100 Years of X-ray Crystallography

CsCl

Source: wikipedia

Why?

Its crystal structure forms a major structural type where each caesium ion is coordinated by 8 chlorine ions. Caesium chloride crystals are thermally stable, but easily dissolve in water and concentrated hydrochloric acid, and therefore gradually disintegrate in the ambient conditions due to moisture. Caesium chloride is widely used in isopycnic centrifugation for separating various types of DNA. It is a reagent in analytical chemistry, where it is used to identify ions by the color and morphology of the precipitate. When enriched in radioisotopes, such as 137CsCl or 131CsCl, caesium chloride is used in nuclear medicine applications such as treatment of cancer and diagnosis of myocardial n mineralogy and crystallography, a crystal structure is a unique arrangement of atoms or molecules in a crystalline liquid or solid.[1] A crystal structure describes a highly ordered structure, occurring due to the intrinsic nature of molecules to form symmetric patterns.—v k reddy maddireddy

Human Apolipoprotein A-I

Source: RCSB Protein Databank
(http://www.rcsb.org/pdb/images/1av1_bio_r_500.jpg)

Why?

Human Apolipoprotein A-I has my favourite structure due to its unique shape: it has a Möbius-like shape. Of course, it is not an actual Möbius entity, but it looks quite interesting. In addition, Apolipoprotein A-I has an important function in the homeostasis of the human body. The protein promotes removal of cholesterol from the body by excreting it through the liver. In conclusion, the protein is interesting due to its unique shape (in comparison to many transmembrane proteins which all sort of look similar one way or the other) and due to its significance in promoting health in humans. Thank you! :)—Mitchel Ruigrok

Polyethylene
Single Crystals

Source: Philosophical Magazine Volume 2, Issue 21, 1957

Why?

XRD shows that the chains this image are oriented upright, yet he shadows of these crystals showed they are thin, much thinner than the length of the polymers that make them. The only possible conclusion: the chain are folded back and forth and are not extended like "spaghetti in a box". A revolutionary thought back in 1957 that completely changed our understanding of polymer crystallization.—John Spevacek

Hexagonal Rossete (flower-like)

Source: JACS

Why?

I am a chemist M.Sc student and once I read an article about a special nano Magnesium compund with a hexagonal Rosette crystal structure that was so beautiful. but the most important thing about it is was the ability to atract rare earth elements from waste water. so it was pretty + it had an important recycling roll—Hila Hakak

Diamond cubic

Source: wikipedia

Why?

Most beautiful and useful structure- semiconductors/ high strength materials/jewelery – could you ask for more? And there are ywo interpenetrating FCCs
inside..—Olga Shalev

Perovskite – PZT

Source: Structure generated by Jade2010 from
Materials Data, Inc. using ICDD ref 04-002-9085 (LPF 383176)

Why?

The perovskite structure of lead zirconate titanate, (Pb[Zr(x)Ti(1-x)]O3), known as PZT, is my favorite crystal structure.  Developed around 1952 at the Tokyo Institute of Technology, it is one of the world’s most widely used piezoelectric ceramic materials and touches our lives in the form of ultrasound transducers, sensors and actuators, and capacitors on a daily basis.  As the subject of interest for a plethora of research in our laboratory, PZT holds a special place in the hearts and minds of the faculty, staff and students of the Materials Research Institute at The Pennsylvania State University. —Nichole Wonderling

beta2 adrenegic receptor in complex with Gs (3sn6)

Source: http://www.pdb.org/ (pymol rendered)

Why?

I've been working on GPCR structure and function for the past 10 years. The advances made the past years (including the nobel prize) has motivated me even more to study how these membrane receptors function.—Minos Matsoukas

1,4-alpha-glucan branching enzyme.

Source: Wikipedia

Why?

The branching enzyme has an important role in the determination of the structure of starch in plants and of glycogen in animals and bacteria.—Saaid Ali Mohamed

bis(octaethylporphyrin)zirconium (IV)

Source: ACS Journal of Inorganic Chemistry

Why?

