Reactions in the Solid State

Many of the above-described examples highlight the limitations of radical reactions in solution. However, the potential ofahighly exothermic and diffusion-controlled C—C 

---

Exothermic Decompositions These decompositions are nearly always irreversible. Sohds with such behavior include oxygen-containing salts and such nitrogen compounds as azides and metal styphnates. When several gaseous products are formed, reversal would require an unlikely complex of reactions. Commercial interest in such materials is more in their storage properties than as a source of desirable products, although ammonium nitrate is an important explosive. A few typical exampes will be cited to indicate the ranges of reaction conditions. They are taken from the review by Brown et al. ( Reactions in the Solid State, in Bamford and Tipper, Comprehensive Chemical Kinetics, vol. 22, Elsevier, 1980). 

Volume 19 Volume 20 Volume 21 Volume 22 Simple Processes at the Gas—Solid Interface Complex Catalytic Processes Reactions of Solids with Gases Reactions in the Solid State Additional Section... 

One of the common tests for free radical reactions seems to be violated in these experiments, namely that they should have nearly zero activation energy. Annealing reactions in the solid state are obviously temperature... 

Thermal and photochemical reactions in the solid state which were studied before 1999 are summarized in reviews [1] and books [2]. 

When a solution of 10a and 11 in ether was kept at room temperature for 12 h, a 2 1 inclusion complex of 10a and 11 was obtained as colorless prisms (m.p. 134-137 °C) in 72% yield. When a powdered mixture of the inclusion crystal and 7 was kept at room temperature in the solid state for 3 days, (+)-trans-1,2-dibromocyclohexane (12) of 12% ee was obtained in 56% yield by distillation of the reaction mixture [3]. Much more efficient enantioselective reactions in the solid state are described in Sect. 6. 

For heterogeneous reactions in the solid state, tests on small quantities with different particle size distributions can help the technician make the right decisions. 

State decarbonylation reaction in total synthesis was reported recently in the case of natnral prodnct (+)-herbetenolide, which farther illustrates the exquisite control that the solid state may exert on the chemical behavior of the otherwise highly promiscuous reactive intermediates. As word or caution, it should be mentioned that intramolecular quenching effects known to act in solution can also affect that reaction in the solid state. Recently reported examples include the well-known intramolecular P-phenyl and electron transfer quenching. ... 

Other Gas Reactions. Several other reactive gases or vapours were examined but found to be unsatisfactory. No ester formation ( 1745 cm"1) was found when oxidatized films were exposed to acetic acid or formic acid vapour. Alcohol/carboxylic acid reactions in the solid state have often been suggested as the source of ester products, but not substantiated (4,5). Gaseous ammonia reacted with carboxylic acid groups to give absorptions at 1550 cm"1 [-C(=0)-0 ] and 1300 cm"1 (NHi +). However, these absorptions were very broad and the method inferior to acid measurement by SF. Although N20 did not react with oxidized polyolefins, the reaction of N02 with oxi-... 

During a phase transition or a reaction in the solid state which results in one or more products of lower symmetry, very often the higher symmetry of the starting material is indirectly preserved by the orientation of domains formed within the crystalline matrix. 

Reactions in solids are often vastly different from those that take place in solutions. Because many of the reactions in the solid state involve inorganic materials, an introduction to this important topic is presented in this chapter to show some of the principles that are applicable to this area of inorganic chemistry. The emphasis is on showing several types of reactions, but no attempt is made to present comprehensive coverage of the hundreds of reactions that take place in the solid state. Although some 255... 

FIGURE 8.1 The variation of a versus time for a hypothetical reaction in the solid state. Curve I shows the evolution of a gas (A) followed by an induction period (B) before the maximum rate is reached, curve II represents a reaction that shows an induction period (B) before reaching maximum rate, and curve III represents a reaction that begins at the maximum rate. 

House, J. E. (1993). "Mechanistic Considerations for Anation Reactions in the Solid State." Coord. Chem. Rev. 128, 175-191. 

House, J. E. (2007). Principles of Chemical Kinetics, 2nd ed. Elsevier/Academic Press, San Diego, CA. Chapter 7 is devoted to reactions in the solid state. 

Electron donor groups (EDG) on the aromatic ring favour its displacement to the right while electron withdrawing group (EWG) favours its displacement to the left. Selenobenzophenone monomer in solution is isolated as a dimer in the solid state. Dimerization of the stable 12 to the 1,3-ditelluretane was observed in the solid state, in solution the dimer reforms 12.25 26 Contrary to the reaction in the solid state dimerization does not take place in solution. 

---