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

The crystal structure of [1-(2-aminoethyl) piperazinium] choride trachloridocobaltate (II): [C 6 H 18 N 3 ] ClCoCl 4 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 P2 1 , the unit cell dimensions are: a =7.2113 Å, b =12.4844 Å, c =8.0554 Å, 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 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.