Abstract 14 N NQR spectra of 1,10-phenanthroline and of dicyano bis(1,10-phenanthroline)iron(lll) were obtained at room temperature. An analysis based on the shifts of the NQR frequencies and in the topology of the charge distribution in a model (pyridine) showed that the complex formation produces a strong decrease in the N valence shell nonbonded maximum and an increase in the bonded density along each of the N - H bond directions. The NQR spectrum showed that the complex formation produces only small changes in the charge distribution of the cyanide groups.