Cross Experimental Procedure

In particular we thought it would be useful to include cross-references of functional group transformations and an experimental procedure, so that the reader will be able to evaluate the reaction conditions at a glance for instance is this reaction carried out at room temperature or at 200 C For 1 h or 5 days Are special catalysts required How is the reaction worked up, what yield can be expected ... 

For a while till now, our research group has been involved in studies of the properties of limit flames. Most of the results reported in this chapter were obtained for propane flames, under normal atmospheric conditions, in 300 mm long channels, with a square cross-section. The experimental procedure was described previously [25]. A flame propagating through a stationary mixture in a quenching tube or quenching channel can be characterized by the parameters defined in Figure 6.1.1. 

Two conditions must be met if this conclusion is to be revealed by the analysis. First, appropriate experimental procedures must be adopted to assure establishment of elastic equilibrium. Second, the contribution to the stress from restrictions on fluctuations in real networks must be properly taken into account, with due regard for the variation of this contribution with deformation and with degree of cross-linking. Otherwise, the analysis of experimental data may yield results that are quite misleading. 

Experimental Procedure 3.2.9. Cross Metathesis with a Molybdenum Catalyst in Homogeneous Phase (E)- -Phenyl-1-octene [929]... 

Apart from the tandem metathesis/carbonyl o[efination reaction mediated by the Tebbe reagent (Section 3.2.4.2), few examples of the use of stoichiometric amounts of Schrock-type carbene complexes have been reported. A stoichiometric variant of cross metathesis has been described by Takeda in 1998 [634]. Titanium carbene complexes, generated in situ from dithioacetals, Cp2TiCl2, magnesium, and triethylphosphite (see Experimental Procedures 3.2.2 and 3.2.6), were found to undergo stoichiometric cross-metathesis reactions with allylsilanes [634]. The scope of this reaction remains to be explored. 

The data shown in Figure 7.15 were obtained from two-ply T300/P1700 unidirectional specimens that were compression molded in a 76.2 mm (3 in.) square steel mold. The cross-sections of the consolidated specimens were examined by optical microscopy and the degree of intimate contact was determined as the amount of the interply region that was in contact divided by the total area of the cross-section. Additional details of the experimental procedures are given in Reference 22. 

Several viscosity and kinetic models, and experimental procedures for developing these models, are available for a number of commercially available resin systems [1-5]. These models allow insight into autoclave process decisions based on changes in resin viscosity and kinetic behavior and can be used to determine hold temperatures and durations that allow sufficient resin flow and cross-linking to avoid over bleeding, exotherms, and void formation. 

Experimental Procedure 4.I. Lithiatien ot brnminated, cross-linked polyshrenc... 

Polystyrene-bound allylic or benzylic alcohols react smoothly with hydrogen chloride or hydrogen bromide to yield the corresponding halides. The more stable the intermediate carbocation, the more easily the solvolysis will proceed. Alternatively, thionyl chloride can be used to convert benzyl alcohols into chlorides [7,25,26]. A milder alternative for preparing bromides or iodides, which is also suitable for non-benzylic alcohols, is the treatment of alcohols with phosphines and halogens or the preformed adducts thereof (Table 6.2, Experimental Procedure 6.1 [27-31]). Benzhy-dryl and trityl alcohols bound to cross-linked or non-cross-linked polystyrene are particularly prone to solvolysis, and can be converted into the corresponding chlorides by treatment with acetyl chloride in toluene or similar solvents (Table 6.2 [32-35]). 

Cross-linked polystyrene can be directly brominated in carbon tetrachloride using bromine in the presence of Lewis acids (Experimental Procedure 6.2 [55-58]). Thal-lium(III) acetate is a particularly suitable catalyst for this reaction [59]. Harsher bro-mination conditions should be avoided, because these can lead to decomposition of the polymer. Considering that isopropylbenzene is dealkylated when treated with bromine to yield hexabromobenzene [60], the expected products of the extensive bromi-nation of cross-linked polystyrene would be soluble poly(vinyl bromide) and hexabromobenzene. In fact, if the bromination of cross-linked polystyrene is attempted using bromine in acetic acid, the polymer dissolves and apparently depolymerizes [61]. 

Experimental Procedure 2 limminalion of cross-linked polystyrene [61]... 

As in the case of Boc protection, the Fmoc group is not usually introduced on solid phase, but rather in solution, by the use of an activated Fmoc derivative (e.g. the chloroformate Fmoc-Cl or O-Fmoc-.V-hydroxysuccinimide, Fmoc-OSu) and aqueous base (Experimental Procedure 10.3)., V-/ lkylamino acids bound to cross-linked polystyrene have been Fmoc-protected by treatment with Fmoc-Cl (4 equiv.) and DIPEA (6 equiv.) in DCM for 2 h [132,259], Primary amines on insoluble supports can also be converted into Fmoc derivatives under these conditions [260]. 

A detailed description of the apparatus shown in Figure 1 and the experimental procedure will be given elsewhere. Here, it suffices to summarize as follows. The experiments were carried out in a thermo-stated reaction cell constructed of a rectangular Pyrex tube, 4 cm x 8 cm in cross section and 38 cm in length, and placed with its... 

Fig. 7.8 also shows the results of a classical calculation and a quantum calculation that both confirm the prediction of the giant resonance based on the simple overlap criterion discussed above. The crosses in Fig. 7.8 are the results of classical Monte Carlo calculations. They were performed by choosing 200 different initial conditions in the classical phase space at Iq = 57. The ionization probabihty in this case was defined as the excitation probability of actions beyond the cut-off action Ic = 86. This definition is motivated by experiments that, due to stray fields and the particular experimental procedures, cannot distinguish between excitation above Ic > 86 and true ionization, i.e. excitation to the field-free hydrogen continuum. The crosses in Fig. 7.8 are close to the full line and thus confirm the model prediction. The open squares are the results of quantum calculations within the one-dimensional SSE model. The computations were performed in the simplest way, i.e. no continuum was... 

It is highly profitable to use various experimental techniques simultaneously, either because of their individual limitations or because of the cross-checking procedures allowed. 

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