Rhodium and Iridium Dicarbonyl Acetylacetonates

Besides Ni(II), Pd(II), and Pt(II), the isoelectronic Co(I), Rh(I), and Ir(I) / complexes exhibit square planar geometry. Molecules of the type 20 dicar-bonylacetylacetonates (R = H), M = Rh (57, 270) and Ir (56) have been shown to stack with relatively short metal-metal bond distance (20, 32 ), Table XVI. The single-crystal conductivities of 20 (M = Rh, Ir) have been investigated with the results. Table XVI, suggesting that these materials are in- 

Measurements have been made on the influence of mechanical strain (25, 217) on the electrical properties of M(CO)2(acac) (M = Rh, Ir). It was found (25) that 20 (R = H M = Ir) shows a sizable piezoelectric effect, while an extremely small effect was noted for 20 (R=H, M = Rh). The pressure dependence of the conductivity of 20 (M=Ir, R=H) reveals an increase of the 

The polarized single crystal specular reflectance and solution absorption spectra have been reported for 20 (M = Rh, Ir R = H) (44, 474). A high reflectivity at 19100 cm (e — 14000 1/mole cm) and 17600 cm (s 15000 1/mole cm) were reported for the rhodium and iridium complexes respectively. These reflectances account for the metallic luster of these complexes and are assigned to a - L r transition. The final state is characterized as a Frenkel exciton consistent with the poorly conducting character of these complexes. 

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