Source: Acta Crystallographica Section B: Structural Crystallography and Crystal Chemistry 34(11) 3256 (1978)
Because it was determined by Raman spectroscopy. We had 1,4-dichloro- and 1,4-dibromonaphthalene structures. It has the 1,4-dichloronaphthalene structure with broadening, indicating that the bromines and chlorines are randomly arranged.—James Bellows
Source: PDB:3TMI Image generated with PyMol
Until my current job I had worked primarily in cancer drug discovery and knew virtually nothing about the innate immune system. This amazing first-line defense to infection includes the RNA detector RIG-I which grabs onto the invader's double helix. —Kerry Fowler
Source: Dalton Trans., 2014, 43, 95-102
Enatiopurity in both research and industry is extremely important due to the potential adverse effects of enantiomers. Promising drugs like Thalomid have been completely reevaluated based on the adverse effects of the drug’s enantiomer illustrating the importance of ensuring enatiopurity in the synthesis of compounds. Using crystallization, Louis Pasteur was the first scientist to separate the enantiomers of tartaric acid by physically sorting the different crystals into D and L tartaric acid. Louis Pasteur's work helped to identify that the different crystals originated from the molecular asymmetry of the molecule, helping to discover the basis of chemical chirality.—Robert Dyer
Gold face-centered cubic
Source: 1. Goswami, A. M.; Ghosh, S., Biological Synthesis of Colloidal Gold Nanoprisms Using Penicillium citrinum MTCC9999. Journal of Biomaterials and Nanobiotechnology 2013, 4, (2A), 20-27.
Nano-gold is an important model particle to study the – yet very poorly understood – uptake mechanisms of nanoparticles in plants. The unique, distinct and beautiful electron diffraction pattern of gold facilitates identification of the nanoparticles without doubt by means of a conventional electron microscope in the selected area electron diffraction mode. —Fabienne Schwab
Source: Source of photo: Monsanto Research Corp., Mound Laboratory, Miamisburg, OH. (A now closed and environmentally restored DOE laboratory).
Why this is my favorite X-ray crystal structure: The beautiful, strikingly unique structure of B-rhombohedral boron has successfully withstood numerous challenges of its correctness and has for a half century experienced nearly constant investigations of its structurally implied material characteristics. Arguably the most important of the several known phases of elemental boron, this form has been found to be experimentally stable from absolute zero to its melting point. Detailed consideration of the 5-foldness of its numerous discrete and merged 12-atom regular icosahedral motifs and their extended 84-atom truncated icosahedral arrays has forced a significant modification of chemical bonding theory in attempts to explain the low density, high strength, high melting, semiconducting and other notable properties of this low atomic number element. Even the observed partial occupancy of one of its 6-fold Wyckoff sets of atoms within the structure appears to be correct and to imply intriguing electronic possibilities. As one affected colleague has remarked: "You never fully recover from a bite of the boron bug." This structure illustrates some of the allure.—Don Bruce Sullenger
The synthesis is amazing and I am surprised that this compound can even be
Source: Image by Micha L. Rieser
Looking at the photo it’s obvious that their beauty and geometric symmetry are the main reasons my favorite crystals are those formed by bismuth. However, other metals also form beautiful crystals with interesting symmetry. But bismuth may be obtained cheaply and is comparatively safe to work with and handle. A teach may divide a class into several groups and have each group grow bismuth crystals, but have each group grow their crystals with one condition (example, cooling rate) different from the other groups. The images of the crystals grown by each group could be viewed and their digital images captured by a smart phone. Then an app on the smart phone could measure the length and width of the top of each hopper-like crystal, calculate the area of each, and determine the mean area for the crystals by each group and the standard deviation in the mean area for the crystals of each group. Comparing the results of the various groups would lead to a class discussion of statistics and of the possible effects on crystal size of each of the varying conditions. These same experiments would be of great interest to hobbyists wanting to grow bismuth crystals for insertion into items of jewelry.—Robert D. Blackledge
Zeolite MFI revolutionized the chemical process industry as a catalyst and adsorbent and continues to surprise with new and emerging applications and structural variations. It is also prototypical of a series of templated zeolites which continue to find new applications in catalysis and separations. At the time of its discovery, it was also one of the most complex inorganic structures. Moreover, it included an organic cation in the pores making it a prototype of self assembled nanostructure. —Michael Tsapatsis