Décacarbonyle de dimanganèse

Dimanganese decacarbonyl, which has the chemical formula Mn2(CO)10, is a binary bimetallic carbonyl complex centered around the first row transition metal manganese. The first reported synthesis of Mn2(CO)10 was in 1954 at Linde Air Products Company and was performed by Brimm, Lynch, and Sesny. Their hypothesis about, and synthesis of, dimanganese decacarbonyl was fundamentally guided by the previously known dirhenium decacarbonyl (Re2(CO)10), the heavy atom analogue of Mn2(CO)10. Since its first synthesis, Mn2(CO)10 has been use sparingly as a reagent in the synthesis of other chemical species, but has found the most use as a simple system on which to study fundamental chemical and physical phenomena, most notably, the metal-metal bond. Dimanganese decacarbonyl is also used as a classic example to reinforce fundamental topics in organometallic chemistry like d-electron count, the 18-electron rule, oxidation state, valency, and the isolobal analogy. Many procedures have been reported for the synthesis of Mn2(CO)10 since 1954, the two most common general types are discussed herein. Some of these methods were not designed to create Mn2(CO)10, but rather treat Mn(I), Mn(II), or Mn(-I) as an oxidizing or reducing agent, respectively, for other species in the reaction, but produce Mn2(CO)10 nonetheless. The carbonylation route involves the reduction of a Mn(I) or Mn(II) salt to the Mn(0) species in concert with carbonylation to a coordinatively saturated metal center with CO gas. The carbonylation using CO can be under heightened pressures of CO, relative to atmospheric pressure, or at ambient pressure. Examples of each are given. As previously mentioned, Mn2(CO)10 was first prepared in 1954 by Brimm, Lynch, and Sesny, albeit in yields of ~1%, by the reduction of manganese(II) iodide with magnesium(0) under 3000 psi (~200 atm) of carbon monoxide (CO). The balanced reaction is represented by:2 MnI2 + 2 Mg + 10 CO -> Mn2(CO)10 + 2 MgI2A more efficient preparation was developed in 1958 and entails reduction of anhydrous manganese(II) chloride with sodium benzophenone ketyl radical under similarly high pressures (200 atm) of CO.