Palladium complexes cyclopentadienyl

Deprotonation with aluminum alkys, 9, 272 mononuclear carbonyl iridium complexes, 7, 302 for palladium cyclopentadienyl complexes, 8, 390 in Ru and Os half-sandwich preparations, 6, 569 in silver carbene synthesis, 2, 206 Desulfurization... 

C,Hj, Acetic acid palladium complex, 26 208 tungsten complex, 26 224 02CiH(, 2-Propenoic acid, methyl ester platinum ester, 26 138 02C4Hu, Ethane, 1,2-dimethoxy-solvates of chromium, molybdenum, and tungsten carbonyl cyclopentadienyl complexes, 26 343 tungsten complex, 26 50 ytterbium complex, 26 22 02C4Hi, -NaCsHs, Ethane, 1,2-dimethoxy-compd with cyclopentadienylsodium(l l), 26 341... 

The types of compounds formed by gold(I) and gold(III) often differ from those of other metals due to the constraints imposed by coordination number and electron count at the metal. Thus, for example, whereas 7r-bonded cyclopentadienyl complexes of palladium and platinum are numerous (336), and a copper(I) species of this type is known (337), cyclopentadienyl complexes of univalent (94, 96, 97) and trivalent (228) gold have invariably been found to be fluxional behavior, similar to that in dicyclopentadienylmercury, was involved (228). 

Cycloalkenes, into if-allyl palladium complexes, 8, 363 Cycloalkenyl rings, metal complex conformational interconversions, 1, 414 Cycloalkynes, in nickel complexes, 8, 147 (Cyclobutadiene)cyclopentadienyl complexes, with cobalt, polymercuration, 2, 435 Cyclobutadienes... 

O4M02PC23H29, Molybdenum, tetracarbonyl-bis(Ti -cyclopentadienyl)(p,-di-tert-butyl-phosphido)- jL-hydrido-di, 25 168 Oghl4CioFIi23 Xanthosine palladium(II) complexes, 23 54... 

C.i. a- and 77-Bonded Complexes of Palladium 7T-Allyl and Cyclopentadienyl Complexes... 

The Group VIII cyclopentadienyl complexes of formula CpM(NO) (M = Ni, Pd, Pt) have all been synthesized. The nickel complex is best prepared from nickelocene and nitric oxide, and a method for the preparation of the nickelocene m situ without its isolation has been described (56). The palladium complex can be prepared from [Pd(NO)Cl] and sodium cyclopentadienide (23) and the platinum complex from Pt2(CO)2Cl4 and sodium cyclopentadienide and nitric oxide (22). The microwave (13) and infrared spectra (18) of CpNi(NO) have received detailed study, and the electronic structure of the complex is discussed in an early paper (77). 

New 7 -cyclopentadienyl complexes of palladium have been synthesized following common preparative routes already discussed in COMC (1982) and COMC (1995). Many of these complexes just use cyclopentadienyl as an auxiliary ligand to synthesize complexes where the interest is in the other ligands bound to palladium, or in the complete shape of the molecule as in liquid crystal design. "" ... 

Ligand-substitution reactions (or nucleophilic attack at the metal) in cyclopentadienyl complexes of palladium have been used to prepare new derivatives. The classical introduction of a cyclopentadienyl moiety by use of TlCp or NaCp and a cationic or halo palladium complex has been employed in the synthesis of complexes [Pd( 7 -Cp)(dppe)]Tf " and PdCp 3-(CHO)C6H3C(H)=NCy. A novel route has been applied that involves deprotonation of cyclopentadiene by a coordinated hydroxyl group to afford the cyclopentadienyl complexes shown in Equation (63). ... 

Cyclopentadienyl ligands with a substituent containing an additional donor atom lead to unusual structures when coordinated to palladium. The complex of composition Pd(C5Me4CH2CH2NMe2)(J7 -allyl) has been prepared, and both the Cp ring and phosphorus coordinate to palladium in the dimeric complex shown 104, whose molecular structure was determined by X-ray diffraction methods. It was synthesized by reaction of Tl(Cp-PPh2) with PdClMe(COD). ... 

The reaction of palladium indenyl complexes with isonitriles leads to the synthesis of palladium fulvenes (Scheme 86). The reaction seems to occur by decoordination of the indenyl fragment, and the resulting indenide attacks a coordinated isonitrile. An analogous reaction takes place when cyclopentadienyl is used. ... 

A second one-step synthesis of ferrocene is achieved by the direct action of metal halides on cyclopentadiene in the presence of a base such as di- or tri-ethylamine. This method also can be applied to the preparation of cobalt, nickel, copper, and palladium cyclopentadienyl 7r-complexes, although the yields with these metals are not as high as with iron. 

The first metal-olefin complex was reported in 1827 by Zeise, but, until a few years ago, only palladium(II), platinum(Il), copper(I), silver(I), and mercury(II) were known to form such complexes (67, 188) and the nature of the bonding was not satisfactorily explained until 1951. However, recent work has shown that complexes of unsaturated hydrocarbons with metals of the vanadium, chromium, manganese, iron, and cobalt subgroups can be prepared when the metals are stabilized in a low-valent state by ligands such as carbon monoxide and the cyclopentadienyl anion. The wide variety of hydrocarbons which form complexes includes olefins, conjugated and nonconjugated polyolefins, cyclic polyolefins, and acetylenes. 

In 1971 only two complexes of palladium(I) had been identified.65 Although the area has grown significantly, the relative paucity of palladium cluster compounds can be attributed, in part, to the surprising weakness of palladium-carbon monoxide bonds and in particular those where CO is bound terminally. In this chapter the chemistry of palladium(I) and clusters of palladium in other oxidation states will be considered. However, complexes containing organic ligands such as allyl and cyclopentadienyl will not be dealt with as this area has been reviewed recently in a companion volume.66... 

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