Preparation and Characterization of (C6H5CH2CH2NH3)4BiI7 · H2O, (C6H5CH2CH2NH3)3BiBr6 and (C6H5CH2CH2NH3)3BiCl6

The title compounds were prepared and characterized analytically, structurally, and spectroscopically. They contain isolated BiX 6 (X = I. Br, Cl) anions. Their optical absorption spectra show excitonic bands in the UV-visible spectral region. These bands occur at higher energies than the corresponding bands of R 3 M 2 X 9 (R = Me m NH 4-m ; m = 1,2, 3, 4).