On the flexibility of the structural framework of cubic LAMOX compounds, in relationship with their anionic conduction properties.

A mathematical analysis of the cubic crystal structure of fast oxide-ion conductor beta-La(2)Mo(2)O(9) (and derived members of the LAMOX family) shows that its cationic sublattice can behave as a semirigid framework. Tilt/rotation of rigid [O1La(3)Mo] anti-tetrahedral units about their 3-fold axis can open up tunnels in the cationic framework, therefore favoring the mobility of O2 and O3 oxide ions located in these tunnels, as confirmed by molecular dynamics simulations. Such a process is likely to assist the anionic transport and explain the postulated transition from Arrhenius-type to VTF (Vogel-Tamman-Fulcher)-type behavior propounded to account for the peculiar conductivity curvature observed at high temperature in all the cubic LAMOX compounds.

Reduction of dipyrido-[3,2-a:2',3'-c]-phenazine (dppz) by photolysis in ethanol solution.

Photolysis of dipyrido-[3,2-a:2',3'-c]-phenazine (dppz) (1) in ethanol solution leads to the formation of 9,14-dihydrodipyridophenazine (2), which has been characterised by detailed NMR analysis, UV/VIS absorption spectroscopy, and theoretical calculations which reveal that its red colour is due to a low-lying intramolecular charge transfer state.