Poly reaction with nickel

The family of poly(pyrazol-l-yl)borates has been widely used as supporting ligands in nickel coordination chemistry.556,557 Complex (191) is an example, where unusual cysteine coordination is achieved at a tris(pyrazolylborate)nickel(II) template.601 (191) undergoes rapid reaction with molecular oxygen to presumably form a sulfinate. 

Applications of the Marcus theory to reactions of nickel(III) species with Fe2+ and V02+ aquo ions 158) lead to values of 10 3-10-2 M l sec-1 for Fe3+/2+ and 10-103 M-1 sec-1 for VO(OH)2+/+. These rate constants are larger than for the corresponding data derived using poly (pyridine) derivatives where there may be a contribution from the n -n interaction of the ligand orbitals. 

In connection with nickel-catalysed reductive coupling reactions of dihaloarenes, leading to poly(arylene)s, the copper-catalysed reductive carbenoid coupling reactions involving substituted bis(dichloromethyl)arenes and metals or other reductants should be mentioned. The reductive carbenoid coupling of bis(phenyldichloromethyl)arene with zinc in the presence of Cu-based catalysts is shown below ... 

However, it was also clear, based on NMR studies, that the type of addition polymer formed in run 1 was quite different from that produced using, for example, [(z7 -crotyl)Ni(l,5-COD)]PF5. A comparison of the polymer ll NMR spectra is given in Fig. 4.25. Note the dissimilarity between the two spectra. The same is true of their NMR spectra. The formation of a catalyst unique and distinct from [(/7 -crotyl)Ni(l,5-COD)]PF6 by the reaction of nickel(2,2,6,6-tetramethyl-3,5-hep-tanedionate)2 or Ni(dprri), AlEts, and BlC Fsls would be consistent with the production of poly(norbornene) exhibiting different NMR spectra and apparently different microstructures. 

The reaction involves the amine-catalyzed conversion of an aldehyde into a nitroalkene by reaction with nitromethane followed by a transition-metal-catalyzed Michael addition of p-dicarbonyl compounds in the same reaction vessel. Typically, amine catalysts and nickel complexes are incompatible due to their tendency to chelate and to render each other inactive. However, microencapsulation of poly(ethyleneimine) (PEI) forms catalyst 140, which can successfully be used in tandem with the nickel-based catalyst 141 (Figure 3.6). 

This approach was first accomplished by Ziegler in his early work when nickel was introduced with titanium, either purposely or through autoclave corrosion as part of the investigation of the Aufbau reaction. The nickel dimerized ethylene to butene, while the titanium incorporated it at low levels yielding poly ethylenes with low levels of ethyl branches. We have been told that this work appears in early notebooks from the Ziegler laboratory, but we have been unable to find a reference in the open literature. 

Copolymers of di5mes 8 with phenyl isocyanate afford poly(2-pyridones) 9. This copolymerization reaction uses nickel(O) complexes as initiators (63). 

Finally, it is worth noting that Reynolds and Wang [65] have prepared conducting polymers via the reaction of nickel bromide with a tetra-anion derived from bis(4-styryldithiocarbonate) oxide. The resulting poly[bis(4-oxystyryldithiolene)nickel] is soluble in its reduced form, although it... 

Amine-terminated poly(alkylene oxide)s have been made and used in industry for over half a century. These compounds can be prepared in various ways. Lee and Winfrey (54) describe a process in which poly (propylene oxide)s are converted into diamines by reaction with anhydrous ammonia, hydrogen and anhydrous ammonia, or ammonium hydroxide in the presence of a Raney nickel catalyst. In the following... 

Greater durability of the colloidal Pd/C catalysts was also observed in this case. The catalytic activity was found to have declined much less than a conventionally manufactured Pd/C catalyst after recycling both catalysts 25 times under similar conditions. Obviously, the lipophilic (Oct)4NCl surfactant layer prevents the colloid particles from coagulating and being poisoned in the alkaline aqueous reaction medium. Shape-selective hydrocarbon oxidation catalysts have been described, where active Pt colloid particles are present exclusively in the pores of ultramicroscopic tungsten heteropoly compounds [162], Phosphine-free Suzuki and Heck reactions involving iodo-, bromo-or activated chloroatoms were performed catalytically with ammonium salt- or poly(vinylpyrroli-done)-stabilized palladium or palladium nickel colloids (Equation 3.9) [162, 163],... 

With a few exceptions, 1,2-disubstituted alkenes are not polymerized because of steric hindrance. The exceptions include 1-deuteropropene (Sec. 8-4g) and cydoalkenes. Polymers are obtained from some 1,2-disubstituted alkenes, but the reactions involve isomerization of the monomer to a 1-alkene prior to polymerization, e.g., 2-butene yields poly( 1-butene) [Endo et al., 1979]. There is one report of polymerization of trans-2-butene to poly( ranv-2-butene) using the a-diimine nickel initiators described in Sec. 8-8b [Leatherman and Brookhart,... 

By taking advantage of the simultaneous enzyme inhibition by nickel, the nickel-catalyzed ATRP, and the stereoselectivity of the enzyme, Peters et al. obtained chiral block copolymers by this method from 4-methyl-e-caprolactone (4-MeCL) by [27], The polymerization of racemic 4-MeCL showed good enantioselectivity and produced a chiral macroinitiator with ATRP endgroup by selectively polymerizing only the (5 )-4-MeCL. Macroinitiation was then started by adding the nickel catalyst and methyl methacrylate (MMA) to the reaction mixture, which simultaneously inhibited the enzyme and activated the ATRP process. Chiral poly[MMA-fe-(5 )-4-MeCL] was successfully obtained in this synthesis. 

A 500-ml reaction flask was charged with the step 1 product (43.1 mmol), the poly condensate of 4,4 -dichlorobenzophenone-2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexa-fluoropropane (Mn 11,200 Da 1.80 mmol), bis(triphenylphosphine) nickel dichloride (1.35 mmol), sodium iodide (5.85 mmol), triphenylphosphine (18 mmol), and zinc (108 mmol). The mixture was dried under vacuum and then treated with 87 ml of N,N-dimethylacetamide and kept in the temperature range of 70-90°C. After 3 hours the mixture was diluted with 200 ml of V,V-dimethylacetamide and insoluble components removed by filtration. The filtrate was then added to 1.5 liters of methanol containing 10 vol% concentrated hydrochloric acid to precipitate the polymer. After collecting, the precipitate was dried to obtain 28.5 g of product having polyhydroxyl groups. 

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