Ruthenocenes synthesis

Cyclopentadienyl rings, in chromocenes with heteroatom substitutions, 5, 330 with pentalene rings, 5, 331 with substitutions, 5, 329 Cyclopentadienyl ruthenocenes, synthesis, 6, 639 Cyclopentadienyl—silylamido complexes, with Zr(IV) and Hf(IV) and monodentate ligands, 4, 852 Cyclopentadienyl—silylamido dienes, with Zr(IV) and Hf(IV),... 

Synthesis of ruthenocene from fission-product ruthenium isotopes was done by neutron irradiation ofU30g and FeCpj powder mixtures. It was shown that most of the ruthenocene found was actually produced by the decay of a precursor. Subsequent knowledge makes it apparent that the fission product recoils formed a rhodium dicyclopentadienide whose structure was preserved through the decay . The total yield of ruthenocene reached a value of 60% under some experimental conditions and was rarely less than 40%. 

A similar synthesis of ruthenocene was done by neutron irradiation of FeCp2 and RUO2 powders together. The yield of RuCp2 was, however, extremely low (0.01 %)37).38>. K ,... 

In connection with j8-decay synthesis, the synthesis of organometallic compounds as a consequence of nuclear fission must be mentioned 9-11, 13). In this way, for example, a powdered mixture of Fe(CjH5)2 and UsOg gives good yields of ruthenocene (10) and iodoferrocene (9) on fission. 

In a more detailed study of this reaction, Rausch, Vogel, and Rosenberg determined optimum conditions for the synthesis of either XXVII or XXVIII (90). Ruthenocene has also been mercurated using glacial acetic acid as the solvent, but pure products could not be separated (88). 

Pigeon P, Top S, Vessieres A, Huche M, Hillard EA, Salomon E, Jaouen G (2005) Selective estrogen receptor modulators in the ruthenocene series. Synthesis and biological behavior. J Med Chem 48 2814-2821... 

Synthesis and application of 103Ru-labelled ruthenocene compounds 1240... 

The mercuration of metallocenes has continued to attract interest due to the potential use of the mercurated species in the synthesis of different metallocene derivatives. New mercurometallocenes, together with some mechanistic studies on their formation,have been reported over the past few years. Besides the monomercurated species, a detailed study has appeared on the permercuration of ferrocene and ruthenocene. For both metallocenes, the decamercurated species shown in equation (7) have been obtained in high yields. 

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. 

The research on ferrocene-containing thermotropic liquid crystals has concentrated, so far, on design, synthesis, and investigations of thermal properties. These efforts, and more particularly the results obtained, could be a source of inspiration for the development of new metallomesogens. As an example, we recently reported the first liquid crystalline ruthenocene derivatives [29]. 

A convenient synthetic route to [CpRu (CH3CN)3]PF6. Organometallics, 21, 2544-2546 Kiindig, E.P. and Monnier, F.R. (2004) Efficient synthesis of tris (acetonitrile)-(r 5-cyclopentadienyl)-ruthenium(II) hexafluorophosphate via ruthenocene. Advanced Synthesis e[ Catalysis, 346, 901-904. 

Photo-oxidation of ferrocene by CCI4 in solution can normally only be effected by u.v. irradiation. However it has been observed that the reaction may be carried out with visible light in cetyltrimethylammonium chloride micelles, albeit with low quantum yield.It is suggested that the main effect of micellization may be an increase in the oxidation potential of ferrocene or alternatively that a CTTS state of ferrocene is involved under these conditions. The ring substitution of ruthenocene by irradiation in 1 1 (v/v) solutions of ethanol with CCI4, CHCI3, or CH2CI2 proceeds by a mechanism similar to that previously found for ferrocene. Other reports consider the synthesis of ferrocenyl thioesters and the photooxidation of ferrocene. ... 

Open ruthenocenes, Ru rj -CsRj)2, with asymmetric substitution of the pentadienyl ligands (see Pentadienyl Ligand) allow for the synthesis of diastereomeric products. The treatment of (1) with 2-methyl-4-phenylpentadiene and zinc dust yielded bis(2-methyl-4-phenylpentadienyl)ruthenium (94). The product consists of a pair of diastereomers, which were easily separated by fractional crystallization because of their substantially different solubilities. One isomer could exist as a pair of enantiomeric rotamers, each with Ci symmetry (94a) and (94b), while the other could be a pair of diastereomeric rotamers, both with C2 symmetry (94c) and (94d). Both of the former rotamers are observable, but (94c) is the only form of the latter, and interconversion to (94d) does not occur. The possibility of isomerization with photochemical initiation still remains to be investigated. ... 

The earliest and most well-developed route to polyphosphazenes involves the thermal ROP of cyclic phosphazenes bearing halogen substituents at phosphorus. Use of this method and subsequent halogen replacement with alkoxides has led to the synthesis of ferrocene- and ruthenocene-containing polyphosphazenes 31 and 32 with molecular weights (d/w) in excess of 2 x... 

Langa et al. [38] described the first synthesis of D-A dyads (30a-c) based on C o and used ruthenocene as the electron-donor fragment (Scheme 21.12). Synthesis of these pyrrolidine)60]fullerene systems was achieved by 1,3-dipolar cycloaddition of ruthenocenecarboxaldehyde (28), N-methylglycine, and C o in toluene under the action of microwave irradiation in a focused microwave oven. The adducts 30a-c were obtained in moderate yields (26-31%). 

Scheme 2.5 Synthesis of Ru-ruthenocene 32 from ferrocene derivative 31.

Recoil implantation was first performed by Baumgartner and Reichold (1961) for fission recoil synthesis of ruthenocene. This technique was applied to the synthesis of new compounds of technetium phthalocyanine (Yoshihara et al. 1974b) and Tc(II)(acac)2 (Sekine and Yoshihara 1981). In the latter case, sublimatographic separation was effectively employed (O Fig. 24.19). 

Chemical synthesis from stable components/ Single crystal in ruthenocene... 

The condensation of respective l,r-bis(chlorocarbonyl)-metallocenes (1) and (2) [9, 10] with p-tert-butylcalix[4]arene [11] (3) in the presence of triethylamine gave, after column chromatography (alumina/CH2Cl2), the ferrocene calix[4]arene (4) (64% yield, orange crystals) and the ruthenocene analogue (5) (47% yield, pale yellow crystals) (Scheme 1). The structures of both new air-stable metallocene calix[4]arenes were verified by elemental analysis and mass spectrometry. The experimental details for their synthesis and characterisation will be reported elsewhere. 

The synthesis of vinylruthenocene VR and vinylosmocene VO requires acetylation, reduction and dehydration by pyrolysis from alumina (Scheme 2), The procedure of Hill and Richards was used rather than more conventional acetylation with acetyl chloride and aluminum chloride because it gave near quantitative yield of acetylruthenocene with no formation of 1,1 - diacetylruthenocene In the case of osmocene acetylation is only 70-80% complete. Increasing the reaction time produces extensive decomposition. Thus chromatography is required to remove the tar formed and to separate osmocene and acetyl-osmocene. In general higher temperatures and longer reaction times are required for osmocene as compared to ferrocene and ruthenocene, in agreement with previous observations. 

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