Nuclear Quadrupole Resonance of Tellurium Tetraiodide

The nuclear quadrupole resonance (NQ R) of 127I in tellurium tetraiodide was observed, and the Zeeman effect on a single crystal was examined. Tellurium tetraiodide shows ten resonance lines in the frequency range from 195 to 260 MHz. From the analysis of the zero-splitting patterns, it has become apparent that tellurium tetraiodide crystals contain eight nonequivalent iodine atoms, two of which yield large asymmetry parameters (94.9% and 73.8%) and small quadrupole coupling constants (775.07 MHz and 929.55 MHz) at room temperature. These two may be assigned to the bridging iodine atoms, but they differ markedly from each other in the temperature dependences of e2Q q/h and η. The other six iodine atoms have small η values and coupling constants of about 1600 MHz; they are assigned to the terminal atoms. From these results, it may be concluded that each tellurium atom has three terminal and two bridging iodine atoms.