I am currently a high school student intent on pursuing a career in organometallics. One of the main reasons why I love this field is the limitless amount of possibilities – from complex clusters to novel catalysts, there are seemingly no bounds on the structures of the product. In this regard, bis(octaethylporphyrin)zirconium(IV) is exemplary of why I find this subject so intriguing, especially how its outlandish crystal structure can be synthesized
in a relatively standard manner.—David Wang

Buckminsterfullerene or buckyball

Source: crystallography365

Why?

The shape is well learned and remembered at a young age. Reminds me of a soccer ball.  —Gobishankar Sooriyakumar

Ice

Source: Google images

Why?

I like the hydrogen bonding, as well as, crystallized water is one of the few things that expands when it freezes. Not to mention, water is a source to life. —Jonathan Prince

1RWT

Why?

(1) 42 chlorophylls pack inside a functional trimer! (2) It is a crystal of (the most abundant) membrane protein! (3) Icosahedron!—Yang-Ting Chen

DNA

Source: Wikipedia

Why?

It is the foundation of life. The better we understand it, the better the quality of life will be for many generations to come.—Michael Morgan

K2[Re2Cl8]·2H2O

Source: Wikipedia

Why?

First verification of a quadruple bond—Bill Sanborn

salt crystals

Source: my own camera

Why?

The salt crystal just shows me how great is the creation of the Lord… :D—Rafael Miguel M. Dela Cruz

DNA double helix

Source:
http://www.nature.com/scitable/topicpage/discovery-of-dna-structure-and-function-watson-397

Why?

The structure of DNA is not only beautiful to look at, but our ability to understand DNA has been instrumental in everything from medical breakthroughs, to solving crimes, to understanding what we are as lifeforms, and how we relate to other life around us. Without our understanding of the structure of the double helix, many of us wouldn't have jobs today!—Eris Walsh

Icosahedral Quasicrystals

Source: ammin.geoscienceworld.org

Why?

Quasicrystals like these have long-range order but not translational symmetry, and in that way — to me — each tiny grain of every crystal reflects the entire universe. By showing that chance, coincidence, and beauty can all culminate between chemistry, optics, and even theoretical physics in one single crystal, I'm reminded of the oneness scientific pursuits give us in life. That's why we're here! Between a tiny crystal and the entire universe, the same principles are naked to our curious minds… that's why icosahedral quasicrystals are my favorite X-ray crystal structure.—Bradley D. Proffit

K3MoO3F3

Source: Personal

Why?

This is my favorite crystal structure because the material family had been studied for almost a century, however the structure (cubic perovskite) was not consistent with the properties (ferroelectric response) and I had the opportunity to solve the structure for my PhD. We found that it had a massive unit cell and it added to a growing number of non-cooperative octahedral tilted perovskites. In a nut shell it is my favorite because I feel like I got to see a glimpse into K3MoO3F3 before anyone else.—Allyson Fry

Lonsdaleite

Source: webmineral.com

Why?

Lonsdaleite, also called hexagonal diamond in reference to the crystal structure, is an allotrope of carbon with a hexagonal lattice. In nature, it forms when meteorites containing graphite strike the Earth. The great heat and stress of the impact transforms the graphite into diamond, but retains graphite's hexagonal crystal lattice. Lonsdaleite was first identified in 1967 from the Canyon Diablo meteorite, where it occurs as microscopic crystals associated with diamond. Its hardness is theoretically superior to that of cubic diamond.

Sometimes I said to my students that: It is stronger than the strongest.—Juan Carlos Munoz

Sodium dodecyl
sulfate

Source: Wikipedia

Why?

This unsung and highly versatile molecule improves human life in countless ways.—Craig Luther

polyethylene oxide single

Source: Macromolecules, 2008, 41 (1), pp
149–155

Why?

What can be cooler than a squared crystal?—Ziyin Huang

NaCl Tipe

Source: Wikipedia

Why?

Is the most characteristics crystal of nature, and it's
beautifull.—Favio

Nd2Fe14B

Source: iopscience

Why?

