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A relation between the quadrupole coupling constant e2Qqzz and asymmetry parameter η has been found for a series of meta-substituted iodobenzene derivatives. The relationships e2Qqzz(η) for electrondonor and electron-acceptor substituents have the same form but different numerical values of parameters. The average time of full electron transfer via tunneling has been evaluated.

This is a review of investigations on iodo-benzoic acid, iodohippuric acid, and iodophenol derivatives by NQR, NMR, and emission Mössbauer spectroscopy. The influence of intermolecular, intramolecular, and bifurcated O-H…I and O-H…O bonds on the properties of iodine-carbon bonds is demonstrated. Ionized and non-ionized forms of tyrosine differ by the probability of H-bond formation. The simultaneous use of 127I NQR and emission Mössbauer 125I spectroscopy open the possibility to determine the types of tellurium-organic substances formed in the process of K-decay of 125I.

The full127I NQR spectra of a series of iodo-substituted phenols and phenylmercury phenoxides have been studied. The quadrupole coupling constants and asymmetry parameters have been determined. The character of the OH...Hal hydrogen bond has been found to depend on the nature of substituents in the ring. Correlation dependences of the asymmetry parameters on the sum of the substituents resonance constants have been found for both coordinated as well as for non-coordinated iodine atoms.

We have studied the complete127I spectra and obtained the values of the quadrupole coupling constants e2Qqzz and the asymmetry parameters η in a series of substituted α-iodothiophenes. Using an additive scheme, we have calculated e2Qqzz and determined the substituent increments.

Br79 NQR frequencies of a number of bromothiophene derivatives have been measured at 77°K. The frequencies correlate with Hammett δ values and this correlation demonstrates the importance of the inductive effect. The influences of more than one substituent on the thiophene ring are additive.

The127I NQR spectra of the tetraiodo-, triiodonitro-, and diiodonitrotrifluoromethylthioethylenes were studied. The frequencies of the iodine atoms increase when electron-acceptor substituents are inserted into the molecule of iodoethylenes.

Iodonitromethane forms nσ complexes with organic ligands with low127I asymmetry parameters and positive charge on the iodine atom.

The complete79Br and127I NQR spectra of a number of bromo and iodo derivatives of acetylene were studied for the first time, and the field constants of the NQR frequencies were determined. It was found that the asymmetry parameters in them are low. Changes in the field constants are determined by the competing conjugation of the iodine atom and the corresponding substituents.