Abstract
Quadrupoleinteraction frequencies due to Br79 and I127 are reported in a number of crystalline solids. Br79interaction frequencies in bromobenzene derivatives and I127 frequencies in iodobenzene derivatives are correlated with Hammett's σ. The splitting between interaction frequencies found in s‐tribromophenol and related di‐ and tribromobenzene derivatives is explained tentatively on the basis of hindered rotation. Coupling constants and asymmetry parameters for I127 in iodobenzene derivatives are reported and discussed in terms of the single bond, double bond, and ionic character of the carbon‐iodine bond. Owing to the large asymmetry (∼45%) of the I127quadrupole coupling in HIO3, |Δm| = 2 transition could be observed as well as the two |Δm| = 1 transitions. Eight interaction frequencies were found in InI3, two of which (at 26.93 Mc/sec and 36.33 Mc/sec) are attributed to (±7/2 ↔±5/2) and (±9/2 ↔±7/2) transitions of In115. From these two frequencies a coupling constant and asymmetry parameter of 219.8±0.3 Mc/sec and 32.0±4.0%, respectively, are evaluated for In115 in this compound.