Mössbauer‐Effect Studies in ¹²⁹ICN Molecular Crystals Available to Purchase

The Mössbauer effect in ¹²⁹I $(Er = 27.8 keV)$ has been used to investigate some properties of ICN crystals at 100°K. From the quadrupole split spectrum the value of $e2qQ(127I)$ was found to be −2640 ± 20 Mc/sec and the isomer shift +0.119 ± 0.002 cm/sec with respect to a ZnTe source. The $η$ parameter was found to be zero. From these values, it was concluded that the iodine promotes 0.27 $p$ electrons (there is no $sp$ hybridization) to the cyanide group. From considerations based on NQR data in BrCN and ICN and from the fact that no anisotropy was detected in the recoilless fraction, it was concluded that intermolecular (covalent) bonding to form a chain structure is negligible. The absolute recoilless fraction at 100°K was found to be 0.012 ± 002 corresponding to a Debye temperature of 61 ± 5°K.