Yuri Suchorski

Evaluation and X-Ray Induced Modification of the Cerium Oxidation State in Cerium Calixarene Complexes

The cerium oxidation state in novel calixarene-supported cerium(IV) β-diketonate complexes [p-tBu-calix[4](OMe)2(O)2]Ce(acac)2 (1) and [p-tBu-calix[4](OMe)2(O)2]Ce(hfac)2 (2), which are a new class of potential precursors for homogeneous oxidative transformations, has been determined using X-ray photoelectron spectroscopy (XPS). Cerium oxidation states between 3.6 and 3.65 were detected, distinctly different from their nominal value of +4. An X-ray induced photoreduction of these compounds was detected. Because of the observed stability of the X-ray modified oxidation state under ambient conditions this effect might be used for a long-standing fine tuning of the Ce oxidation state in cerium calixarenes.

Revisiting Local Electric Fields on Close-Packed Metal Surfaces: Theory versus Experiments

An external electrostatic field of the order of a few tens of a volt per nanometer causes significant changes in the electron density distribution near a metal surface. Because of differing electronic distributions and varying responses of electrons to the applied field for various metals, the resulting local field distribution in the close vicinity of the surface should depend on the electronic properties of the particular metal, even for flat surfaces. Field-free and field-modified electron density distributions for different metal surfaces were calculated using the functional integration method. This approach enables the exchange-correlation effects to be correctly considered and makes it possible to account for the proper field-effect for broad field ranges without using the perturbation theory. The results of calculations are compared with the field-ion microscopic observations.