SCANZ Crystals: o&LeSafte-M Pan Perennial objects of desire Essential for determining how atoms arrange themselves and why materials have the properties they do! Numerous applications in materials science,nano-technology, biology/medicine/pharmaceuticals.. Pyrite or "fools gold"Grenoble Natural History Museum A presentation initially prepared by the French Crystallographic Association for the exhibition"Journey into the Crystal"and modified to celebrate the International Year of Crystallography (IYCr)in 2014 6 IYCr2●14 100 ans de Voyage Cristallographie rista b/组Rhonedlpes isere.度 品61AN卡洲伞画总
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Crystals:Objects of beauty and source of riches From the earliest times,humans have been aware of rocks/stones emanating from the centre of the earth of an incredible variety of shapes and sizes.Multifaceted crystals,in particular,inspired wonderment.They were called "stars from the centre of the earth". These "stones"came in a multitude of shapes,sizes and and colours.They sometimes took the form of unusual"angular stones with flat,smooth sides,as if manufactured.Some of these became known as "Crystal"Their fascinating colours,shapes and sizes naturally attracted mysticism:crystals were talismans of supernatural power supposed to offer healing and protection.... The colour,transparency,rarity and stability of certain stones made them precious objects used in jewels and gems.They became symbols of power and wealth. 滑 Crpstal:adefinonta hasevved hthea动0esnteendlonhonsneogglmtowdctendy CakiteMarelln bere rngdnnotkrda IYCr2oi4
"Angular Stones": The Birth of Crystallography During the Renaissance,a discussion began:do crystals stem from the growth of inert matter or are they somehow sculpted?Using his observations of the shape of quartz crystals,Steno,in the 17th Detahethoffuytaktryue century,was one of the first to imagine crystal growth.It was only during the 18th century,however,thatcrystallographers'formed a picture of the internal structure of crystals by focussing on their external geometry. It was the discovery of the"constancy of the angles"between the various faces of a given type of crystal,which first drove scientists to suggest that crystals must be made out of a stack of basic building blocks or bricks.This model allowed them to explain crystal faceting.The works of Steno,Rome de L'lsle and Hauy and numerous other scientists thereby gave rise to the new science of "crystallography" In the 19th century,German and French researchers introduced the concept of symmetry to classify crystals.They used mathematics to formalize their classification theory.Thus,by the beginning of the 20th century,even without being able to "see into"a crystal, crystallographers had developed the notion of atomic order and periodic repetition to understand both the external form of crystals as well as their symmetry. IYCr2●14
Crystals and X-rays:made for each other! the ideal tool for studying crystalline materials Insight into the internal structure of crystals initially grew out of using crystals to understand what X-rays were:insight often comes in unexpected ways! X-rays:In 1895,Rontgen discovered a new type of radiation but was unable to determine its precise nature.In the end,he gave up and called them X-rays.Invisible and able to pass through solid matter,these rays were studied by scientists from Australia,Britain and Germany who used crystals to understand their properties.In 1912,von Laue,Friedrich& Knipping exposed a crystal to X-rays.The experiment,now called diffraction,was initially carried out in order to understand the nature of the radiation;instead,its real importance was to reveal the regular order and symmetry of the crystals themselves.This led to the extraordinary possibility of determining the internal atomic arrangement of all crystals. William Lawrence Bragg and his father,William Henry Bragg,realized that X-rays could be used to understand crystals,to"see"their inner structure and thus developed the new science of X-ray crystallography.WL Bragg is most famous for his law on the diffraction of X-rays by crystals,made tn the pattee hesame symmetry during his first year as a research student in 1912.Bragg's law made it possible to calculate the positions of the atoms within a crystal.The 'diffraction"of X-rays thus changed from the status of being a physical phenomenon to that of a tool for exploring the arrangement of atoms within crystals.This discovery led to an intense period ofresearch.Most of these pioneering scientists received Nobel prizes,including the first Australian,and the youngest ever,Nobel Prize winner,WL Bragg. 入=2d.sim0 Hrase's taw e:ge dansna umHn8e与 2.ws an ncnd m Lawrence Bragg Pri Nob oll Cavendah Labotatory IYCr2●14
Alice and Joseph in crystal-land Josegh Fourier The structure of crystals could not,at the time,be seen directly with a microscope,but had to rely on diffraction.The geometry of the locations of the different diffracted beams/spots allow the structure to be represented in a virtual space which is called "reciprocal space". Using mathematics to visualise crystals Travelling into"reciprocal space A precise mathematical relationship,the "Fourier The direct observation of "reciprocal space"via Transform",exists between the "reciprocal space" diffraction enabled crystallographers to see the observed by diffraction and the real structure of the symmetry of a crystal,the dimensions of its crystal in "direct space". building block or"unit cell"and finally to"see"the atoms themselves:the diffraction pattern is a In order to 'understand'this relationship,think of finger print which identifies each crystal. Alice (in Wonderland),who has a direct view of the world of the crystal and its atoms,and that of To understand more... Joseph (Fourier),who can only see those produced by the diffraction spots! Diffraction may appear complicated because it provides an inverse image,but this is nothing more than a superposition of sine waves,discovered by Joseph Fourier when he was the state representative "prefet de Grenoble"under Napoleon the First. *61:0065006806. Gr-jomnal J IYCr2014
