Reversible complexation of ammonia by breaking a manganese–manganese bond in a manganese carbonyl ethylenedithiolate complex: a theoretical study of an unusual type of Lewis acid
| Autor: | Luana-Flavia Radu, Radu Silaghi-Dumitrescu, Alexandru Lupan, Amr A. A. Attia, R. Bruce King |
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| Rok vydání: | 2019 |
| Předmět: |
chemistry.chemical_classification
Double bond 010405 organic chemistry Trimethylphosphine chemistry.chemical_element Manganese 010402 general chemistry 01 natural sciences Sulfur Medicinal chemistry Dissociation (chemistry) 0104 chemical sciences Adduct Inorganic Chemistry chemistry.chemical_compound Ammonia chemistry Lewis acids and bases |
| Zdroj: | Dalton Transactions. 48:324-332 |
| ISSN: | 1477-9234 1477-9226 |
| DOI: | 10.1039/c8dt04217a |
| Popis: | The reaction of Mn(CO)5Br with sodium ethylenedithiolate was reported in 1968 to give a dark red binuclear H2C2S2Mn2(CO)6 complex possessing the unusual property of complexing reversibly with ammonia to give a yellow H2C2S2Mn2(CO)6·NH3 adduct. In order to provide some insight into the nature of this adduct, density functional studies were performed on the H2C2S2Mn2(CO)n (n = 4 to 8) systems as well as their relevant ammonia and trimethylphosphine adducts. These theoretical studies support the structure of H2C2S2Mn2(CO)6 originally suggested 50 years ago involving the binding of the ethylenedithiolate C[double bond, length as m-dash]C double bond as well as the sulfur atoms to the Mn2 unit with a bonding Mn-Mn distance of ∼2.8 Å. Complexation of H2C2S2Mn2(CO)6 with NH3 or Me3P preserves the complexed C[double bond, length as m-dash]C double bond of the ethylenedithiolate ligand but lengthens the MnMn distance to a non-bonding ∼3.6 Å. Thus H2C2S2Mn2(CO)6 represents a novel type of Lewis acid where reversible complexation with Lewis bases involves the rupture of a metal-metal bond. Carbonyl dissociation energies in the H2C2S2Mn2(CO)n series account for the formation of the hexacarbonyl H2C2S2Mn2(CO)6 as the stable product from the Mn(CO)5Br/ethylenedithiolate reaction. |
| Databáze: | OpenAIRE |
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