On the nature of the trigonal fields in hexaaquachromium(III) in guanidinium aluminum sulfate hexahydrate

Zeeman and site selective luminescence and excitation spectra in the region of the E-2 <-- (4)A(2) transition are reported for the hexaaquachromium(II I) complex in the trigonal ferroelectric guanidinium aluminum sulfate hexah ydrate, The two prominent transitions are due to the R-1 lines of the two s ites of C-3 and C-3v point symmetry. The two R-1 lines display g(parallel t o) = -3.1 and g(parallel to) = -3.2, respectively, and show no measurable Z eeman shift or splitting with B perpendicular to c, This behavior is consis tent with the presence of a very large trigonal field. A peculiar feature o f the present system is the conspicuous absence of any prominent R-2 line. From the Zeeman data with B perpendicular to c and a comparison of vibratio nal sidelines in excitation and luminescence it is concluded that the R-2 l evel strongly interacts with vibrational levels.