Dissociation rates have been measured by multiphoton ionization and time-resolved photodissociation for benzene-d(6)(.+), naphthalene-h(8)(.+), naphthalene-d(8)(.+), and azulene-h(8)(.+) employing a quadrupole ion trap/reflectron mass spectrometer. Results compare favorably with available data from ICR cells and cylindrical ion traps. Azulene(.+) is photodissociated upon absorption of two 400 nm photons giving C2H2, H-., and H-2 eliminations. Dissociation rate constants measured for naphthalene(.+) and azulene(.+) at identical absolute energies are equal within experimental error. This experimental result is in agreement with previous density functional theory (DFT) calculations that demonstrated the isomerization of azulene(.+) to naphthalene(.+) below the dissociation limit of benzocyclobutadiene(.+) + acetylene.
Determination of the heat of formation of ortho-benzyne by ion cyclotron resonance spectroscopy.
作者:Steven K. Pollack、Warren J. Hehre
DOI:10.1016/0040-4039(80)80106-7
日期:1980.1
IonCyclotronResonanceSpectroscopy has been employed to obtain a value for the heat of formation of ortho-benzyne of 118 ± 5 kcal mol−1.