Photoreduction of cerium (IV) in Ce sub 2 (O sup i Pr) sub 8 ( sup i PrOH) sub 2. Characterization and structure of Ce sub 4 O(O sup i Pr) sub 13 ( sup i PrOH)

Visible irradiation of Ce{sub 2}(O{sup i}Pr){sub 8}({sup i}PrOH){sub 2} yields the mixed-valence compound Ce{sub 4}O(O{sup i}Pr){sub 13}({sup i}PrOH), characterized by {sup 1}H NMR and infrared spectra, elemental analysis, and x-ray diffraction. The structure is described as Ce{sub 4}({mu}{sub 4}{minus}O)({mu}{sub 3}{minus}O{sup i}Pr){sub 2}({mu}{sub 2}{minus}O{sup i}Pr){sub 4}-(O{sup i}Pr){sub 7}({sup i}PrOH). The Ce{sub 4}({mu}{minus}O) core has a butterfly form, with a crystallographic C{sub 2} axis that passes through the oxide ion and the center of a symmetric hydrogen bond between the coordinated alcohol and one terminal alkoxide. This photoredox reaction cannot be thermally induced and requires that hydrogen be present on the carbon {alpha} to the alkoxide oxygen. Magnetic susceptibility and EPR studies show the compound to be paramagnetic. Two temperature ranges of Curie-Weiss behavior are observed with {mu}{sub eff} = 2.7 {mu}{sub B} from 80 to 300 K. Crystal data ({minus}130C) are presented for the complex. 25 refs., 2 figs., 4 tabs.