Hydrazido complexes chemistry

A general approach to rhenium hydrazido complexes is the reaction of oxo or chloro compounds with organohydrazines as has been demonstrated in an early report with the synthesis of [Re NNC(Ph)0 Cl2(PPh3)2] (310), " the molecular structure of which was solved in 1988. A detailed study on [Re(NNR)Cl2(PPh3)2] complexes with R = COPh or phthalazine shows that the course of subsequent reactions is governed both by the nature of the donor group R responsible for chelate closure and by the type of donor ligand introduced. No simple substitution chemistry has been observed for R = phthalazine. The benzoyl compound... 

Hydrazido(2 —) complexes are most prevalent within group VI although there are to date no reported hydrazido complexes of chromium. Representative examples of known structure are shown in Table 16. Sulfur coligands predominate reflecting the metal-sulfur coordination in nitrogenase and the participation of hydrazide ligands in dinitrogen chemistry. 

There are parallels between the chemistry of imido and hydrazido complexes, mainly because of the common Mo=N- link. Nitrosyl hydrazido complexes are described in Section 5.8. 

Hydrazido(2-) complexes, 2,141-151 bond lengths and angles, 2,145 bridging, 2,150 chemistry, 2,145 electrochemical reduction, 2,147 Group VI, 2,148... 

The aqueous solution chemistry of Tc(VII) is dominated by the stability of the TeO anion [4], Nitrido complexes are few and are limited to peroxides and one dimeric nitrido-hydrazido example. The peroxo complexes based on the [TcVIIN(02 )2] core are analogous to the well-known isoelectronic [MoviO(02)2] complexes [117] and are the only examples of nitridoperoxo complexes and rare examples of peroxo complexes of a metal in the +7 oxidation state. 

A very helpful attempt to classify organohydrazido and related complexes of Group 7 elements by analysis of their X-ray crystal structure data has been undertaken in a review which also covers the structural chemistry of this type of complexes up to the year 1996. The convention applied in this article will also be used here to classify hydrazido and related complexes. 

The chemistry of the hydrazido( 1 -) ligand is in its infancy. Nevertheless, it is clear that such species can, in certain cases, undergo further reactions with protons to release organohydrazine. Whether or not hydrazido(l-) complexes or their organo analogs are capable of yielding an imido complex and an amine in a clean reaction as shown in reaction (58) remains to be demonstrated. 

Reduction of Cp2ZrCl2 with 1.5equiv. of sodium amalgam affords the fulvalene complex CpZr(/r-Cl) 2(/r-C5H4-C5H4) 28.35 COMC(1995) summarized a number of phosphido, sulfide, imido, and alkyl complexes derived from 28. Cuenca and co-workers have since reported further investigations into the chemistry of 28, leading to new zirconium(iv) /(-imido. //-(r/2.r/2-N.N-hydrazido), and //-(r/ -C r/2-C,N-isocyanido) dinuclear fulvalene derivatives.36... 

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