Ab initio calculations on cofacial dimers of palladium bis(glyoximates) are reported and are used to rationalize the temperature-dependent conductivity of the low-dimensional, partially-oxidized material Pd(dpg)20.20+(I5−)0.20 (dpg = diphenylglyoximato). The band structure near the Fermi level is dominated by two bands, of b3g and au symmetry in the dimer, that arise from the ligand π orbitais. Near the observed (dpg)2Pd-Pd(dpg)2 staggering angle (90°), the b3g bandwidth is zero, and the au band exhibits sharp variations with librational (twist) motion about the intermolecular Pd-Pd vector. This in turn, combined with the narrow bandwidth (calculated to be ~0.60 eV in a tight-binding model) implies that the electronic states are localized and that the material should be a hopping semiconductor rather than a molecular metal, in agreement with experiment.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry