Fleming, H. Creswell published the artcileNuclear quadrupole resonance investigation of iodine monochloride complexed with pyridines, Synthetic Route of 6443-90-9, the publication is Journal of the American Chemical Society (1971), 93(20), 5030-4, database is CAplus.
The 35Cl and 127I nuclear quadrupole resonance absorption frequencies of pyridine-ICl and 4-methylpyridine-ICI was measured as a function of temperature Their resp. values at 273.2°K are 21.136 ± 0.01, 21.175 ± 0.01, 464.28 ± 0.04, and 462.76 ± 0.04 MHz. Their temperature coefficients were +2.2, +2.5, – 28, and – 24 kHz/°K. Application of the Townes and Dailey theory with neglect of s hydridization at the halogen atoms results in the following charge ds. in each complex: pyridine (or 4-methylpyridine) +0.26; I +0.35; and Cl – 0.61 electron. A valence-bond interpretation indicates a 57% contribution of the “nobond” wave function to the ground state. A representation in which the charge-transfer and electrostatic wave functions are explicitly included contains a maximum of 26% charge-transfer character in the ground-state wave function. Classical electrostatic forces thus appear to play a dominant role in the stabilization of these complexes. The charge-transfer contributions are nonnegligible, but a representation of the complex structure based completely on the chargetransfer model is likely to give misleading results.
Journal of the American Chemical Society published new progress about 6443-90-9. 6443-90-9 belongs to iodides-buliding-blocks, auxiliary class Pyridines, name is Pyridine Iodochloride complex, and the molecular formula is C5H5ClIN, Synthetic Route of 6443-90-9.
Referemce:
https://en.wikipedia.org/wiki/Iodide,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com