Neon matrix ESR investigation of12C+2and13C+2: Confirmation of a4Sgr;minus;gground electronic state

摘要

The12C+2and13C+2cation radicals have been isolated in neon matrices by the photoionization of C2(g) generated by the laser vaporization of thin carbon disks. A new procedure of supporting and thermally outgassing such targets for laser vaporization ESR studies in rare gas matrices is described. The ESR results confirm the4Sgr;minus;gground electronic state assignment for C+2and provide a valence orbital electronic structure characterization based on the13C hyperfine structure (hfs). The ESR lines are extremely narrow for a highhyphen;spin powder sample and an intense offhyphen;angle or lsquo;lsquo;extrarsquo;rsquo; absorption feature exibits unusual hfs. Normally forbidden (Dgr;MS1) transitions were detected at low magnetic fields. The magnetic parameters for13C+2in a neon matrix at 4 K are:D=3668(3) MHz;gperp;=2.0018(5);gpar;=2.0023(5); Verbar;Apar;Verbar; =99.4(8) MHz; and Verbar;Aperp;Verbar; =95.2(5) MHz.