100 Years of X-ray Crystallography

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

Metal Organic Frameworks (MOFs)

Source: JACS

Why?

MOF crystals are going to be a host for many gases such as H2, CO2 & CH4. So it will be a environmentally & eco friendly crystals..—S.Senthilkumar

W(PPh3)3(CO)2Cl2

Why?

First crystal structure I ever took in lab class!—Adam Coleman

Iron Superoxide Dismutase

Source: Jane Richardson drew this for Dagmar

Why?

The first structure Dagmar Ringe and I ever solved together, initiating a scientific partnership and friendship that has lasted 34 years.—Greg Petsko

Penicillin

Why?

It was the first large molecule to have it's structure confirmed, which opened the development of other life saving analogs.—John McCarthy

Graphene

Source: Wikipedia

Why?

Graphene certainly changed the way things work with Organic Electronics, which have the potentiality to replace all inorganic electronics and improve quality,durability and performance and most importantly flexibility..—sambasiva bheemireddy

Itraconazole succinic acid cocrystal

Source: JACS

Why?

Crystal structure analysis has been central to the design of pharmaceutical cocrystals in the past decade in the quest for new materials for drug discovery and development. Intermolecular interactions in this pharmaceutical cocrystal are counterintuitive: the strongest base in the drug molecule is not involved in hydrogen bonding or proton transfer – Packing drives the shape of the complex of 2:1 drug:diacid. This knowledge helped to design other materials with new properties, such as improved dissolution for oral delivery. —Orn Almarsson

ferrocene

Why?

It seemed such a unique sandwich structure which incorporated an organic compound and a metal. Beautifully explained bonding by molecular orbital theory.—Daria N. Lissy

no one structure in particular

Why?

As a patent attorney, I often get rejections of patent applications by Examiners based on similarity of compositions in the prior art. Often, the
similarity is replacement of one component in a crystal with one of another component of different ionic radius or charge. I am usually successful in pointing out the strain on a crystal from such replacements such that the seeming similarity should not adversely affect patentability.—Alan Ehrlich

K2[Re2Cl8]

Why?

It was the first structure to show a quadruple bond.—Chris Durr

NDTB-1

Why?

Dr. Thomas Albrecht Schmitt's NDTB-1 (Notre Thorium Borate-1) is one of my favorite crystal structures because it demonstrates a color change occurring between the single crystals. As the anions were exchanged, the colors of the transition metals appeared. These colored crystals remind me of my graduate work performed in his research group. I incorporated first-row transition metals into uranium phosphonate systems.  This resulted in colored crystals that were due to electronic coupling from the 5f-3d electrons.—Andrea Alsobrook Bridges

racemic and enantiopure ribo-aminooxazole

Source:
http://www.nature.com/nchem/journal/v3/n9/pdf/nchem.1108.pdf%3FWT.ec_id%3DNCHEM-201109

Why?

This molecule has been identified as possibly one of the earliest progenitors to RNA on a pre-biotic earth. This simple product, formed by the condensation of HCN and formaldehyde is so important because it easily crystalizes from solutions containing complex mixtures of product, allowing it to accumulate in the environment and "outlast" normal breakdown. This purification and sequestration by crystallization also has another very important feature; it allows the molecule to separate as a single enantiomer. This is a critical feature, as without enatiopure starting material RNA self replication would not be possible. The key question was weather ribo-amino-oxazole preferentially crystalized in its enantiopure or racemate form. Moreover, we needed to know how it would spontaneously nucleate from a very complex reaction mixture to mimic how this may be relevant to a pre-biotic environment. Our study showed that while the pure ribo-amino-oxazole tended to form a racemate crystal (and thereby would allow both enantiomers to accumulate), it prefers the enatiopure crystal from when nucleated from complex reaction mixtures. This study offers a glimpse at RNA could have been formed spontaneously and may offer proof as to why all RNA and DNA exists as a single chirality.—Jason Hein

Insulin

Why?

A beautiful molecule deciphered by a wonderful human being, which still makes the whole difference for an incredible number of people.—Filomena Martins

DNA double helix

Why?

Dawn of modern biology in cell metabolism and genetics, Mother Nature's masterpiece, the DNA structure elucidation research was effectively aided by some phenomenal X-Ray crystallography work by Rosalind Franklin. It was a pity that her work was often overlooked as a result of her untimely passing too young to receive the Nobel Prize. The winners list of the prize should have been Crick, Watson Franklin, & Pauling.  The record stands as Crick, Watson and Wilkins.—Kreisler Lau

U60

Source:

Why?

This is a structure grown during my PhD work. The crystals look like yellow diamonds and have the structure of U60. U60 is an uranium peroxide nanocluster containing sixty identical polyhedra. The structure is isostructural to the C60 buckminster fullerene but is approximately 2.5 nm in size.  I have it with me at all times in an image on my watch.—Ginger Sigmon

SGPB

Source: ACA Newsletter 2009

Why?

SGPB is a serine protease from a bacterium that has a fold similar to that of mammalian trypsin. It was the first protein structure to be determined in Canada in 1974. It has played an important role in determining the sequence to reactivity algorithm of Michael Laskowski Jr.—Michael James

Time-resolved crystallography of myoglobin ligand dissociation

Source: J Struct Biol, 2004, 147, 235

Why?

This was the highlight of my undergraduate course in protein structure and dynamics. The animation is a time-resolved combination of x-ray crystal structures of myoglobin's haem binding site. From the electron density maps you can see not only the amino acid residues of the active site, but also the movement of the dissociating ligand and the residues of the active site. The visualisation of protein fluctuation on such a scale is truly beautiful!—Charles Evans

Ligand binding structures of myoglobin

Source: Nature 404, 205-208 (9 March 2000)

Why?

A highlight of my undergraduate course in protein structure and dynamics, this series of crystal structures have been animated to show the conformational changes around the haem site of myoglobin. You can see the movement of the dissociated CO around the site, and the movement of individual amino acid residues as the local environment changes. It's truly beautiful to watch a protein's dynamics in such close detail!—Charles Evans

RNA Polymerase II

Source: NIH NIGMS Image Library

Why?

This enzyme is key to the generation of mRNA from the DNA in our cells. The mRNA it generates is defines the amino acid sequence of the proteins in our cells. This enzyme is one of the many key building blocks of life.—Richard Barfoot

Emoglobin

Why?

It is the best achievement of the 20th century—Alberto Schiraldi