Metal nitrato complexes

The decay of LMOONO, generated either as in Eq. (36), or by substitution of peroxynitrite into a metal complex, is usually written as a homolytic process of Scheme 9. The LMO and N02 so generated can then either diffuse apart or recombine within the solvent cage to either regenerate the peroxynitrito complex or form the metal-nitrato intermediate, followed by release of free nitrate by hydrolysis. At the time we initiated the work described below, there were no clear examples of LMOONO species isomerizing to a metal nitrato complex, although such reactions have been considered as a possibility (180-182). 

N2O4 has been extensively studied as a nonaqueous solvent system and it is uniquely useful for preparing anhydrous metal nitrates and nitrato complexes (p. 468). Much of the chemistry can be rationalized in terms of a selfionization equilibrium similar to that observed for... 

The sulfato and nitrato triphenylphosphine complexes were also obtained by the reaction of sulfuric or nitric acid with [Pd(PPh3)4] in ethanol.132 Nitrato complexes can also be prepared by isolation of [Pd(N03)2(H20)2], obtained by dissolution of Pd metal in concentrated nitric acid,133,134 and subsequent reaction with ligands L (e.g. L2 = 2,2 -bipyridyl).135 A crystal structure determination has been carried out for the complex cis-[Pd(N03)2(DM50)2].136... 

Because of the higher charge and polarizing power of Ce4+ ion the metal-oxygen bond distances in its complex are shorter than the M-O bond distances in the Ce(III) nitrato complex. 

B. P. Hay, Inorg. Chem., 30, 2876 (1990). Extension of Molecular Mechanics to High-Coordinate Metal Complexes. Calculation of the Structures of Aqua and Nitrato Complexes of Lanthanide(III) Metal Ions. 

The results of solid state reactions of protactinium dioxide and pentoxide with other metal oxides (89, 93-96) support the view that the oxide systems of protactinium resemble those of other actinide elements rather than those of niobium and tantalum. However, when assessing results of this type one must always bear in mind the relative ionic radii of the respective M " and M + ions since they obviously play a large part in determining the structures of the complex phases. This comment applies equally well, of course, to the structural properties of other types of compound and in particular to the high coordination numbers exhibited by protactinium(V) in its chloro and nitrato complexes. 

The HNO3 dependencies of the extraction of U(VI) and Th(IV), shown in Figure 4, should be considered of operational significance only since several parameters vary simultaneously as the equilibrium aqueous HNO3 concentration is varied. For example, NOl activity and nitrato complexing of metals in the aqueous and the free extractant concentration in the organic phase may vary as the aqueous HNO3 concentration is varied. 

Metal nitrates and nitrato complexes. There are several groups of compounds in which the NO3 group is directly bonded to one or more metal atoms by bonds which presumably have considerable covalent character, namely ... 

NO2 adds to oxo complexes such as Cr02 +, 205 [(TMPS)FeIVO],20 and MbI e,vO to form nitrato complexes. 203 It adds reversibly to CrOO2 + to form a rather unreactive peroxynitrato complex.208 These reactions lead to the reduction of the metal center and thus can be considered as good examples of the inner-sphere electron transfer mechanism. 

Et4N][N03] functions as a base in liquid N2O4 and its action on metals such as Zn and A1 arises from the formation of nitrato complexes (equation 8.74) analogous to hydroxo complexes in an aqueous system Figure 8.6 shows the structure of [Zn(N03)4]. ... 

The structures and vibrational spectra of a large number of nitrato complexes have been reviewed by Addi n et and Rosenthal. X-ray analyses show that the NO3 ion coordinates to a metal as a unidentate, symmetric and asymmetric chelating bidentate, and bridging bidentate ligand of various... 

The use of far-infraired spectra to distinguish unidentate and bidentate nitrato coordination has been controversial. Nuttall and Taylor " suggested that unidentate and bidentate complexes exhibit one and t vo MO stretching bands, respectively, in the 350-250 cm" region. Bullock and Parrett sho ved, however, that such a simple rule is not applicable to many known nitrato complexes. Ferraro and Walker assigned the MO stretching bands of anhydrous metal nitrates such as Cu(N03)2 and PrCNOa),. 

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