Polymers containing organometallic units

There are a few reports dealing with the coordination polymerisation of acetone in the presence of organometallic catalysts. Such a situation results from long-term instability of acetone polymers [283]. The polymerisation of acetone with metal alkyls such as triethylaluminium as catalysts has been reported [284,285] to produce polymers containing acetalic units (Table 9.3), which was confirmed by IR spectroscopy. 

Chujo and co-workers made conjugated organometallic polymers containing platinum and tricarbonyl(arene)chromium moieties.200 (T)6-l,4-Diethynylbenzene)tricarbonylchromium reacted with /ran.v-fPBu.bPtCT in the presence of Cul produced copolymer 116 with A/w = 31,700 and PDI = 1.9. Analysis of the polymer showed 70% incorporation of chromium blocks and 30% uncoordinated phenylene units. Thermal analysis showed two... 

Fig. 27. The first oligomeric unit (123) of an organometallic polymer containing ferrocene- and [2.2]paracyclophane units (reaction paths j and k) [103,105]...

Metal-containing polymers may be produced by various methods, such as chemical reactions of precursors— in particular, reactions of metal salts in polymer solutions, the treatment of polymers with metal vapors, or the polymerization of various metal-monomer systems [1-4], Depending on the metal nature and the polymer structure, these processes lead to organometallic units incorporated into polymer chains, metal-polymer complexes, or metal clusters and nanoparticles physically connected with polymer matrix. Of special interest are syntheses with the use of metal vapors. In this case, metal atoms or clusters are not protected by complexones or solvate envelopes and consequently have specific high reactivity. It should be noted that the apparatus and principles of metal vapor synthesis techniques are closely related to many industrial processes with participation of atomic and molecular species [5]—for example, manufacturing devices for microelectronic from different metals and metal containing precursors [6]. Vapor synthesis methods employ varying metals and... 

The synthesis of polymers containing main-chain cobaltocenium units has also been studied as this 18-electron organometallic moiety is isoelectronic with ferrocene. The synthesis of partially soluble polyesters (4.6, E = 0, R=(CH2)4, CH2C6H4CH2) was reported using solution condensation polymerization techniques, and the soluble fractions were of low molecular weight (M 2500-4000,... 

Altmann, M., et al. 1995. Synthesis of novel polymers containing cyclobutadiene, thiophene and alkyne units—polymeric organometallic mesogens. Adv Mater 1 72(>. 

The thermal reaction of cis or trans 1,4-poly(butadiene) with iron carbonyls results in geometrical isomerization of the alkenyl moieties and formation of polymers containing conjugated diene) iron tricarbonyl units. In the course of our continuing studies of the formation of stable colloidal iron dispersions by thermal decomposition of metal carbonyls in the presence of functional polymers, some aspects of this work have been repeated. Our objective was to isolate the soluble organometallic polymer which was intermediate to particle nucleation and independently examine the intramolecular condensation of metal atoms to yield metal clusters and metal particles. In this paper, the structure of the intermediate obtained on thermolysis of an excess of FeCCO) in a dilute xylene solution of c/5-poly(butadiene) has been described. 

As mentioned earlier, polymers of formaldehyde are described in the next section. Polymers of higher aliphatic aldehydes and ketones have been extensively investigated but, in general, they do not have the stability necessary for commercial development. For example, acetaldehyde may be polymerized using organometallic initiators at low temperatures, e.g., triethylaluminium at —78 C in this case crystalline isotactic polymer is obtained. Also, the polymerization of acetaldehyde may be effected with cationic initiators at low temperatures (e.g., aluminium chloride at —65°C) or with metal oxides at low temperatures (e.g., alumina at —70°C) in these cases amorphous atactic polymer is obtained. The tacticity of polyacetaldehyde arises because the polymer comprises structural units which contain an asymmetric carbon atom ... 

Accordingly, this chapter deals the synthesis and the reactions of polymers containing reactive organometallics such as cobaltacyclopentadiene and titana-cyclopentadiene units in the mainchain. That is, cobaltacyclopentadiene-containing polymers have been prepared by the metallacyclization process of a low-valent cobalt... 

This polymerization strategy is quite general, and a number of organometallic polymers have been made from monomers containing functionalized Cp ligands (6-73). However, no similarly constructed polymers containing metal-metal bonded units had been reported prior to our work. 

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