S. Geremia, N. Demitri
Mar 1, 2005
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Influential Citations
39
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Journal
Journal of Chemical Education
Abstract
An advanced undergraduate crystallographic experiment is proposed that integrates the well-tested protocol for synthesis of manganese acetylacetonate, Mn(acac)3, with a new low-temperature characterization of the crystal structure of the synthesized complex. Standard synthesis of Mn(acac)3 was followed by crystallization trials to obtain single crystals suitable for X-ray structural determination. Surprisingly, single crystals of a new crystalline form (δ) were obtained. When cooled to 100 K, single crystals of the δ form underwent an irreversible solid–solid phase transition to another new form (e). The discovery of these new crystalline forms was a highly stimulating experience for the students involved. The goal to investigate the Jahn–Teller behavior of the high-spin Mn(III) complex, Mn(acac)3, was more than successfully achieved with the recognition of an unusual orthorhombic distortion (OD) of the coordination polyhedron. This experiment not only introduces crystallography, one of the most powerful ...