Laser vaporization generation of Y ??B+, Y ??B+, and YAI+ for electron spin resonance studies in neon matrices at 4 K: comparison with theoretical calculations

The first spectroscopic investigation of 89Y 10B+, 89Y 11B+, and 89Y 27Al+ is reported, revealing that both of these diatomic cation radicals have X 4?- electronic ground states. The ions were generated by three high energy techniques in combination with neon matrix isolation at 4 K and studied by electron spin resonance (ESR) spectroscopy. The generation methods included pulsed laser vaporization of the metal alloys, photoionization at 16.8 eV during matrix deposition, and x-irradiation at 80 keV of the matrix sample following deposition. Hyperfine interactions were resolved for all of the above nuclei and were compared with calculated isotropic and dipolar components of the A tensor. The yttrium 5s character observed in YAlf was significantly larger than that in YB+ based upon the observed nuclear hyperfine interactions. The calculated electronic structure properties showed agreement with this trend in the observed Aiso parameters. In addition, qualitative descriptions of the bonding properties are also presented which are consistent with the magnetic parameters obtained from the ESR measurements. The magnetic parameters for Y ?B+ in neon at 4 K are gl =1.959(1), A, (Y) =33.6(4) MHz, and AL (11B) =65.9(4) MHz. For YAl+, g, =1.942(1),A, =142(l) MHz, andA, (Al)=73(1) MHz.