Metal method

Using flaw visuahzation system data the strength and fracture mechanics estimations are carried out in accordance with defect assessment regulatory procedure M-02-91 [5]. Recently, the additions had been included in the procedure, concerning interpretation of expert flaw visualization sysf em data, computer modelling, residual stresses, in-site properties of metal, methods of fracture analysis. 

Tbe multiple metals method is also currently published as Draft EPA Method 29 for inclusion in 40 CFR 60. f Full citation is Test Methods for T valuating Solid Waste Vhysical/Chemical Methods, SW-846, 3d ed., July 1992. 

Practice for making and using U-bend stress corrosion test specimens Recommended practice for laboratory immersion corrosion testing of metals Method for vibratory cavitation erosion test Practice for recording data from atmospheric corrosion tests of metallic-coated steel specimens... 

Metallation of alkenes with rc-BuLi-KOC(CH3)3 provides a route that is stereoselective for Z-allylic silanes.68 (See p. 632 for discussion of this metallation method.)... 

Electroless deposition as we know it today has had many applications, e.g., in corrosion prevention [5-8], and electronics [9]. Although it yields a limited number of metals and alloys compared to electrodeposition, materials with unique properties, such as Ni-P (corrosion resistance) and Co-P (magnetic properties), are readily obtained by electroless deposition. It is in principle easier to obtain coatings of uniform thickness and composition using the electroless process, since one does not have the current density uniformity problem of electrodeposition. However, as we shall see, the practitioner of electroless deposition needs to be aware of the actions of solution additives and dissolved O2 gas on deposition kinetics, which affect deposit thickness and composition uniformity. Nevertheless, electroless deposition is experiencing increased interest in microelectronics, in part due to the need to replace expensive vacuum metallization methods with less expensive and selective deposition methods. The need to find creative deposition methods in the emerging field of nanofabrication is generating much interest in electroless deposition, at the present time more so as a useful process however, than as a subject of serious research. 

Steglich s group coupled A-methyl bromoindolylmaleimide 36 with 5-tributylstannyl-l-methyl-1//-imidazole to afford 37 and then converted 37 to didemnimide C (38), an alkaloid isolated from the Caribbean ascidian Didemnum conchyliatum [25]. 5-Tributylstannyl- 1-methyl-IH-imidazole, in turn, was prepared according to Undheim s direct metalation method from 1-methyl- l/Z-imidazole [26]. 

Methods of Introducing Metal. Methods of introducing metal include chroming and dyeing together, afterchroming, and metal introduced into the dyestuff molecule in manufacture. 

The alcoholysis of oxides or hydroxides of alkaline or alkaline earth metals (method 3) is used mainly in the industrial preparation of the alkoxides [1644, 1499]. This method has become the major route to the hydrolysis-insensitive phenoxides, even in laboratory practice. The alcohols, benzene, and water have been used as reaction medias. 

Recently, the anodic oxidation of metals (method 2) was also applied for the preparation of the niobium and tantalum derivatives of M(OR)5 series (R= Me, Et, Pr, Bu ) [1478, 1616, 1639]. It should be mentioned that a crystalline oxoisopropoxideTa20(OPri)g,iPrOH (Fig. 4.1 c), was isolated from the PrOH-based electrolyte. It is destroyed on heating in vacuo, yielding Ta(OPri)J. 

The strategies used to synthesize metal complexes with the cyclopentadienyl ligands portrayed in Scheme 13 are briefly described below. The most widely used procedure begins with the corresponding cyclopentadiene derivative, which can be transformed into a cyclopentadienyl metal complex by a variety of metallation methods as described in... 

Metal alkyl or alkoxy radicals in which the unpaired electron is localized on carbon, a or /3 to the metal, are known for Li, Mg, B, Al, Si, Ge, Sn, Pb, and As (for a selection, see Table II) but not at present for a transition metal. Methods of generating such species are by y-irradiation of the solid at low temperature or by hydrogen abstraction, for example by Ph2C—6 or Bu O radicals, or the addition of a metal-centered radical (e.g., by photolysis of the metal hydride with Buj02) to an unsaturated substrate ... 

The increasing application of direct metallation methods and the importance of primary amines as synthetic intermediates have created a need for new aminating reagents. In particular, reagents that could directly transfer an N-protected group rather than a free amino group. In this context several N.O-diprotected hydroxyl-amines have been recently reported (Scheme 2) terr-butyl and allyl iV-[(arylsul-fonyl)oxy]carbamate 6 [5] and the Af,0-bis(trimethylsilyl)hydroxylamine 7 [6]. 

Of these four methods, only (i) has been seriously explored for organic metals methods (ii), (iii), and (iv) do not necessarily stabilize the dication/ dianion states. 

Metal Method Temp. Medium log of equilibrium constant Ref. 

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