1,721,267 research outputs found
Diffraction at the nanoscale. Nanocrystals, defective & amorphous materials
No full textThree years after the publication of the book “Analisi di materiali policristallini mediante tecniche di diffrazione” by Insubria University Press, we deemed it necessary to widen the scope of our contributions, and to focus on a new, frontier, subject, such as the world of nanomaterials and the most advanced scattering and imaging techniques used for characterizing finite nanosized objects. This book, thus, collects the contributions of many experts in the field and is specifically targeted to the new generation of crystallographers and material scientists dealing with nanocrystalline and defective materials. Both the novice and the experienced scientists will likely find new and relevant scientific aspects, as well as a large up-to-date bibliographic section. Publication of this book on the occasion of the joint AIC-PSI-SSCr International School held in Villigen (CH) in May 2010, was also possible through the volunteering of all the authors, as well as by the generous funding of scientific and didactic projects supported by the Insubria International Summer School, Fondazione CARIPLO, International Union for Crystallography, Swiss National Science Foundation and International Centre for Diffraction Data. Antonietta Guagliardi (09.06.1962) is a Staff Research Scientist at the Istituto di Cristallografia of the Italian National Research Council (CNR) and Professor of Analytical and Structural Methods for Crystalline Matter at the Università dell’Insubria in Como, Italy. She is a member of the European Powder Diffraction Conference Steering Committee, of the Italian Crystallographic Society and Coordinator of the National Commission for Teaching Crystallography. Norberto Masciocchi (30.09.1959) is Professor of Inorganic Chemistry at the Università dell’Insubria in Como, Italy. He is a member of the International Center for Diffraction Data, of the Steering Committee of the XXII IUCr Congress (Madrid 2011), of the Italian Crystallographic Society Board and Editor of the Powder Diffraction Journal. Beyond their scientific interests on diffraction methods for the characterization of polycrystalline matter, on the structural properties of inorganic and metallorganic functional materials, and, more recently, on nanocrystalline materials, they have organized a number of International Schools in the field
Enclosing the functional properties of pyrazolato-based coordination polymers within a structural frame: the role of laboratory X-ray powder diffraction
No full textAb initio X-ray powder diffraction structural analyses from laboratory data have been widely employed in the characterization of coordination polymers not affording single crystals of suitable quality to undergo conventional structural determinations. This is particularly true for coordination polymers built upon strong ligand-to-metal bonds, as those formed by anionic, nitrogen-based heterocycles - pyrazolates, imidazolates, pyrimidinolates and more complex moieties derived therefrom. More than one hundred species belonging to this class have been structurally characterized in the last three decades, affording key, otherwise inaccessible stereochemical and supramolecolar features. This contribution summarizes our most recent experience in the XRPD structural characterization of pyrazolato-based coordination polymers, devoting a special consideration to the methodologies and tricks which allowed us to juxtapose the structural description of these materials to their physico-chemical and, above all, functional properties
Third Euchem Conference on "Nitrogen ligands in organometallic chemistry and homogeneous catalysis", Camerino, Italy, September 2004. Classical organometallic chemistry and beyond
No full textReversibly changing a painkiller structure: A hot topic for a cold case-Ibuprofen lysine salt
No full textIbuprofen lysine salt can undergo a fully reversible, thermally induced phase transition into a different enantiotropically related polymorphic form. The structures of both the high and low temperature phases were solved using state-of-the-art X-ray powder diffraction methods, showing many similarities both in the molecular conformation and in the crystal packing. The full structural analysis and comparison of the two crystal structures allowed to understand the mechanism of the phase transition and explain its reversible nature in what appears to be a rare case of isosymmetric temperature-driven phase transformation of an organic solid
Crystallography for Health and Biosciences
No full textCrystallography is a mature science. Nevertheless, there are fields in which, traditionally, structural and analytical methods different from scattering techniques are more widely used, typically leaving crystallographic methods in the hands of expert scientists, and hampering, in a few cases, the fruitful exchange of scientific knowledge between material scientists, biochemists, biologists and the pharma/biotech industrial world.
To the goal of helping a new generation of young scientists from neighboring disciplines and fields, only occasionally associated with crystallography, we deemed it necessary to organize an International Summer School, in which renowned experts in the field of Crystallography for Health and Biosciences delivered lessons and tutorials, during a full intense week of lectures, discussions and mutual exchanges of opinions.
Accordingly, this book collects the contributions of the Speakers and is organized in four main sections: Part A, in which the basics of the radiation-matter interaction and of the crystallographic techniques are reviewed. Part B, specifically devoted to small-molecule crystallography, with particular emphasis on organic materials (crystal chemistry of drugs and polymorphism). Part C, in which crystallography of nanomaterials and related experimental and computational aspects are presented. Finally, Part D is dedicated to macromolecular systems of biological origin.
Needless to say, the different aspects discussed in this text find a suitable harmony in the mutual contamination of theoretical and experimental techniques, as well as in their underlying and unifying concepts
Fundamentals of Powder Diffraction
No full textIn this contribution we provide the theoretical and experimental basis of powder diffraction methods, which, in the last decades, have been widely used for qualitative and quantitative phase analyses, materials characterization and lately, for structural analyses of polycrystalline species and in situ and real time characterization of chemical reactions and phase transformations
Structural Analysis by Powder Diffraction Methods
No full textHere we provide some basic information about the importance, the procedure and the accuracy of structural powder diffraction methods, with particular emphasis on small molecules crystallography, drug development and polymorphic characterization
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