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Unformatted text preview: Co-ordination Chemistry Assignment1. Briefly show how the Ligand Field Theory (Crystal Field Theory) explains eachof the following observations:(a) [Mn(H2O)6]3+has a magnetic moment of 4.9 BM (4 unpaired electrons) while the moment of [Mn(CN)6]3-is only 2.8 BM (2 unpaired electrons). [Mn(CN)6]3-must be low spin D4, containing 2 unpaired electrons and [Mn(H2O)6]3+is high spin d4, containing 4 unpaired electrons and a larger Δo.(b) [Fe(CN)6]3-is paramagnetic while [Fe(CN)6]4-is diamagnetic.[Fe(CN)6]3-has D5 electron configuration meaning it can have high or low spin, while [Fe(CN)6]4-has D6 electron configuration meaning it can only contain high spin. (c) [NiCl4]2-and [Ni(H2O)6]2+each have two unpaired electrons, but[Ni(CN)4]2-has no unpaired electrons.All the above molecules have a D8 electron configuration which gives 2 unpaired electrons. The addition of cyanide in [Ni(CN)4]2-means a larger splitting of electrons and therefore gives it low spin. Since there is no value for unpaired electrons in D8 low spin, the molecule has no unpaired electrons. 2. What constitutes a heme protein? Draw heme, name three heme proteins and briefly describe their biological tasks, emphasising the role of the metal ion in each case.A heme is a prosthetic group consisting of a central iron atom surrounded by a large organic ring called a porphyrin. There are heme A, heme B, heme C and heme 0....
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- Spring '10
- Jonathon Nguyen, Co-ordination Chemistry Assignment