Luttinger catalysts

One of the most interesting alternatives to the Shirakawa catalyst has been the systems disclosed by Luttinger 22-23) and later elaborated by Lieser et al. 24). The tris(2-cyanoethyl)phosphine complex of nickel chloride reacts with sodium boro-hydride to produce a catalyst system capable of polymerizing acetylene in solutions in either alcohol or, quite remarkably, water. A more efficient catalyst is obtained by replacing the nickel complex with cobalt nitrate. Interest in Luttinger polyacetylene seems to have waned in the last few years. 

Given that "electromembranes" may have utility, and given that conductive polymer research has advanced considerably in recent times, it was decided to investigate synthetic methods to create electromembranes using microporous membranes as substrates for the deposition of Ziegler-Natta and Luttinger catalysts, followed by the heterogeneous polymerization of acetylene. 

The Luttinger catalyst was prepared as follows. Sodium borohydride,... 

The effect of soak time in the Luttinger catalyst was also studied. Samples were dipped quickly once, dipped quickly five times, soaked for 3 seconds, for 5 seconds, for 10 seconds and for 1 minute, then exposed to acetylene. No change in performance was observed. 

Catalyst System, the Luttinger catalyst system (11), which is a... 

Luttinger. The main advantage of this technique is that the requirement for rigorous exclusion of moisture normally associated with the Ziegler catalyst is circumvented. A new type of polyacetylene film... 

The polymerization of acetylene by using [Rh(l,5-Cod)Cl]2, where 1,5-Cod is c/j,cw-cycloocta-l,5-diene, or [Rh(NBD)Cl]2, where NBD is bicyclo[2,2,I]hepta-2,5-diene, was studied by UV-vis spectroscopy [79,80]. The growing polyacetylene chains were identified by three maxima at 500, 544, and 590 nm as a result of subtracting the spectrum of the catalyst from that of the reaction mixture. The first-order derivative of the absorption spectrum of the growing polyacetylene exhibited vibrational maxima at 480, 515, 550, and 600 nm for the cis-isomer and at 640, 670, and 710 nm for the trans-isomer. UV-vis and FTIR spectroscopies were used in the study of the structure of thin freestanding films of cis- and trans-PA obtained by using Rh(I) complexes. The absorption spectrum shows no vibrational structure, which was detected in acetylene polymerization in ethanol. The microstructure of PA is very similar to that of PA synthesized with a Luttinger catalyst in terms of sp defects in the polymer chains detected by FTIR spectroscopy. 

Terlemezyan, L. Mihailov, M. On the configuration of polyacetylene obtained by Luttinger s catalyst Makromol. Chem., Rapid Commun. 1982,3, 613-161. 

The stability, particularly the susceptibility to autooxidation, is the Achilles heel of the new materials as well as of organic polymers in general. The problem of oxidative damage has therefore been the object of intensive research. Poly(acetylene) (CH) . manufactured with Ziegler-Natta, Luttinger or other catalysts were used as model compounds. 

A suspension of poly(acetylene) was prepared carrying out the polymerization as described by either Luttinger s or Shirakawa s method under rapid stirring of the catalyst solution into which acetylene was introduced by a gas inlet. 

The data compiled in Table 4 clearly show that the surface of the sample accessible to the chemical reaction in the "doping" is one of the most important parameters. They also show that the catalyst system used (Shirakawa vs. Luttinger) and the method of preparation of the free standing film (in situ preparation vs. successive polymerization and film formation) is of little consequence as far as the level of conductivity is concerned. 

Fig. 3. Catalytic polymerization of acetylene using (a) Ziegler-Natta and (b) Luttinger catalysts, respectively.

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