Crystal growing of [Fe(3-bpp)2]Cl2.6.5H2O complex
Fitriani (a,b), Djulia Onggo (a), Irma Mulyani (a*), M. Abdulkadir Martoprawiro (a)

a) Inorganic and Physical Chemistry Research Group
Faculty of Mathematics and Natural Sciences
Institut Teknologi Bandung, Jl. Ganesha 10 Bandung 40132 Indonesia
b) Department of Chemistry Education, Universitas Muhammadiyah Pontianak
Jl. Ahmad Yani 111 Pontianak 78123 Indonesia

*imulyani[at]itb.ac.id

Abstract

The bis 2,6-bis(pyrazo1-3-y1)pyridine (3-bpp) of iron(II) complexes ([Fe(3bpp)2]2+) have been intensively investigated since exhibiting Spin Crossover (SCO) properties that depend on the ligand field strength and also the counter anion type. Generally, the [Fe(3-bpp)2]A2 complexes with various counter anions (A) were prepared by replacing the chloride anion of [Fe(3-bpp)2]Cl2 with other counter anions, using their sodium or potassium salts. The chloride anion is usually easy to be replaced by other counter anions. In the previous report, the [Fe(3-bpp)2]Cl2 6.5H2O complex was surprisingly isolated from the reaction of [Fe(3-bpp)2]I2 with excess silver chloride by agitation method. The iodide was replaced successfully by the chloride anion and the structure was solved perfectly. As a result of our study, the replacement of the chloride anions from the [Fe(3bpp)2]Cl2 complex by the [Ni(CN)42&#61485-] anions was observed in the solid product of [Fe(3bpp)2]Ni(CN)4, which was obtained from the reaction between the [Fe(3-bpp)2]Cl2 dan K2[Ni(CN)4] solutions. However, crystals of [Fe(3-bpp)2]Cl2 were grown perfectly from solution filtrate which was the remaining solution of that reaction. To confirm this finding, we prepared the mixture of aqueous methanolic solutions of FeCl2 and 3-bpp ligand without the addition of K2Ni(CN)4 solution. Single crystals of [Fe(3-bpp)2]Cl2 were obtained in reasonable amounts.

Keywords: Iron(II) complexes, 2,6-bis(pyrazol-3-yl)pyridine, chloride anion

Topic: CHEMISTRY AND MATERIAL SCIENCES