ELECTRON-SPIN RESONANCE OF I-127 ATOMS TRAPPED IN XE MATRICES

The ESR spectrum arising from the trapped 127I atoms has been observed in photolysis of HI in Xe matrices at 4.2 K. This may be the first clear detection of trapped halogen atoms in the solid matrices. The g and hyperfine coupling tensors are axially symmetric and the principal values are as follows: g∥ = 1.400, g⊥ = 2.532, A ∥ = 889 MHz, and A⊥ = 1605 MHz. The quadrupole coupling tensor has been determined to be |Q∥| = 74 MHz assuming axial symmetry. The approximate feature of the observed g and hyperfine tensors can be interpreted in terms of a simple crystal field model. However, a better understanding of the observed values requires a consideration of the effect of matrix wave functions as well as the dynamic Jahan-Teller effect. The radial parameters 〈r-3〉 estimated from the A and Q tensors are approximately consistent with the atomic beam data for free 127I atoms, giving conclusive evidence that the species is trapped 127I atoms. © 1979 American Institute of Physics.