines in amorphous water ice. Obviously, the primary insertion product of the carbenes into H-OH is unstable under these conditions, and benzaldehyde is formed via secondary photolysis. The stable primary photochemical insertion product of chlorophenylcarbene into an O-H bond was observed in the reaction of the carbene with methanol.
A search for carbene-solvent interactions using time-resolved infrared spectroscopy
Sun, Ying,Tippmann, Eric M.,Platz, Matthew S.
, p. 1305 - 1307 (2007/10/03)
(Matrix presented) The time-resolved infrared (TRIR) spectra of chlorophenylcarbene (CPC) and fluorophenylcarbene (FPC) were recorded in heptane at ambient temperature. The C-C and C-F vibrational frequencies involving the carbene carbon were obtained in heptane, benzene, and acetonitrile and in heptane containing 0. 1M tetrahydrofuran or benzene. It is concluded that carbene-solvent interactions of CPC and FPC are quite weak.
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.
1,2,4,6-CYCLOHEPTATETRAENE: THE KEY INTERMEDIATE IN ARYLCARBENE INTERCONVERSIONS AND RELATED C7H6 REARRANGEMENTS
McMahon, Robert J.,Abelt, Christopher J.,Chapman, Orville L.,Johnson, Jeffery W.,Kreil, Curits L.,et al.
, p. 2456 - 2469 (2007/10/02)
Thermolysis or photolysis of phenyldiazomethane (2) produces phenylmethylene (3), which ring-expands to give 1,2,4,6-cycloheptatetraene (6).Spectroscopic and chemical evidence rule out bicyclo(4.1.0)hepta-2,4,6-triene (4), cycloheptatrienylidene (5), and bicyclo(3.2.0)hepta-1,3,6-triene (11) intermediates.The strained allene in cycloheptatetraene (6) exhibits infrared absorption at 1824 and 1816 cm-1.Deuterium substitution produces the expected 10-cm-1 shift in the allene absorption.Fluorine or chlorine substitution substantially enhances the allene absorption intensity.Deuterium labeling studies reveal that the intramolecular chemistry of cycloheptatetraene (6) involves reversible thermal or photochemical equilibriation with phenylmethylene (3).The intermolecular chemistry of 6 involves dimerization.At temperatures as low as 10 K, 6 forms a labile (2+2) dimer,7, which undergoes thermally allowed, electrocyclic ring opening to give heptafulvalene (8) upon warming to room temperature.The rearrangements of 7-acetoxynorbornadiene (9), 2-diazobicyclo(3.2.0)hepta-3,6-diene (31), and 8-diazobicyclo(2.2.2)octa-2,5-dien-7-one (33) all involve cycloheptatetraene (6) intermediates.
CHLOROACRYLONITRILE, A DETECTOR SUBSTRATE FOR CARBENE NUCLEOPHILICITY; APPLICATIONS TO PHENYLHALOCABENES
Moss, Robert A.,Fan, Hong,Hadel, Linda M.,Shen, Shilan,Wlostowska, Joanna,et al.
, p. 4779 - 4782 (2007/10/02)
α-Chloroacrylonitrile is an excellent substrate for nucleophilic and ambiphilic carbenes; its use permits visualization of the latent ambiphilic properties of the phenylhalocarbenes.
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 (2007/10/02)
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.
ARE PHENYLHALOCARBENES AMBIPHILIC?
Moss, Robert A.,Lawrynowicz, Witold,Hadel, Linda M.,Hacker, Nigel P.,Turro, Nicholas J.,et al.
, p. 4125 - 4128 (2007/10/02)
In additions to simple alkenes and styrenes at 25 deg C, the selectivities of PhCF and PhCCl are best described as electrophilic.
ABSOLUTE RATE CONSTANTS FOR THE ADDITIONS OF HALOPHENYLCARBENES TO ALKENES; A REACTIVITY-SELECTIVITY RELATION
Cox, D. Phillip,Gould, Ian R.,Hacker, Nigel P.,Moss, Robert A.,Turro, Nicholas J.
, p. 5313 - 5316 (2007/10/02)
The absolute rate constants determined for the additions of FCPh, ClCPh, and BrCPh to Me2C=CMe2, Me2C=CHMe, trans-MeCH=CHEt, and n-BuCH=CH2, appear to follow a reactivity/selectivity pattern of the "normal" (inverse) type.
