Crystal structure, vibrational studies and optical properties of a new organic-inorganic hybrid compound (C₁₀H₂₈N₄)CuCl₅Cl⋅4H₂O.

A new organic-inorganic hybrid material, 1,4-bis(3-ammoniumpropyl) piperazinium pentachloridocuprate(II) chloride tetrahydrate [(C₁₀H₂₈N₄)CuCl₅Cl⋅4H₂O], has been synthesized and characterized by X-ray diffraction, UV-visible absorption, Infrared and Raman spectroscopy. The compound crystallizes in the orthorhombic system and Pnma space group with a=8.18 (3)Å, b=10.96 (5)Å, c=21.26 (9)Å, V=2254.3 (15)Å(3). In this structure, the Cu(2+) ion, surrounded by five chlorides, adopts the square pyramidal coordination geometry. The structure of this compound consists of tetraprotonated 1,4-bis(3-ammoniumpropyl) piperazinium cations and the anionic sublattice is built up of isolated, square pyramid [CuCl₅](3)(-) units, chloride ion Cl(-) and water molecules connected with each other by hydrogen bonds. Organic and inorganic entities are interconnected by means of hydrogen bonding contacts [NH⋯O(Cl), O(W)H⋯Cl and O(W)H⋯O]. Furthermore, the room temperature IR and Raman spectra of the title compound were recorded and analyzed on the basis of literature data. The optical study was also investigated by UV-Vis absorption. In fact, the organic-inorganic hybrid crystal thin film can be easily prepared by spin-coating method from the ethanol solution of the (C₁₀H₂₈N₄)CuCl₅Cl⋅4H₂O hybrid compound and it showed absorptions characteristics of CuCl based layered compounds centered at 275 and 374 nm.