Optical Identification of the Resonance-Stabilized -Ethynylbenzyl Radical.

We report the spectroscopic observation of the jet-cooled -ethynylbenzyl (PEB) radical, a resonance-stabilized isomer of CH. The radical was produced in a discharge of -ethynyltoluene diluted in argon and probed by resonant two-color two-photon ionization (R2C2PI) spectroscopy. The origin of the ()-() transition of PEB appears at 19,506 cm.

Electronic Spectroscopy of - and --Vinylbenzyl Radicals.

The (″)-(″) electronic transition of resonance-stabilized radical CH isomers - and -vinylbenzyl (MVB) has been investigated using resonant two-color two-photon ionization (R2C2PI) and laser-induced fluorescence. The radicals were produced in a discharge of -vinyltoluene diluted in Ar and probed under jet-cooled conditions. The origin bands of the and conformers are at 19 037 and 18 939 cm, respectively.

Gas-Phase Optical Detection of 3-Ethynylcyclopentenyl: A Resonance-Stabilized CH Radical with an Embedded 1-Vinylpropargyl Chromophore.

The 3-ethynylcyclopentenyl radical (3ecpr) has been identified as the carrier of an electronic spectrum with origin at 21792 cm using resonant ionization and laser-induced fluorescence spectroscopies. The radical was first detected in a toluene discharge and is most efficiently produced from 1,6-heptadiyne. Overwhelming spectroscopic and chemical evidence support our diagnosis: (1) the observed (6.