LAYERED HYDROGENSELENITE .1. SYNTHESIS, STRUCTURE REDETERMINATION OF [CU(HSEO3)(2)(H2O)(2)] AND DETERMINATION OF [CU(HSEO3)(2)(NO3)(2)](2-)CENTER-DOT-2NH(4)(+),NH4NO3 - STRUCTURAL RELATIONSHIPS OF THESE COMPLEXES WITH [CU(HSEO3)(2)]

摘要

The synthesis conditions of two copper hydrogenselenites are described. In the system CuO-SeO2-HNO3-H2O without NH4NO3 or with NH4NO3, the following phases dependent upon the decreasing pH values are observed: in the absence of NH4NO3, [CuSeO3(H2O)(2)] followed by [Cu(HSeO3)(2)] and [CU(HSeO3)(2)(H2O)(2)]; in the presence of NH4NO3, [CuSeO3(H2O)(2)] followed by [Cu(HSeO3)(2)(NO3)(2)](2-). 2NH(4)(+)NH(4)NO(3). The complex [Cu(HSeO3)(2)(H2O)(2)] was previously inadvertenly described as [Cu(HSeO3)(2)(H2O)]. Its structure has been redetermined along with the structure of the new complex [Cu(HSeO3)(2)(NO3)(2)](2-). 2NH(4)(+),NH4NO3. In both structures the copper atoms and the bridging HSeO3- build similar sheets which are interconnected by hydrogen bonds. The structure of [Cu(HSeO3)(2)] may also be regarded as a layered structure similar to the other two. A tentative structural relationship of these three phases is given in solution as well as in the thermal stability field. [Cu(HSeO3)(2)] might be regarded as a layered 'host compound'. [References: 19]