155Gd Mossbauer Isomer Shifts and Quadrupole Coupling Constants of Gadolinium Complexes

摘要

We have examined the 155Gd Mossbauer spectra at 12 K for 25 complexes having different coordination numbers and different ratios of coordinating oxygen to nitrogen atoms. The isomer shift decreases in the order: GdO10 ≈ GdO9 > GdN2O7 ≥ GdO8 ≈ GdN6O2 ≥ GdO7 ≥ GdO6 > GdNg ≥ GdNg. The s electron density at the nucleus is larger as the coordination number decreases and as the coordinating atoms change from oxygen to nitrogen, suggesting the covalency in the bonding.