Applications in Addition to Solid-state Syntheses

It is well known, that acetyl salicylic acid (Aspirin ) 67 hydrolyses by the inevitable water content upon storage and that the liberated acetic add (gas phase) catalyzes the gas-solid reaction. The crystal packing in Fig. 2.1.52 indicates double layers with ideal cleavage plane in between. 

The crystal structure of 69 is 3D-interlocked leaving only rectangular channels that appear too narrow (Fig. 2.1.54) to enable molecular migrations and thus no solid-state reactivity is to be expected for this drug either. While these judgments 

The antiarthritic drug naproxen (S-70) has a fully interlocked structure, but it exhibits prominent irregular channels to both sides of an infinite linear hydrogen bond array of the carboxylic groups (Fig. 2.1.55). This should make it sensitive to exposure to proper atmospheric pollutants. Indeed, crystalline 70 reacts with gaseous ammonia, methylamine, or diluted bromine without melting [70], 

Ibuprofen (R/S-71) is one of the most used antirheumatic drugs. Its crystal structure exhibits hydrogen bond connected double layers with a nonpolar smooth zigzag 

Three polymorphs of the most prominent antirheumatic drug diclofenac 73 have been described at room temperature. If these are long-term stable or metastable at 

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