A lanthanide oxyhalide is an inorganic compound that contains a lanthanide (Ln), oxide, and halide (X). The simplest members have the formula LnOX. The three heavier member of this class, lanthanide oxychlorides, lanthanide oxybromides, and lanthanide oxyiodides, can be prepared by hydrolysis of the corresponding lanthanide trihalides : LnX3 + H2O → LnOX + 2 HX (X = Cl, Br, I)
The lanthanide oxyfluorides are the unique member of the series. They are prepared by the thermal reaction of the trifluorides and the oxides:
Inventory + Lanthanide oxyhalideLnOFstructure type LnOCl structure typeLnOBrstructure typeLnOIstructure type LaOF fluorite LaOCl PbFCl LaOBr PbFCl LaOI CeOF fluorite CeOCl PbFCl CeOBr PbFCl CeOI PrOF fluorite PrOCl PbFCl PrOBr PbFCl PrOI ?? NdOF fluorite NdOCl PbFClNdOBr PbFCl NdOI PmOF fluorite PmOCl ??I PmOBr PmOI SmOF fluorite SmOCl PbFCl SmOBr PbFCl SmOI EuOF fluorite EuOCl PbFCl EuOBr PbFCl EuOI GdOF fluorite GdOCl PbFCl GdOBr PbFCl GdOI TbOF TbOCl PbFCl TbOBr PbFCl TbOI DyOF fluorite DyOCl PbFClDyOBr PbFCl DyOI HoOF fluorite HoOCl PbFCl HoOBr PbFCl HoOI ErOF fluorite ErOCl dimorphic: PbFCl & SmIS ErOBr PbFCl ErOI TmOF fluorite TmOCl SmIS TmOBr PbFCl LuOI YbOF fluorite YbOCl SmIS YOBr PbFCl YOI LuOF fluorite LuOCl SmIS-type LuOBr PbFCl LuOI PbFCl
Structures
The lanthanide oxychlorides, oxybromides, and oxyiodides adopt layered structures featuring 8-or 9-coordinated Ln ions sandwiched between arrays of halide and oxides. Most of the lighter oxychlorides follow the PbFCl motif, but the three heaviest adopt structures like that of SmSI (samarium sulfide iodide).
The oxyfluorides adopt the fluorite structure.
References