Detection and Characterization of the Cumulene Carbenes
H2C5 and H2C6
M. C. McCarthy,
*
M. J. Travers,
A. Kovács,
Wei Chen,
Stewart E. Novick,
C. A. Gottlieb,
P. Thaddeus
Two cumulene carbenes, H2C5 and
H2C6, were detected in a supersonic molecular
beam by Fourier transform microwave spectroscopy. Their rotational and
leading centrifugal distortion constants were determined with high
accuracy, such that the entire radio spectrum can now be calculated.
Like the known carbenes H2C3 and H2C4, both molecules have singlet electronic
ground states and linear carbon-chain backbones. They can be produced
in sufficiently high concentrations in the laboratory that their
electronic spectra, expected to lie in the visible, should be readily
detectable by laser spectroscopy. The microwave spectra of other, more
exotic isomers may be detectable as well.
M. C. McCarthy, M. J. Travers, P. Thaddeus, Division of
Engineering and Applied Sciences, Harvard University, 29 Oxford Street,
Cambridge, MA 02138, USA, and Harvard-Smithsonian Center for
Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA.
A. Kovács and C. A. Gottlieb, Division of Engineering and Applied
Sciences, Harvard University, 29 Oxford Street, Cambridge, MA 02138, USA.
W. Chen and S. E. Novick, Department of Chemistry, Wesleyan University,
Middletown, CT 06459, USA.
*
To whom correspondence should be addressed.
