COMPARATIVE-STUDIES ON PERIODATOCUPRATE(II, III) AND TELLURATOCUPRATE(II, III)

The crystal structures, electronic spectra, and Cu2p XPS of Cu(III) co mplexes Na4H[Cu(H2TeO6)(2)]. 17H(2)O and Na4K[Cu(HlO(6))(2)]. 12H(2)O have been described. The characterizations of a Cu(III) atom in a comp lex are as follows: (i) In a square-planar coordination, the average b ond length of Cu-O is 0.183 nm, shorter than the 0.190-0.200 nm found for a Cu(II) complex. (2) The ''blue shift'' occurs for d-d transition s in the electronic spectrum of the Cu(III) complex compared to those of its related Cu(II) complex, resulting from the higher valence state . (3) Cu(III) compounds with CuO4 square-planar coordination are expec ted to be diamagnetic whereas Cu(II) compounds to be paramagnetic. (4) Comprehensive investigations on Cu2p XPS show that the binding energy of Cu2p(3/2) of a pure Cu(III) compound is about 2.0 eV higher than t hat of its corresponding Cu(II) compound: the shake-up satellites do n ot appear in the Cu2p XPS for a pure diamagnetic Cu(III) compound, the same as found for a diamagnetic Ni(II) compound: the FWHM of the sign al of Cu2p XPS may become broader for Cu(III) compound because its cor e hole's lifetime shortens due to the higher valence state of copper. (C) 1995 Academic Press, Inc.