The Cambridge Structural Database (CSD) contains a complete record of all published organic and metal–organic small-molecule crystal structures. The database has been in operation for over 50 years and continues to be the primary means of sharing structural chemistry data and knowledge across disciplines. As well as structures that are made public to support scientific articles, it includes many structures published directly as CSD Communications. All structures are processed both computationally and by expert structural chemistry editors prior to entering the database. A key component of this processing is the reliable association of the chemical identity of the structure studied with the experimental data. This important step helps ensure that data is widely discoverable and readily reusable. Content is further enriched through selective inclusion of additional experimental data. Entries are available to anyone through free CSD community web services. Linking services developed and maintained by the CCDC, combined with the use of standard identifiers, facilitate discovery from other resources. Data can also be accessed through CCDC and third party software applications and through an application programming interface.

https://journals.iucr.org/b/issues/2016/02/00/bm5086/bm5086.pdf

The Cambridge Structural Database

From molecules to crystal engineering: supramolecular isomerism and polymorphism in network solids.

There is a special reason for reviewing this book at this time: it is the 50th edition of a compendium that is known and used frequently in most chemical and physical laboratories in many parts of the world. Surely, a publication that has been published for 56 years, withstanding the vagaries of science in this century, must have had something to offer. There is another reason: while the book is a standard fixture in most chemical and physical laboratories, including those in medical centers, it is not as frequently seen in the laboratories of physician's offices (those either in solo or group practice). I believe that the Handbook can be useful in those laboratories. One of the reasons, among others, is that the various basic items of information it offers may be helpful in new tests, either physical or chemical, which are continuously being published. The basic information may relate

Handbook of Chemistry and Physics

The aim of this critical review is to provide a broad but digestible overview of mechanochemical synthesis, i.e. reactions conducted by grinding solid reactants together with no or minimal solvent. Although mechanochemistry has historically been a sideline approach to synthesis it may soon move into the mainstream because it is increasingly apparent that it can be practical, and even advantageous, and because of the opportunities it provides for developing more sustainable methods. Concentrating on recent advances, this article covers industrial aspects, inorganic materials, organic synthesis, cocrystallisation, pharmaceutical aspects, metal complexes (including metal–organic frameworks), supramolecular aspects and characterization methods. The historical development, mechanistic aspects, limitations and opportunities are also discussed (314 references).

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Mechanochemistry: opportunities for new and cleaner synthesis

The program Mercury, developed at the Cambridge Crystallographic Data Centre, was originally designed primarily as a crystal structure visualization tool. Over the years the fields and scientific communities of chemical crystallography and crystal engineering have developed to require more advanced structural analysis software. Mercury has evolved alongside these scientific communities and is now a powerful analysis, design and prediction platform which goes a lot further than simple structure visualization.

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Mercury 4.0: from visualization to analysis, design and prediction

The outcome of synthetic procedures for crystalline organic materials strongly depends on the first steps along the molecular self-assembly pathway, a process we know as crystal nucleation. New experimental techniques and computational methodologies have spurred significant interest in understanding the detailed molecular mechanisms by which nuclei form and develop into macroscopic crystals. Although classical nucleation theory (CNT) has served well in describing the kinetics of the processes involved, new proposed nucleation mechanisms are additionally concerned with the evolution of structure and the competing nature of crystallization in polymorphic systems. In this Review, we explore the extent to which CNT and nucleation rate measurements can yield molecular-scale information on this process and summarize current knowledge relating to molecular self-assembly in nucleating systems.

Nucleation of Organic Crystals—A Molecular Perspective

A number of mineralogical and synthetic precipitates undergo solid to solid phase changes via a solution phase. A review of the literature reveals a lack of both experimental data and a framework for its interpretation. A model is developed, for the case of a polymorphic phase transformation, which involves the dissolution of the metastable phase and growth of nuclei of the stable phase. The concepts of dissolution and growth time scales have been introduced and it is shown that their sum is the time required for the disappearance of the metastable phase. Mechanistic insight is best obtained by measure­ment of the supersaturation profile rather than conversion data. It is shown that such profiles are dominated by the plateau supersaturation, which is the point at which dissolution and growth are balanced. Its value is determined by the relative surface areas of the phases and their kinetic constants. The model has been successfully used to simulate available kinetic data for the α → β polymorphic transformation in copper phthalocyanine.

/pdf/the-kinetics-of-solvent-mediated-phase-transformations-15rqtsex3i.pdf

The kinetics of solvent-mediated phase transformations

A combined modeling and experimental strategy has been applied to the problem of stabilisation of a metastable conformational polymorph. For the first time additives have been successfully selected which by virtue of their conformation are able to selectively inhibit the appearance of the stable I² polymorph of L-glutamic acid and hence stabilize the metastable I± structure.

Polymorphism in Molecular Crystals: Stabilization of a Metastable Form by Conformational Mimicry

Nucleation of Organic Crystals - A Molecular Perspective

We describe the use of ternary, isothermal phase diagrams of co-crystal-forming systems as a basis for understanding current crystallization methodologies and for experimental design in the preparation of co-crystals.

Roger J. Davey

Papers

Nucleation of Organic Crystals—A Molecular Perspective

The kinetics of solvent-mediated phase transformations

Polymorphism in Molecular Crystals: Stabilization of a Metastable Form by Conformational Mimicry

Nucleation of Organic Crystals - A Molecular Perspective

Making Co-crystals-The utility of ternary phase diagrams