Die Kristallstrukturen von trans‐[NiBr2(Pyridin)4] und [Ni(HNPEt3)4]I2

Crystal Structures of trans ‐NiBr₂(pyridine)₄] and Ni(HNPEt₃)₄]I₂ Turquoise single crystals of trans‐NiBr₂(pyridine)₄] have been obtained by the reaction of excess pyridine with nickel(II) bromide/diacetonealcohol. According to the crystal structure determination the nickel atom is octahedrally coordinated by the two bromine atoms in trans‐position and by the nitrogen atoms of the pyridine molecules. Space group Pna2₁, Z = 4, lattice dimensions at 20 °C: a = 1592.9(2), b = 943.8(1), c = 1413.0(2) pm, R₁ = 0.0492. Dark blue single crystals of the phosphoraneimine complex Ni(HNPEt₃)₄]I₂ have been obtained from NiI₂/H₂O with excess Me₃SiNPEt₃ and subsequent recrystallization from acetonitrile. According to the crystal structure determination the nickel atom is tetrahedrally coordinated by the nitrogen atoms of the HNPEt₃ molecules. The iodide ions are connected via N–H…I contacts with the cation to form an ion triple. Space group P2₁/c, Z = 4, lattice dimensions at –80 °C: a = 1934.9(2), b = 1078.3(1), c = 1966.3(2) pm, β = 111.040(8)°; R₁ = 0.043.