M , reactions

Hanggi, R, Talkner, P., Borkovec, M. Reaction-rate theory fifty years after Kramers. Revs Modern Phys. 62 (1990) 251-341. 

Section 16 11 Epoxides are much more reactive than ethers especially m reactions that lead to cleavage of their three membered nng... 

An orbital hybridization description of bonding m methylamme is shown m Figure 22 2 Nitrogen and carbon are both sp hybridized and are joined by a ct bond The unshared electron pair on nitrogen occupies an sp hybridized orbital This lone parr IS involved m reactions m which amines act as bases or nucleophiles The graphic that opened this chapter is an electrostatic potential map that clearly shows the concentration of electron density at nitrogen m methylamme... 

The value of alkyl halides as starting materials for the preparation of a variety of organic functional groups has been stressed many times In our earlier discussions we noted that aryl halides are normally much less reactive than alkyl halides m reactions that involve carbon-halogen bond cleavage In the present chapter you will see that aryl halides can exhibit their own patterns of chemical reactivity and that these reac tions are novel useful and mechanistically interesting... 

Aryl halides are less reactive than alkyl halides m reactions m which C—X bond breaking is rate determining especially m nucleophilic sub stitution reactions... 

Groll, M., Reaction beds for dry sorption machines. In proceedings of Solid Sorption Refrigeration, Paris, IIR,1992, pp.207 214. 

Walas, S. M., Reaction Kinetics for Chemical Engineers, MeGraw-Hill, New York, 1959. 

The kinetics of alkaline hydrolysis of phenyl cinnamate were studied at 25°C, in solutions containing 0.8% acetonitrile ionic strength, 0.3 M initial ester, 8.19 X 10- M reaction followed spectrophotometrically in 5-cm cells at 295 nm. For studies at three pH values, these absorbance data were obtained. The pH was established with sodium hydroxide of the normality specified in the heading of the table (as titrimetrically determined). 

The incompleteness of the other data precludes generalization. However, a few apparent inconsistencies may be indicated to stimulate further research. Insertion of another aza group into 2-chloroquinoline causes the reactivity sequence o >m (reaction with piperidine) or, even, o reaction with CgHsO"), involving only relatively small factors and, in any case, in sharp contrast with the above-mentioned effects on 2-chloropyridine as a substrate. Further, meta-aza activation in all cases involving the ethoxide ion is fairly strong suggest-... 

Arenes, on complexdQon with Cr, Fe, Mn, and so forth, acquire strongly electrophilic character, such complexes m reactions with nucleophiles behave as electrophilic tutroarenes. Synthesis of aromatic tutnles via the temporary complexanon of rutroarenes to the catiotuc cyclopentadienyhron moiety, cyarude addition, and oxidative demetalation v/ith DDQ has been reported fEq. 9.43 ... 

Reaktions-baim, /. path of a reaction, -bereit-schaft, /. readiness to react, reactivity, -druck, m. reaction pressure. 

Reaktions-tragheit, /. slowness in reaction, -turm, m. reaction tower, -verh tnis, n. reaction proportion or ratio, -verlauf, m. course of a reaction, -verauch, m. reaction test, -wirme, /. heat of reaction, -zeit, /. reaction time. 

---