Synthesis, Crystal Structure, Magnetism, Band Structure and Density of States of [C6H18N3]ClCoCl4

• DOI: 10.1007/s10948-012-1469-5
• Publication Date: 2012-02-04T05:08:37Z
• Authors: F. Issaoui; I. Baccar; E. Dhahri; O. El Sadek; F. Zouari; E. K. Hlil
• Keywords: Monoclinic crystal system; Magnetism

The crystal structure of [1-(2-aminoethyl) piperazinium] choride trachloridocobaltate (II): [C6H18N3] ClCoCl4 has been synthesized and analyzed by X-ray diffraction. Magnetization was used to investigate the magnetic properties. The salt crystallizes at room temperature in the monoclinic system with space group P21, the unit cell dimensions are: a=7.2113 A, b=12.4844 A, c=8.0554 A, β=97.274∘ with Z = 2. The crystal structure of this salt was solved by Patterson methods and refined by full-matrix least squares on F 2 to final values of R=0.0361 and wR=0.0701. The structure consists of monomeric triprotonated [1-(2-aminoethyl) piperazinium] cations, monomeric $\mathrm{CoCl}_{4}^{2-}$ and Cl− anions. These entities are interconnected by means of hydrogen bonding contacts forming a three-dimensional network. The magnetic measurements experimentally show a deviation from the Curie–Weiss law at low temperatures, which reveals the occurrence of weak ferromagnetism at low temperature. The measurements of isothermal magnetics at low temperature show a weak hysteresis, which was confirmed by the small coercive field found at low temperature. In addition, self-consistent ab initio calculations, based on FLAPW method (Wien2k code), are performed to investigate magnetic, electronic properties and crystal structure, of [1-(2-aminoethyl) piperazinium] choride trachloridocobaltate(II). Spins polarized within the framework of the Coherent Potential Approximation (CPA) are considered.