Nitro Group with the Metal Center

Interaction of the nitro group with the metal center 

In this section we will consider the interaction of the nitro compound with the metal center, but we will not include the reaction of aliphatic nitro compounds when they interact with the metal in their anionic form [20], It is not the purpose of this book to review all of the complexes reported to contain a coordinated organic nitro compound, so only a general outline will be presented. Two reviews have already been published on the coordination chemistry of nitro [21] and nitroso [22] organic compounds, although both of them are now quite old. 

The platinum(II) complex is a catalyst for the hydrc enation of PI1NO2 to PI1NH2 by molecular hydrogen under mild conditions [29], In the rhodium(III) complex v(N02) were observed at 1535-1525 and 1270 cm and it has been considered that the low value for Vs(N02) is evidence for a cyclometallated ortho-nitrophenyl group [30, 31], A mean N-0 bond distance of 1.33(4) A was observed. This should correspond to a remarkable lengthening of N-0 bonds. 

With a metal center ready to donate one electron to the nitro compound, such as manganese in [Mn(CO)s.n(PBu3)n], generated by photolytic or thermal reaction of Mn2(CO)io with PBus, it has been supposed that type (B) coordination leads to the formation of a chelating monoanionic radical (eq. 11) [42]  

These spin adducts have been studied by EPR spectroscopy and they represent interesting examples where the nitroarene is at the beginning of its reduction by the action of the metal center (see also Chapter 6). 

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