Field-stepwise-swept solid-state 127I NMR of 1,4-diiodobenzene

Field-stepwise-swept solid-state ¹²⁷I NMR experiments of 1,4-diiodobenzene, C₆H₄I₂, applied to a Zeeman-perturbed NQR region, have been presented. A series of QCPMG measurements is performed at T = 90 K with resonant frequencies of 271 MHz in the range of magnetic fields from 2.5 T to zero with the interval of 12 mT. The spectral simulation, in which a numerical calculation involves the diagonalization of the combined Zeeman-quadrupolar Hamiltonian, provides quadrupole coupling constant (C_Q) = 1863(5) MHz and the asymmetry parameter (η_Q) = 0.04(2). The ¹²⁷I NQR spectrum is observed at T = 90 K, which is consistent in the above experimental results.