Toluene, coordination

Toluene remained for longer periods of time in the lipid-rich white matter of the brain. The white matter of the brain contains axonal fibers only and no cell bodies. Some axons are myelinated, with a sheath of lipids that appears white, to speed transmission. Because toluene has a high uptake and low clearance from the white matter, this is an area that can suffer toxic damage from inhalant abuse. Damage and shrinkage of the white matter has been demonstrated in inhalant abusers. Inhalants were also found in the cerebellum, an area of the brain that is involved in motor coordination. Toluene is known to cause many malfunctions in behavior controlled by the cerebellum, resulting in an unsteady walk, muscle incoordination, and dizziness. 

The coordination of toluene to form TpRe(CO)(MeIm)(// -toluene) results in a mixture of four regio- and stereoisomers.The addition of HOTf and MMTP to TpRe(CO)(MeIm)(f/ -toluene) results in a tandem addition to the coordinated toluene to produce c/y-3-dimethylcarbomethoxymethyl-6H-hydro-l,4-cyclohexa-diene in 62% isolated yield. Despite the mixture of Re isomers in the parent solution, this is the only organic product isolated from the reaction. Likely due to the additional steric bulk of the methyl group, Michael acceptors or acetals were not incorporated at C3. 

Figure 7, Coordination polyhedron in Pb50(SRr)s showing two loosely coordinated toluene molecules (Rp substituents omitted for clarity disorder at sulfur atom S8).

Cycloaddition of COj with the dimethyl-substituted methylenecyclopropane 75 proceeds smoothly above 100 °C under pressure, yielding the five-membered ring lactone 76. The regiocheraistry of this reaction is different from that of above-mentioned diphenyl-substituted methylenecyclopropanes 66 and 67[61], This allylic lactone 76 is another source of trimethylenemethane when it is treated with Pd(0) catalyst coordinated by dppe in refluxing toluene to generate 77, and its reaction with aldehydes or ketones affords the 3-methylenetetrahy-drofuran derivative 78 as expected for this intermediate. Also, the lactone 76 reacts with a, /3-unsaturated carbonyl compounds. The reaction of coumarin (79) with 76 to give the chroman-2-one derivative 80 is an example[62]. 

Draw a plot in polar coordinates of the scattering envelope in the xy plane. How would the envelope of a Rayleigh scatterer compare with this plot By interpolation, evaluate 145, iiss, and z. Use Fig. 10.13 to estimate the value of rrms to which this dissymmetry ratio corresponds if X (in toluene) is 364 nm. What are some practical and theoretical objections to this procedure for estimating rrms ... 

Epichlorohydrin Elastomers without AGE. Polymerization on a commercial scale is done as either a solution or slurry process at 40—130°C in an aromatic, ahphatic, or ether solvent. Typical solvents are toluene, benzene, heptane, and diethyl ether. Trialkylaluniinum-water and triaLkylaluminum—water—acetylacetone catalysts are employed. A cationic, coordination mechanism is proposed for chain propagation. The product is isolated by steam coagulation. Polymerization is done as a continuous process in which the solvent, catalyst, and monomer are fed to a back-mixed reactor. Pinal product composition of ECH—EO is determined by careful control of the unreacted, or background, monomer in the reactor. In the manufacture of copolymers, the relative reactivity ratios must be considered. The reactivity ratio of EO to ECH has been estimated to be approximately 7 (35—37). 

Solvents acetone, methyl ethyl ketone (MEK), toluene, xylene, glycol, ethers, alcohol defats and dries skin some may be absorbed may carry other components through skin high volatility, exposure possible irritation central nervous system depression (e.g. dizziness, loss of coordination) low to high toxicity, longterm effects... 

The crucial experiment suggesting that the H2 molecule might act as a dihapto ligand to transition metals was the dramatic observation that toluene solutions of the deep purple coordinatively unsaturated 16-electron complexes [Mo(CO)3(PCy3)2] and [W(CO)3-(PCy3)2l (where Cy = cyclohexyl) react readily and cleanly with Ha (I atm) at low temperatures to precipitate yellow crystals of [M(CO)3H2(PCy3)2] in 85-95% yield. The... 

A recent addition to the many examples of octahedral coordination of O (Table 14.3) is the unusual volatile, hydrocarbon-soluble, crystalline oxo-alkoxide of barium [H4Ba6(/i(i-0)(0CH2-CH2,OMe)i4l, which forms rapidly when Ba granules are reacted with Me0CH2CH20H in toluene suspension. ... 

THF. Non-coordinating solvents sucli as toluene or mixed toluene/cliloroalkane solvent systems afford tlie higliest tt values. 

The observation of Tsuji et al. 148) concerned with copolymerization of 1- or 2-phenyl butadiene with styrene or butadiene illustrates again the importance of the distinction between the classic, direct monomer addition to the carbanion, and the addition involving coordination with Li4. The living polymer of 1- or 2-phenyl butadiene initiated by sec-butyl lithium forms a block polymer on subsequent addition of styrene or butadiene provided that the reaction proceeds in toluene. However, these block polymers are not formed when the reaction takes place in THF. The relatively unreactive anions derived from phenyl butadienes do not add styrene or butadiene, while the addition eventually takes place in hydrocarbons on coordination of the monomers with Li4. The addition through the coordination route is more facile than the classic one. 

The complexes are formed with 68% (R = t-Bu) and 73% [R = Me2Si(t-Bu)N] yield in warm (85°C) toluene in the course of 90 min. Surprisingly, the B—N distance is extended only a little ( 0.03 A), compared with the free iminoborane. In contrast to this side-on coordinated iminoborane, the zirconium complex (rj -Cp)2ZrCl(H)... 

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