A matrix isolation ESR and theoretical study of MgN

Matrix isolation experiments have been conducted on the Mg¹⁴N, ²⁵Mg¹⁴N, Mg¹⁵N, and ²⁵Mg¹⁵N radicals which were formed by the reaction of a plume of magnesium metal produced with laser ablation and either acetonitrile vapour or nitrogen atoms. The radicals were isolated in an inert neon matrix at 4.3 K and studied with electron spin resonance spectroscopy. The ground electronic state of MgN was determined to be ⁴Σ^-. The following magnetic parameters were determined experimentally for MgN: g_⊥ = 2.004 78 (2), g_∥ = 2.001 72 (4), |D| = 9797 (6) MHz, A_⊥(¹⁴N) = 19.7 (2) MHz, A_∥ (¹⁴N) = -4.0 (3) MHz, A_⊥(¹⁵N) = 27.5 (3) MHz, A_∥ (¹⁵N) = -5.7 (3) MHz, A_⊥ (²⁵Mg) = -60.7 (5) MHz, and A_∥(²⁵Mg) = -65 (3) MHz. The low-lying electronic states of MgN were also investigated using the complete active space multiconfigurational self-consistent field technique. By plotting the potential energy surface, theoretical parameters for the ground state with a configuration of 5σ²6σ²7σ¹2π¹2π¹ were able to be determined, including r_e = 2.090 Å and D_e = 11.28 kcal/mol.