Palladium complexes thermolysis

Ruthenium complex 33 has been prepared by thermolysis as shown in Scheme 1 for early transition metals [25]. However, this procedure is not applicable to nickel, platinum and palladium complexes because they undergo reductive elimination, rather than beta elimination. Complexes 31 and 32 have been prepared by sodium amalgam reduction of the corresponding a-complex 37, as shown in Scheme 6 [6,7,24]. 

Solid-state thermolysis of 1 -alkyl-2,4-bipyridinium palladium complexes gave cyclometallated complexes [PdCl2(2,4 -R-bipy-H)] (R = H, Me, Bu, CsHu, CgHi, or C10H21) in quantitative yield. ... 

Dimethyl-1,2,4-triazolium iodide with palladium acetate yields the carbene adduct 182 (97JOM(530)259). Under water it undergoes cis-trans isomerization to 183. Some other derivatives were reported in 1981 (81BCSJ800). 1,1 -Methylenebis(4-alkyl-l,2,4-triazolium)diiodides (alkyl = /-Pr, n-Bu, octyl) with palladium(II) acetate give the mononuclear complexes [L Pdl ] (99EJIC1965), where L2= l,l -methylenebis(4-R-l,2,4-triazol-2-ylidene) (R = /-Pr, n-Bu, octyl). Thermolysis of the products in THF gives the rran -dinuclear complexes 184... 

In the early work on the thermolysis of metal complexes for the synthesis of metal nanoparticles, the precursor carbonyl complex of transition metals, e.g., Co2(CO)8, in organic solvent functions as a metal source of nanoparticles and thermally decomposes in the presence of various polymers to afford polymer-protected metal nanoparticles under relatively mild conditions [1-3]. Particle sizes depend on the kind of polymers, ranging from 5 to >100 nm. The particle size distribution sometimes became wide. Other cobalt, iron [4], nickel [5], rhodium, iridium, rutheniuim, osmium, palladium, and platinum nanoparticles stabilized by polymers have been prepared by similar thermolysis procedures. Besides carbonyl complexes, palladium acetate, palladium acetylacetonate, and platinum acetylac-etonate were also used as a precursor complex in organic solvents like methyl-wo-butylketone [6-9]. These results proposed facile preparative method of metal nanoparticles. However, it may be considered that the size-regulated preparation of metal nanoparticles by thermolysis procedure should be conducted under the limited condition. 

The solvent-free controlled thermolysis of metal complexes in the absence or presence of amines is the simple one-pot synthesis of the metal nanoparticles such as gold, silver, platinum, and palladium nanoparticles and Au-Ag, Au-Pt, and Ag-Pd alloy nanoparticles. In spite of no use of solvent, stabilizer, and reducing agent, the nanoparticles produced by this method can be well size regulated. The controlled thermolysis in the presence of amines achieved to produce narrow size dispersed small metal nanoparticles under milder condition. This synthetic method may be highly promising as a facile new route to prepare size-regulated metal nanoparticles. Finally, solvent-free controlled thermolysis is widely applicable to other metal nanoparticles such as copper and nickel... 

Certain transition-metal salts were also found to catalyze the apparent 1,6-ECRC. For example, thermolysis of silyl ether 74 (R1 = R2 = H) in toluene solution at 110°C (7 d) affords only a modest yield of enone 76. Attempts to cyclize the potassium enolate corresponding to 74 were also unsuccessful. However, treatment of 74 with substoichiometric amounts of a palladium(II) complex, bis(trifurany]phosphane)palladium dichloride [Pd(PFu3)2Cl ], in toluene (110 °C, 72 h) affords enone 76 in 84% yield. Substitution at R1 is detrimental, but butyl and phenyl substituents at R2 afford -substituted 76 in comparable yields. (Triphenylphos-phane)ruthenium dichloride [Ru(PPh3)Cl2] can be used in place of the palladium salt. 

PTFE increases the decomposition temperature of cadmium oxalate trihy-drate. Moreover, the products of cadmium complex degradation, in turn, increase the temperature at which an intensive degradation of PTFE begins. The thermal decomposition of the highly dispersed copper formate leads to the formation of a metal-polymer composition (20-34% Cu). The maximum on the nanoparticles granulometric composition curve corresponds to 4nm. No chemical interaction between the components was observed. The decomposition of a fine dispersion of palladium hydroxide in polyvinyl chloride (PVC) results in spatial structures with highly dispersed Pd particles (S = 26 m g ) in the nodes. This process increases in the temperature required for complete dehydrochlorination of PVC. The thermolysis of cobalt acetate in the presence of PS, PAA, and poly(methyl vinyl ketone) proceeds... 

A number of synthetic approaches involve the cleavage of a sulfur-element bond in order to generate the dithiocarbamate. Faraglia and co-workers (206, 207) developed a route to certain palladium and platinum dithiocarbamate from the thermolysis of dithiocarbamic ester complexes, upon loss of methyl halide (Eq. 27). 

It has been shown that coordinated trialkylphosphites in platinum(II), palladium(ll), and rhodium(IIl) complexes are readily hydrolyzed to form P(0)(0R)2 anions, without cleavage of the metal-phosphorus bond. The corresponding alcohols were obtained as the byproducts from these reactions. The intramolecular transformation of alkylphosphites to the corresponding phosphonates also has been described.83.84 por example, it has been shown83 that thermolysis of [Ru P(OMe)3)5] at 120 °C in hexane in a sealed tube for 24 h results in quantitative transfer of a methyl group from the alkylphosphite to ruthenium, Eq. 11.12 ... 

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