Ruthenium complexes hydrazines

HjNiOcjOsjCuHs, Osmium, nonacarbonyl-( tl -cyclopentadienyl )tri- x-hydridonickeltri-, 26 362 H,NiO,Ru,C14H5, Ruthenium, nonacar-bonyl-f-rf-cyclopentadienyl)-tri-p.-hydridonickeltri-, 26 363 H4N, Hydrazine ruthenium(II) complexes, 26 72 H40 20sjCi , Osmium, dodecacarbonyl-tetra- x-hydrido-te/rahedro-tetra-,... 

N-nitrosation and an interesting Fischer-Hepp rearrangement to the C-nitroso isomer (Bowden et ai, 1976). Hydrazine hydrate reacts with the diarsine ruthenium complex [Ru(das)2(NO)CI]Cl2 yielding the corresponding azide complex (29) which represents another example of electrophilic nitrosation... 

The ruthenium complex Ru[Ph2P(E)NP(E)Ph2-5c,5e ]Pph3 (55b) has been reported to react with pyridine, SO2, NH3 and hydrazines, forming complexes which obey the 18 electron rule. The reaction (55b) with pyridine yields the kinetic trans-isomer (56), which in solution slowly isomerizes to the thermodynamic cis-isomer. For the reaction of (55b) with SO2 both isomers of (57) are present in the reaction mixture. This is in contrast with the reaction of (55a) with SO2, where only the cis-isomer could be isolated. Both the sulfur and selenium analogues of (55) react with NH3 and hydrazines to a mixture of cis-and trans-isomers of (58) and (59), respectively. ... 

Complex formation with flic substrate is the key stage of many catalytic processes. The formation of the following types of organometallic complexes is most typical in catalysis alkyl 7i-complexes, carbene complexes, n-complexes of substrates with the saturated bond (olefin, acetylene and allyl, complexes with carbon oxides), hydrazine complexes, and complexes with molecular oxygen and nitrogen. The structure of a ruthenium complex with CO2 obtained on the basis of an ab initio study is presented in Fig. 17.4. 

Historically, the most important ruthenium(II) ammine species is [Ru(NH3)5N2]2+, the first stable dinitrogen complex to be isolated (1965). It was initially obtained by refluxing RuC13 in hydrazine solution (but many... 

The formation of a ruthenium vinylidene is proposed as the key intermediate in the regioselective addition of hydrazine to terminal alkynes [55]. This reaction, which proceeds via addition of the primary amino group of a 1,1-disubstituted hydrazine followed by deamination, provides an unprecedented access to a variety of aromatic and aliphatic nitriles. The tris(pyrazolyl)borate complex RuCl(Tp)(PPh3)2 gave the best catalytic activity in the absence of any chloride abstractor (Scheme 10.17). 

The first dinitrogen complex, characterized in 1965, resulted From the reduction of commercial ruthenium trichloride [containing some Ru(lV)] by hydrazine hydrate. The pentuammine(dinitrogen)ruthenium(Il) cation that formed could be isolated in a variety of salts.50 Soon other methods were found to synthesize the complex, such as the decomposition of the pentaammineazido complex, [Ru NH3)3N,Jj+, and even direct reaction with nitrogen gas ... 

Dalzin (bis(allylthiocarbamido)hydrazine) forms sparingly soluble complexes (29) in which it is bonded through sulfur and nitrogen atoms (Section 10.2.7) but the bright orange-red bismuth complex can be extracted into chloroform for a spectrophotometric determination provided cyanide is present to mask copper. 1,4-Diphenylthiosemicarbazide PhNHNC(SH)NHPh can be used for the spectrophotometric determination of ruthenium after extraction of its violet-red complex into chloroform. 

Ruthenium(III) chloride (2.0 g., 9 mmoles) (free from nitrosyl impurities) is dissolved in water (10 ml.) in a 200-ml. beaker. Hydrazine hydrate (85%, 20 ml.) is added carefully to the well-stirred solution. The initial reaction is exothermic, and large quantities of gas are evolved. The solution is stirred for about 12 hours and filtered by gravity. Because of the vigorous evolution of gas and the highly exothermic nature of the initial reaction, it is not recommended that the scale of the reaction be increased. Chloro complexes such as (NH<)2[RuClt] or K2[RuC15H20] may be substituted for ruthenium (III) chloride. 

The preparation of the hexaammine complexes of ruthenium(II) and ruthenium (III) salts are sketchily described in the literature. The preparation of hexaammineruthenium(II) by the reduction of ruthenium trichloride with zinc in ammonia is described briefly by Lever and Powell.1 Allen and Senoff2 carry out the reduction using hydrazine hydrate. The hexaammineruthe-nium(III) cation is obtained by oxidation of the ruthenium(II) complex,1 and pentaamminechlororuthenium(III) dichloride is obtained by treating the former compound with hydrochloric acid.1,3 This compound may also be obtained by treating the pentaammine molecular nitrogen complex of ruthenium(II) with hydrochloric acid.2,4... 

Ruthenium(II) The synthesis of [Ru(NH3)5N2]2+ was first prepared in 1965 by refluxing RuCl3 in aqueous hydrazine.310 Since then a range of methods have been developed for the synthesis of this complex. Scheme 9 summarizes the main routes to [Ru(NH3)5N2]2+. 

The common metathesis reactions for the preparation of metallocenes, treating a metal salt MX2 with NaCp, are hampered in the case of ruthenium by the lack of suitable Ru salts. (Rul2 is commercially available, but is still not commonly used in the synthesis of rathenocene.) Thus, ruthenocene has been obtained from Ru(acac)3 and NaCp in very low yield and later from RuCb and NaCp in 50-60% yield. It has now become apparent that alkene polymers, in particular [Ru(nbd)Cl2]x, but also [Ru(cod)Cl2]x and hydrazine derivatives (Section 3.1), can serve as Ru precursors. Equally successful in many cases is reductive complexation of cyclopentadiene in ethanol in the presence of Zn (Section 3.2), which furnishes the metallocene in about 80% yield. Decamethylruthenocene (82) was first obtained by the Zn reduction route in 20% yield, but can now be prepared conveniently from halide complexes [Cp RuCl2]2 or [Cp RuCl]4, a common method for the preparation of symmetrical and unsymmetrical sandwich compounds of ruthenium featuring one alkyl-substituted ligand. 

Cyano-derivatives can be readily obtained by a ruthenium-catalyzed addition of various hydrazines to terminal alkynes [89] in which the cyano carbon atom arises from the terminal alkyne carbon atom. The tris(pyrazolyl)borate (Tp) complex RuCl(Tp)(PPh3)2 (1 mol%) was found to be the most active catalyst, and N,N-dimethylhydrazine (5 equiv.) the best nitrogen source. The proposed mechanism involves the nucleophilic attack of the nitrogen nucleophile on the a-carbon of a vinylidene intermediate (Scheme 8.27). Proton migration in the resulting a-hydrazi-nocarbene, followed by deamination, would give the nitrile derivative and regenerate the catalytic species. 

H5N2C, Hydrazine, methyl-, ruthenium(II), complexes, 26 72 H,B , Diborane(6), 27 215 HftMoPiCyHw), Molybdenum(IV), hexahy-dridotris(tricyclohexylphosphine)-, 27 13... 

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