Dinuclear palladium compounds

The influence of different classes of palladium compounds was also investigated (Table 2). Pd(II)- and Pd(0)-complexes, neutral and ionic palladium species as well as mono- and dinuclear palladium compounds were applied as catalyst precursors. 

Tschierske synthesized the butterfly mesogens 132-134 (Scheme 72, Table 9). These compounds are based on a macrocyclic crown-like para-cyclophane ring containing two 2-phenylpyrimidine units. Of/to-palladation and subsequent treatment with substituted half-disks like (5-diketones gave the desired dinuclear palladium complexes with 4 (132), 8 (133), and 12 (134) peripheral alkyl chains [127]. 

Four chiral homologous complexes were also prepared. None of the palladium complexes showed mesomorphic properties, whereas a monotropic chiral discotic nematic phase was observed for the platinum complex (Table 18). The absence of mesomorphism for the dinuclear palladium complexes may be due to the type of chiral chain used, which differed from that used for the platinum system. All of the complexes form charge-transfer complexes with TNF. A Colh phase was induced for the two halo-bridged palladium complexes and for the platinum complex, as was observed for their non-chiral analogs. Flowever, the chiral nematic phase of the platinum compound was suppressed. At low TNF content, a chiral Nq phase was stabilized for the thiocyanato-bridged compound along with a non-chiral No phase at higher concentration. 

Bis(trifluorosilyl)bis(trimethylphosphine)paIladium was formed by a metal vapor/plasma technique (Scheme 1).[" Stable c -bis(silyl)palladium complexes were prepared from the direct reaction of either hydrosilanes or 1,2-dihydrodisilanes with the novel dinuclear palladium hydride (Scheme 2). A first X-ray crystal structure of the bis(silyl) compound 1 was obtained. ... 

An extension to work on platinum(i) isocyanides discussed above has been undertaken, showing that it is possible to coordinate metals other than platinum. In the first instance, platinum and palladium compounds were added to the dinuclear Pt(i) compound 103 to give either the linear trinuclear complex 105 (when a -M(0) source was used), or a combined dimer-monomer complex 124 (when a -M(ii) source was added) (Scheme 28). An A-frame complex 125 results when the -source is added to 102. 

Dinuclear palladium organyls with a discoid molecular shape constitute a class of electron donor compounds displaying an unusual and complex phase behavior with TNF as a strong electron acceptor [64] (see Fig. 7). The mesomorphism of these meso-gens, exhibiting monotropic nematic discotic phases in their pure forms, in TNF-CT... 

Heterometal alkoxide precursors, for ceramics, 12, 60-61 Heterometal chalcogenides, synthesis, 12, 62 Heterometal cubanes, as metal-organic precursor, 12, 39 Heterometallic alkenes, with platinum, 8, 639 Heterometallic alkynes, with platinum, models, 8, 650 Heterometallic clusters as heterogeneous catalyst precursors, 12, 767 in homogeneous catalysis, 12, 761 with Ni—M and Ni-C cr-bonded complexes, 8, 115 Heterometallic complexes with arene chromium carbonyls, 5, 259 bridged chromium isonitriles, 5, 274 with cyclopentadienyl hydride niobium moieties, 5, 72 with ruthenium—osmium, overview, 6, 1045—1116 with tungsten carbonyls, 5, 702 Heterometallic dimers, palladium complexes, 8, 210 Heterometallic iron-containing compounds cluster compounds, 6, 331 dinuclear compounds, 6, 319 overview, 6, 319-352... 

The ligands triphos or/ and np in presence of compounds of iron, cobalt, nickel, rhodium, iridium and palladium, by reaction with THF solutions of white phosphorus, P, or yellow arsenic, As, form mononuclear or dinuclear sandwich complexes containing the cyclo-triphosphorus or cyclo-triarsenic units which behave as 3n-electrons rings. 

Diaryl ditellurium compounds and tetrakis[triphenylphosphane]palladium reacted in benzene to form the dinuclear complex bis[/r-arenetellurolato]bis[arenetellurolato]bis[tri-phenylphosphane]dipalladium3. 

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