Synthons extrinsic

Some subsequent discussion on compound 3 followed our original paper on this subject (N. Masciocchi, M. Bergamo, A. Sironi, Comments on the elusive crystal structure of 4-iodo-4 -nitrobiphenyl Chem. Comm, 1998,1347-1348 J. Hulliger, P. J. Langley, On intrinsic and extrinsic defect-forming mechanisms determining the disordered structure of 4-iodo-4 -nitrobi-phenyl Chem Comm, 1998, 2557-2558), but these papers, which describe the effects of small amounts of 4,4 -dinitrobiphenyl impurity in 3, only reinforce the idea of structures based on N02—I synthons. 

The surface as a collection of unsaturated interactions due to the surface termination of the bulk crystal structure -extrinsic synthons. This will be discussed further in Section 8.3.4. 

The modem process chemist has at their disposal tools that allow a link to be made between the bulk crystal chemistry, the surface chemistry of the crystal faces and their potential interactions with solvents and impurities. Examples of industrial application include aspirin [58], the agrochemical product paclobutrazol [59]. The subsequent sections in this chapter provide the details of how such an understanding of the intrinsic and extrinsic synthons can be used in the design of pharmaceutical products in particular addressing the challenges in form selection, particle fonnation and formulation design. 

Deconstructing the Supra-Molecular Interactions at Surfaces - Extrinsic Synthons... 

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