Dimanganese decacarbonyl structure

Fig. 75.6 Alternative structures for dimanganese decacarbonyl and dicobalt octacaiboryl. Structure (a) is unknown, but there is infrared evidence for the existence of (b) in solution.

Dimanganese decacarbonyl, which is prepared by the reduction of manganese(II) halide in the presence of carbon monoxide under pressure [3], is a yellow crystalline, air-stable solid soluble in organic solvents, which sublimes readily in vacuo at ca 50 °C. A single-crystal X-ray diffraction study showed that Mn2(CO)io possesses the structure as shown below. 

The structure of vanadium carbonyl is again different from those of dimanganese decacarbonyl or dicobalt octacarbonyl. Despite an early report... 

The structure of dimanganese decacarbonyl can be explained using d sp hybridization, as shown in Figure 16. Out of the six hybrid orbitals on each manganese atom, five orbitals accept a lone pair of electrons from the carbon monoxide molecules to form 10 Mn<—CO coordinate bonds. While, the remaining one half-filled orbital on each manganese overlap to form a Mn—Mn bond. 

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