Abstract
New compounds (HOOC(CH2)5NH3)2SiF6 (1) and [Cu(Cpl)2(H2O)2SiF6]·2Cpl (2), where Cpl = ε-caprolactam ε-C6H11NO and (HOOC(CH2)5NH3)+ is the 5-carboxypentylammonium ion, were prepared from aqueous solutions and characterized by chemical analysis, IR spectroscopy, and single-crystal X-ray diffraction. In the structure of compound 1, the coordination surrounding of a Si atom is a nearly regular octahedron. The crystals of 1 are triclinic, space group P \(\overline 1 \) . The caprolactam is hydrated and protonated upon crystallization. Hydrogen bonds F…Н–N between \({\text{SiF}}_{6}^{{2 - }}\) anions and organic cations and acidic hydrogen bonds between the carboxy groups of cations were found to exist in the structure of 1. Compound 2 crystallizes in triclinic crystal system, space group P \(\overline 1 \) , and has a chain-polymeric structure. The coordination polyhedra of the two unique copper ions are tetragonally distorted octahedra formed by the O atoms of two Cpl molecules and two F atoms of the hexafluorosilicate ions, which perform as bridges between nearest neighboring cations. The coordination surrounding around a Si atom is a slightly distorted octahedron. Hydrogen bonds between the H atoms of coordinated water molecules and the O atoms of uncoordinated Cpl molecules exist in the structure. The hexafluorosilicate ions in the structures of 1 and 2 have identical geometries.
