Other Inserts

Where it is required to use metal or other inserts for fastening of upholstery elements or coverings. 

Another consideration is the ability of a material to provide a surface that is compatible with the requirements of the application a smooth finish for extruded profiles, molded-in colors, textured surfaces, etc. The compatibility of the major processes with in-mold coating and other insert-surfacing materials, and their compatibility with surface decoration secondary processes, could also be important. 

Inserts are any parts of any material located into another plastic part during or after its processing. The best known are metal inserts for assembly by screwing but there are numerous other insert types (plastic parts, films. ..) for numerous other applications. 

Other insertions may involve isonitriles, alkynes, alkadienes, CO2, and SO2. They will not be dealt with here. 

Metal complexes of heterocyclic compounds display reactivities changed greatly from those of the uncomplexed parent systems. All of the -electron system(s) of the parent heterocycle can be tied up in the complex formation, or part can be left to take part in alkenic reactions. The system may be greatly stabilized in the complex, so that reactions, on a heteroatom, for example, can be performed which the parent compound itself would not survive. Orbital energy levels may be split and symmetries changed, allowing hitherto forbidden reactions to occur. In short, a multitude of new reaction modes can be made possible by using complexes dimerization of azirines with a palladium catalyst serves as a typical example (Scheme 81). A variety of other insertion reactions, dimerizations, intramolecular cyclizations, and intermolecular addition reactions of azirines are promoted by transition metals. 

In addition to serving as ligands, organostannylenes can also insert into metal-ligand bonds (cf. Fig. 10). In the reaction shown in Eq. (50) (78), two moles of the divalent tin compound react, one forming a terminal stannylene complex, and the other inserting into the Pt—Cl bond. 

This is the second chapter of a two-part review concerned with insertion reactions of transition metal-carbon a-bonded compounds. The first chapter, which appeared in Volume 11 of this series (137), provided a broad introduction to the subject of insertion reactions in general and a detailed treatment of the carbon monoxide insertion and decarbonylation. Presented herein are the insertion and elimination reactions of sulfur dioxide and of a few other unsaturated molecules. The reactions of sulfur dioxide are accorded a complete literature coverage, whereas those of the other inserting species are treated selectively. Metal-carbon a-bonded compounds of the main group elements are discussed only in the context of comparisons with their transition metal analogs. 

The CO insertion reaction into the metal hydride bond is in fact a member of the class of ligand insertion reactions to which much theoretical work has been devoted (28,29-35). Some years ago we analyzed the ethylene insertion into the rhodium hydride bond of a Rh(III) hexacoordinated complex (. We later focused our attention on the CO insertion reaction into the Mn-H bond ofHMn(CO)5 (37-39) and very recently we have undertaken the study of the CO2 insertion reaction into the Cr-H bond of HCr(CO)5 (C. Bo and A. Dedieu, Inorg. Chem., in press). We will concentrate here on the CO insertion reaction and compare it to the two other insertion reactions. The study of the reaction (1) was carried out at both the SCF and... 

This section considers only the direct insertion reactions represented by equation (a), although many other insertion-type products can be prepared by other routes. For example CpFe(CO)2SnCl2CO(CO)4 (Cp = cyclopentadienyl) can be prepared by the reaction of CpFe(CO)2SnCl3 with Co2(CO)s, but not by the direct insertion of SnCl2 into the Fe-Co bond of CpFe(CO)2Co(CO)4. ... 

Insertion Reactions into Metal-Metal Bonds 11.7.5. Other Insertion Reactions... 

After oxidative addition of an unsymmetrical cr bond (E-H) to the metal, an unsaturated compound can insert into either the M-E or the M-H bond. In some cases, such as the hydrosilylation of carbonyl compounds, the 7r bond of the substrate inserts into the M-E bond, whereas, in others, insertion of the ir bond of the substrate into the M-H bond occurs faster. In any case, either pathway gives the same product after reductive elimination. 

Particularly if pellets with high density or strength and small diameter must be produced, the necessary die thickness and effective hole length may be rather incompatible. In such cases replaceable insert plates with short bores may be used (Figure 328(a)). Other inserts may be used as replacements in the case of wear and to salvage the overall die body (Figure 328(b) ) or to fulfill process requirements, such as cooling of the dies. ... 

OTHER INSERTION METERS. Modified forms of magnetic meters, turbine meters, ultrasonic meters, thermal mass flowmeters, and other types are available as insertion meters. They all have advantages for certain services. Insertion meters are generally cheaper than full-bore meters and are usually the most cost-effective method of measuring flow in large pipes. 

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