Synthesis and Crystal Structure of Nitratocuprates(II) of Alkaline Metals and Ammonium: M3[Cu(NO3)4](NO3) (M= K, NH4, Rb) and Cs2[Cu(NO3)4]

I.V. Morozov, A.A. Fedorova and S.I. Troyanov

Z.anorg.allg.Chem. 624 (1998) p.1543-1547

ABSTRACT. Blue crystals of nitratocuprates(II), M3[Cu(NO3)4](NO3) (M= K (I), NH4 (II), Rb (III)) and Cs2[Cu(NO3)4] (IV) were synthesized from Cu(NO3)2З3H2O and MNO3 by heating at 100-140oC during 3-12 h. X-ray single crystal structures for isotypic I and II reveal the presence of [Cu(NO3)4]2-, NO3- and cations M+. Structure IV contains [Cu(NO3)4]2- and Cs+. In the structures I, II and IV Cu atoms have a square coordination [CuO4] with short Cu-O distances of 1.92-2.00 A, the oxygen atoms belonging to four different NO3 groups. Each coordinated NO3 group is unsymmetrical bidentate with the second, longer Cu-O distance from 2.38 to 2.74 A. Rubidium derivative III was shown to be isotypic to I on the basis of unit cell dimensions and symmetry. Eight coordinate metal(II) environment in tetranitrates is compared for transition metals with different electronic configurations.

Laboratory of Inorganic Synthesis