Über die Darstellung und die Kristallstruktur der Komplexverbindungen Ni(py)4F2 · 2H2O und Cu(py)4F2 · 1,33 HF · 2H2O

Abstract

Abstract Single crystals of Ni(py)4F2 · 2H2O (1) and Cu(py)4F2 · 1.33 HF · 2H2O (2) have been synthesized by solving the precipitated metal fluoride hydrates in Pyridine. Both compounds are sensitive to air. They crystallize in the monoclinic space group C2/c with lattice parameters a = 13.199(2) Å, b = 10.815(2) Å, c = 15.353(2) Å, β = 108.08(1)° for 1 and a = 28.531 (6) Å, b = 8.767(2) Å, c = 17.572(4) Å, β = 104.43(3)° for 2. Within both structures the metal atoms are coordinated in form of a distorted square bipyramid. In the case of 1 four Pyridine nitrogen atoms are in the basal plane and two fluorine atoms in the apical positions. Hydrogen bonding via water molecules lead to infinite chains of Ni(py)4F2 molecules connected by doubly ridged [F2(H2O)2] ring units. In 2 two different complex moieties exist. In one complex two H2O molecules are in the inner coordination sphere besides the four pyridine rings; these molecules are interconnected by two F− ions, which may be partially substituted by HF2 −-groups forming infinite chains along [010]. In the other, HF2 −-ions occupy the apical positions of the square bipyramid around the copper ion. They are linked to the fluoride ions of the chains by weak hydrogen bonds of water molecules arranged in between. Thus, the formula should be better given as [Cu(py)4(H2O)2][Cu(py)4(HF2)2] · F1.66(HF2)0.33 · 2H2O.