The P42/mmm space group contains opposing layers of simple ordered sheets of neodynium, iron, and boron, and chaotic hexagonal iron nets. The contrast between these two layers (simple vs chaotic) makes the crystal structure very beautiful in my eyes. Additionally, it is very fun to find the order within the
chaotic hexagonal iron nets. It takes a while to find all of the order in what. seems like utter randomness.—Dr. Brandon J. Burnett

1hnx

Source: homebrew pymol image

Why?

Unusual binding mode of the antibiotic pactamycin – and one of the earliest published structures of a major ribosome subunit. Have a look at the intramolecular stacking!—Szilveszter Juhos

Calcite

Why?

Amazing biomineral—Athanasios Godelitsas

Rh-norbonane complex (CCDC CSD

Why?

Its a Rhodium-sigma complex! An alkane bound to a metal as a ligand, very hard to get crystallographically. Alkane complexes are proposed intermediates in C-H activation and C-H bond reductive elimination. —Kyle Grice

Ethylenediaminium(2+) fumarate(2-)

Source: Own undergraduate research

Why?

It is one of the first structures solved in my undergraduate research.—Georgiy Akopov

isotactic polypropylene

Source: Nuovo Cimento, 1960

Why?

This structure — solved by Paolo Corradini, working in Giulio Natta's laboratory in the 1950's — provided a compelling proof of the possibility of "breaking Nature's monopoly" in the synthesis of stereoregular polymers. The polymer chains adopt a helical conformation, in a striking analogy with DNA and alpha-helical proteins (whose structures had been worked out shortly before by Watson&Crick and by Pauling&Corey).—Guido Raos

PDB ID 1PRC, the photosynthetic reaction center from Rhodopseudomonas viridian

Source: DOI: 10.1006/jmbi.1994.0097

Why?

The first atomic resolution structure of an integral membrane protein was a tour de force of protein purification, crystallization and phasing. The resultant structure taught us a huge amount that was generalizable to other integral membrane proteins and about the interaction of proteins with the lipid bilayer. This particular PDB deposition represents the refined coordinates to 2.3 Angstroms resolution, and thus the authors were able to locate associated lipids and solvent molecules in addition to determining the positions of the cofactors and protein side chains.—Diana Tomchick

Copper(I)
tetrakis(4-cyanophenyl)methane tetrafluoroborate

Source: JACS 1989, 111, 5962-5964 (pic on p5963)

Why?

The first example of deliberate design of a crystalline coordination polymeric material. The components were chosen for specific geometric preferences, and the resulting structure showed one of the two predicted possible coordination networks.—David Cordes

luciferase

Source: RCSB Protein Data Bank, rcsb.org

Why?

I like looking at how fireflies light up at the molecular level.—Christine Zardecki

Aromatic ring – benzene, naphthalene, heterocyclic compounds,

Source:
https://pubchem.ncbi.nlm.nih.gov/vw3d/vw3d.cgi?cmd=crtvw&reqid=4154098881471962712

Why?

Aromaticity problem, actual structure present in the different organic molecules confirmed, presence, occurrence, state, nature, form, size of the molecule can be predicted and established as a fingerprint for the compound with aromatic ring.   —Prabhakar Ramabhilash Sharma

6-bromoindigo

Source: personal

Why?

It has historical significance as part of Tyrian Purple dye, but unlike indigo or 6,6-dibromoindigo, it wasn't solved until recently. The crystals were very difficult to obtain and there was twinning in the crystal structure.—Olga Lavinda

Cubane

Source: http://web.ornl.gov/sci/ortep/cubane/cubane.html

Why?

When I was learning crystallography at Stanford in the 70's, cubane was the model compound used in the ORTEP manual.  And some of the compounds I worked on had pseudo-cubane structures.—Michael A. Bobrik

Sodium Rubidium Tartrate

Why?

As an undergraduate and budding organic chemist at the time, I was blown away by Bijvoet's determination of absolute configuration for the first time.
—Joe Atkinson

Polonium

Source:
http://en.wikipedia.org/wiki/File:Alpha_po_lattice.jpg

Why?

