Synthesis and crystal structure of New Amminecopper(II) Nitrates: [Cu(NH₃)₂](NO₃)₂ and [Cu(NH₃)](NO₃)₂

Abstract

[Cu(NH3)2](NO3)2 (I) and [Cu(NH3](NO3)2 (II) were synthesized by interaction of molten NH4NO3 with [Cu(NH3)4](NO3)2 and Cu(NO3)2 · 3 H2O, respectively, at 180 to 195°C for 24 hr. According to X‐Ray single crystal analysis, I is orthorhombic (sp. gr. Pbca) with a = 5.678(1), b = 9.765(2), c = 11.596(2) Å, Z = 4, R = 0.060; II is monoclinic (sp. gr. P21/c) with a = 6.670(1), b = 8.658(2), c = 9.661(2) Å, β = 101.78(2)°, Z = 4, R = 0.027. In both structures, the nearest coordination environment of Cu is a slightly distorted square formed by N (from NH3) and O atoms (from NO3 groups). The structure of I consists of centrosymmetrical [Cu(NH3)2](NO3)2 molecules linked by hydrogen bonds. The CuN and CuO distances are 1.98 and 2.01 Å, respectively. In II, the CuN distance is 1.95 Å, the CuO distances are 1.96, 2.02, and 2.03 Å. The [CuO3NH3] squares are connected by NO3 bridges into zigzag chains, which are linked into layers by longer CuO interactions (2.31 Å). Obviously, the layers are additionally strengthened and held together by hydrogen bonds.

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

“…The reaction lasted for a longer time due to slower water evaporation. For example, pure Rb 3 [Cu(NO 3 ) 4 ](NO 3 ) has been obtained by this method during 2 days using the reactor described in [7]. However, the absence of a molten phase during most of the reaction period resulted in the formation of fine crystalline powder samples.…”

“…The synthetic method commonly used for the preparation of nitratometallates traditionally excludes the presence of water as is actually necessary for the synthesis of water-free nitrates, M(NO 3 ) 2 . However, it has been shown in our work on the synthesis of amminecopper(II) nitrates that water can be quantitatively removed during interaction of Cu(NO 3 ) 2´3 H 2 O with excess NH 4 NO 3 [7]. Moreover, a supposition was made concerning intermediate formation of a water free nitratocuprate, nCu(NO 3 ) 2´m NH 4 NO 3 .…”

Ni(NH3)2(NO3)2—A 3-D Network through Bridging Nitrate Units Isolated from the Thermal Decomposition of Nickel Hexammine Dinitrate

“…This structure type presents the first evidence of bridging nitrate ligands in octahedral ammine complexes. In fact, the only other crystal structures of ammine complexes containing nitrates as ligands are the copper nitrate di-and monoammines [14] and platinum diammine dinitrate [15], where the nitrate and ammonia ligands are coordinated to the metal centres in a square planar geometry. Unlike these copper and platinum compounds, which achieve three-dimensional connectivity through hydrogen bonds, Ni(NH 3 ) 2 (NO 3 ) 2 is connected in all three dimensions via bridging nitrate anions.…”