Crystallography and Crystal Chemistry Crystals are essential to modern society,their study using X-rays (radio-crystallography)gave birth to crystal chemistry,at the beginning of 20th century. 运打 llG-bem Crystal chemistry's objective is to explain the relationship between the properties,the chemical composition and the arrangement of atoms in crystals. The crystallographic approach Applications for crystallography today exist not only The crystallographic approach to understanding in materials science,but also in the synthesis and atomic arrangement represented a revolution for structure determination of new molecular materials Strxture-Property Beltions science.For the first time,we could directly see the incuding the development of new medicines. atomic structure and make-up of materials.This enabled scientists to focus on developing strategies for making materials with new and/or improved physical properties e.g.new generation batteries. new materials for hydrogen storage..etc. in principle if a compound or substance can be crystallised its structure can be determined by X-ray crystallography. G-jouaks IYCr2014
Nano-porous Crystals the zeolites To understand natural crystals,to duplicate them, and then to do better...the art of synthesis! The stone that boils: There are around 50 natural zeolites an amazing crystal and more than 500 artificial zeolites have now been synthesized... In 1756,Cronstedt made an astonishing discovery: while heating a sample of the mineral stilbite,it by using the crystallographic approach scientists became covered in bubbles at around 150C,as if were able to "visualize"the different atomic the stone were boiling.Hence the name given to arrangements and cavities,enabling them this mineral:"zeolite,from the Greek zeo (to boil) to understand and then create new zeolites. and lithos(stone) Zeolites are widely used in industry for water X-rays provide evidence of the nano- damnes-to purification,as catalysts,for the preparation of porous structure of this crystal advanced materials and in nucear reprocessing.They e de are used to extract nitrogen from air to increase In 1930,Taylor and Pauling used X-ray diffraction to oxygen content for both industrial and medical study the first zeolite crystals and revealed that,at purposes.Their biggest use is in the production of an atomic level,these minerals are made up of a laundry detergents.They are also used in medicine,in nano-porous matrix.Stilbite is a sodium calcium agriculture and in the oil industry. aluminium silicate that can hydrate or dehydrate in a reversible manner,according to the temperature. Water is trapped within the cavities of the structure. IYCr2014
Crystals, chirality and Pasteur The concept of chirality is very important in many branches of science.It is responsible for properties such as the direction of rotation of plane polarized light,the taste and smell of chiral compounds and it is fundamental to the chemistry of living organisms. Chiral comes from the Greek word chiro which Our body is made up of basic chiral means hand.When the palms are tumed towards the sun,the left hand cannot be superimposed on structures:amino acids,sugars.. to the right hand. A chiral molecule in one isomer or another will not have the same effect on our bodies.This is the case with many drugs and medicines as well as in The chirality of molecules the perception of tastes and smells. In 1848,Pasteur commented that crystals can have two identical and yet opposing forms,a mirror image of each other.He interpreted it as the existence of two chiral molecules.The chirality of crystals is primarily due to the manner in which the constituent atoms or molecules are arranged. Asymmetric molecules have two chiral forms, generally in nature one of these two forms is dominant. ehenaneemg asparagine s asparagine R 效共 H carvone carvone IYCr2●14
Using crystals to understand living organisms Biological cry以ab At the interface between chemistry and biology: In order to understand the way a living organism functions as well the role of the various proteins involved,scientists have long sought to see their structures.For this,X-ray diffraction has proved to be an extremely powerful technique.It does have one limitation:the proteins must be in a crystalline form. de FUMER "Growing"protein crystals. ...to study them. Proteins are very large biological molecules There exists a very strong relationship between the (macromolecules)and essential for life.They are atomic arrangement (the structure)of a biological made of amino acids.Each protein has a specific macromolecule and its function:the precise 标书th球w间eh意6 function,directly linked to its three-dimensional knowledge acquired about its forms means that a structure,i.e.the manner in which the amino acids hypothesis can be made regarding its role and the are laid out,one against the other in space.Proteins manner in which it carries out its functio do not naturally form crystals,so they have to be Studies relate to both basic research,in order to grown artifically. acquire a precise understanding of the bioogical processes,and applied research, leading to the synthesis of new medicines. Mcromoules (rpmak Cr-kumk IYCr2014
Egyptian cosmetics.. and crystallography！ Objects found in ancient burial sites are often made up of crystallized chemical materials.These crystals are,for those who know how to 'read them',real archives. The first chemical solution synthesis Egyptian make up, invented by Man knowledge from crystals Researchers have shown that these crystals are rare The use of kohl,black eye makeup,is recorded from chlorinated compounds of lead.The synthesis method ancient Egypt.Analysis of cosmetic powders taken (in aqueous media)can be found in Greco-Roman from funerary objects preserved in the Louvre texts.These texts reveal that the artificial white Museum,has identified the major component of precipitates were highly valued for their medicinal these old cosmetics as a crystalline lead ore,galena properties,especally for the eyes.The ancient (PbS)but also.the presence of far rarer crystals... Egyptians were thus the first to use soft chemistry to develop cosmetic products to protect them from eye infections,common in the hot and humid climates along the Nile..the cradle of their civilization. dehe 5355 Reconstituted preparation,by using galena (PbS)litharge (Pbo)gemmed salt (NaCl)and water (H20).then byaddingnatron (Na203)toobtain laurionite (PbOHCl) and phosgenite (Pb2C12C03)LC2RMF-CNRS Le Louvre