Carbon monoxide ligands hydrogen bonds

In some cases during HCHO reduction, the same products are formed as in the reaction of carbon monoxide with hydrogen. This confirms the formation of formaldehyde from carbon monoxide in the intermediate stage.The breaking of the C — O bond may occur as a result of elimination of the water molecule from coordinated hydroxycarbene and hydroxymethyl ligands " see equations (13.209) and (13.210). A radical mechanism for carbon monoxide reduction is proposed for reactions... 

Formally, the lone pairs on molecular nitrogen, hydrogen cyanide, and carbon monoxide are sp hybrid orbitals, whereas NLMO hybridizations calculated even lower p contributions. Hence, these lone pairs have low directionality, the electron density remains close to the coordinating atom and interaction between the lone pair and the Be2+ is comparatively weak. The Be-L bonds are easily disrupted and ligand exchange consequently can proceed with a low activation barrier. A high degree of p character, on the other hand, means that the lone pair is directed toward beryllium, with electron density close to the metal center, and thus well suited for coordination. 

The dark red crystalline compound C ELCosOa formed by treating dicobalt octacarbonyl with acetylene, carbon monoxide, hydrogen, and isopropyl alcohol (57) may have a similar structure, i.e., (LXVIII R = allyl and one CO ligand replaced by the C=C bond of the allyl group). 

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