A new family of layered bismuth oxohalides

A series of layered bismuth oxohalides, belonging to three new structural types, have been predicted and synthesized. In all cases, the fluorite-like [Bi2O2] layers are alternatively separated by metal-halide layers of the CsCl type and perovskite-like sheets of varied width. The structural motifs of the new compounds have been confirmed by X-ray crystallography for Bi4NdTi1.6Nb0.4Cs0.6O11Br2 (space group P4/mmm, a 3.8571(1) Angstrom, c 25.280(1) Angstrom, R-wp = 0.092, R-p = 0.063) and Bi4Nd2Ti2.4Fe0.6Cs0.6O14Cl2 (space group P4/mmm, a = 3.8424(1) Angstrom, c = 26.622(1) Angstrom, R-wp = 0.062, R-p = 0.043). These results are compared with the data on the related layered family BIPOX. The possibilities of further development of different families of layered bismuth oxohalides containing fluorite-like metal-oxygen layers are discussed.</p