Because it can't get any simpler than this! Polonium is the only crystal with simple cubic lattice and one-atom basis. How on earth could this be a thing?—Maciej Malinowski

[Co8C(CO)18]2-, benzyltrimethylammonium salt

Why?

Because it is an organic chemist's worst nightmare. Carbon with EIGHT bonds!—Jason Smee

Au102(pMBA)44

Source: Science, 2007, vol318, 430

Why?

The structure of Au102(pMBA)44 is the first large thiolate-protected gold cluster to be solved.  The structure of this molecule reveal an important common staple motif which are also found in many other gold nanoclusters. With none of the fragments being innately enantiomeric, the assembly of the gold atoms and the ligands forms two enantiomers. —Andrea Wong

Transfer RNA

Source:
http://www.rcsb.org/pdb/101/motm.do?momID=15

Why?

It was one of the hardest work to reveal the structure of the transfer RNA. It is one of the greatest breakthrough in biochemistry. Thanks for several great scientists and strong efforts it is revealed now.—Levente Pap

Ferrocene

Source: My own photograph

Why?

Haiku to ferrocene

Twenty-one atoms

Open a new world for science

Iron in the heart—Stephanie Hurst

molybdenyl acetyacetonate

Source: CAS # 17524-65-9

Why?

This was the first molecule whose crystal structure I determined. It was interesting because the molecule was assymetric and had four molecules in the unit cell. The central molybdenyl group has the oxygen atoms in a cis configuration rather than trans as might be anticipated.—Dr. William B. Wise

DNA

Source: Rosalind Franklin in C&EN

Why?

With very little data from a purloined photo of Rosalind Franklin, Watson and Crick solved the basic structure of DNA and changed the way we think of 'life' forever. The breaking and forming of hydrogen bonds is how we procreate- and it is just chemistry which has taken billions of years to get to life today.—Jane F Griffin

sucrose

Source: wikipedia

Why?

It's sweet!! — Sergio Gonzalez

snowflake

Source: physicsworld.com

Why?

The sheer beauty and the reverting back to my childhood every time I think of the old statement that "no two snowflakes are alike" this again opens my mind to the endless possibilities of the world we live on. naive perhaps but enjoyable.—Karl B. Hensel

Ferrocene

Source:
http://syntekglobalxtremefueltreatment1.wordpress.com/2012/12/23/xtreme-fuel-treatment-effects-of-ferrocene-as-a-gasoline-additive/xftferrocenemolecule/

Why?

The fantastic structure has a beautiful symmetry, which has been used to teach group theory in my class. And I love the process how people eventually solve the puzzle about the structure. X-ray crystallography rocks!—Lei Yang

Celecoxib cocrystals with syn amides

Why?

Trimorphic cocrystals of Celecoxib with Valerolactam reported in this study. Even ring size lactam coformer attributed Dimer-Catemer, Dimer-Dimer Synthons where as odd ones resulted hetero synthon. Synthons between the sulphonamide and lactams are explained as even–odd ring size. The present study on sulfonamide−lactams provides a starting point for synthon based crystal engineering of sulfonamide drugs. Single crystal X-ray structures of celecoxib cocrystals are reported for the first time with GRAS lactams—Geetha Bolla

Ice

Source: wikipedia

Why?

Ice is cluster of water which is life. It is made off of very simple molecule like water but so interesting. Naturally occurring. —Sharmita Biswas

Manganese(II), bis(1,4,7,10-tetraoxacyclododecane)manganese(II) tribromide

Why?

That crystal structure (and its related chemistry) was the basis for my earning a doctorate in chemistry.—Michael Hampton

Tryptophan synthase

Source: J. Biol. Chem. 263, 17857-17871 (1988).

Why?

The structure in 1988 was the first structure of multienzyme complex and the first structure that showed a tunnel. —Edith Miles

Triiron dodecacarbonyl

Source: Wikipedia

Why?

Triiron dodecacarbonyl has a simple formula but a complex structure. There was much debate over the structure until X-ray crystallography put it to rest.—Brad Steinhoff