Rhenium -nitrido complexes

The formation of ligands by decomposition of hydrazine or hydrazine derivatives in acidic media provides one of the standard procedures for the synthesis of rhenium nitrido complexes. ... 

Re centers are bridged by an en ligand [22]. Apparently this reaction, which involves displacement of water is not thermally rapid under the synthesis conditions. The study appears to be the first example of photosubstitution of a rhenium-nitrido complex. 

An unusual synthesis of a rhenium(VI) nitrido complex has been observed with the ligand reaction of the rhenium(V) precursor [ReNCl2(PPh3)2] with 2,4,6-tri-isopropylbenzenethiolate, tipt, which gave the green rhenium(VI) complex [ReN(tipt)4], when the reaction mixture was exposed to air, whereas the pale orange rhenium(V) compound [ReN(tipt)4] was obtained in an inert atmosphere. ... 

The reactivity of terminal nitrido ligands towards acidic fragments has been used for the synthesis of imido derivatives starting from the neutral rhenium(V) complex... 

Whereas the oxidation state of the rhenium atom is maintained during the reaction of the potentially tetradentate ligand tris(2-diphenylphosphinoethyl)amine, NP3 (179), with the nitrido complex [ReNCl2(PPh3)2], the rhenium(III) complex [ReCl3( 7 -NPP-... 

Some nitrido complexes of ruthenium, osmium, and rhenium react with phosphines to give phosphineiminato complexes, as shown in Eq. (70). 

In addition to the metal-oxo complexes, several examples of NHC-stabilized rhenium(V)-nitrido complexes exist, e.g., 9 and 10 (Chart 1) [28]. These adducts, which feature triazole-based ligands, were prepared via displacement of phosphine ligands. The stability of both phosphine and triazole-based carbenes in these reactions suggest the nitrido ligand is relatively unreactive. 

Keywords Technetium-99m Rhenium-188 Nitrido complexes Radiopharmaceuticals Imaging Therapy... 

A fairly detailed study has been made of the 1H NMR, far IR and electronic absorption spectral properties of the complexes ReNX2(PEt2Ph)3 (X = Cl, Br or I).325 The characteristic r(Re=N) modes occur close to 1000 cm-1 in the IR spectra of these and other nitrido-rhenium(V) complexes.399,404... 

For rhenium the most important nitrido complexes are those of Rev with general formula ReNX2(PR3)x where the number of PR3 ligands depends on the bulk with PPh3, x = 2, but with PMe2Ph, x = 3. Similar TcNX2(PR3)2 compounds are also known. 

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