Abstract
Single crystals of 1-methylpiperazine-1,4-diium hexaaquatetrachlorodinickel(II) dichloride, (C5H14N2)[Ni2Cl4(H2O)(6)]Cl-2, were grown by hydrothermal techniques in aqueous solution. The compound was characterised by differential thermal analysis (TG-TDXD), single crystal X-ray diffraction, and variable temperature magnetic susceptibility. The compound crystallizes in the triclinic system (space group P-1, Z = 2) with the following unit cell dimensions: a = 6.611(3) , b = 8.776(4) , c = 17.457(8) , alpha = 101.34(2)A degrees, beta = 96.31(2)A degrees, and gamma = 105.38(2)A degrees. The structure was solved using 4,243 independent reflections and refined to R = 0.024. The structure of (C5H14N2)[Ni2Cl4(H2O)(6)]Cl-2 can be described as mixed organic-inorganic layers along the [-101] direction. The Ni dimers show ferromagnetic exchange (J similar to 15 K), while the interactions between the dimers are antiferromagnetic (J similar to -3 K). The 3D network is further linked by three types of hydrogen bonds (N-H center dot center dot center dot Cl, OW-H center dot center dot center dot Cl, and N-H center dot center dot center dot O), in order to build cation-anion cohesion. Dehydration of the precursor proceeds through three stages, leading to crystalline intermediary hydrate phases and an anhydrous compound.