Matrix-Isolation ESR Studies of the Various Isotopomers of the CH 3 Zn and ZnH Radicals: Comparisons with ab Initio Theoretical Calculations

The 12CH3Zn, 12CH367Zn, 13CH3Zn, 13CH367Zn, 13CD367Zn, and 13CD3Zn radicals have been isolated in an inert neon matrix at 4.3 K. Their electronic structure has been probed for the first time using matrix-isolation electron spin resonance spectroscopy (MI-ESR). These radicals were generated by the reaction of laser-ablated zinc metal with the appropriate methyl precursor. The magnetic parameters (MHz) were determined to be g⊥ = 1.9835(4), A⊥(H) = 14(1), A⊥(D) = 2.2(4), A⊥(13C) = 166(3), and A⊥(67Zn) = 547(1). Estimates were derived for A∥(13C) = 211(50) and A∥(67Zn) = 608(5). The 67ZnH radical was also generated by the reaction of laser-ablated zinc metal and hydrogen gas and studied for the first time by MI-ESR after isolation in solid neon matrixes at 4 K. The values of the 67ZnH magnetic parameters (MHz) were determined to be g⊥ = 1.9841(3), g∥ = 1.9990(5), A⊥(H) = 505(1), A∥(H) = 503(1), A⊥(67Zn) = 615(1), and A∥(67Zn) = 660(1). Earlier argon MI-ESR studies produced ZnH by conventional high-temperature...