Polarized electronic absorption spectra for dirhodium(II) tetraacetate dihydrate

Single-crystal polarized absorption spectra are reported for the 1-bar 01 face of Rh/sub 2/(O/sub 2/CCH/sub 3/)/sub 4/2H/sub 2/O in the region of 15,500-30,000 cm/sup -1/ and at temperatures of 300 and 15 K. an absorption band with a maximum at 17,300 cm/sup -1/ possesses vibrational structure in the perpendicular to b polarization. It corresponds to molecular x,y polarization and has been assigned as Rh-Rh ..pi..*..-->..Rh-Rh sigma*. Weaker absorptions with maxima at 23,300 cm/sup -1/ in perpendicular to b and 22,200 cm/sup -1/ in double vertical bars b indicate the presence of more than one transition in this region. Possible assignments for these transitions are discussed. 3 figures.