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Asked by anon-256741 to Eleanor on 9 Jun 2020.
Question: What kind of crystals did you grow
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Eleanor Barber answered on 9 Jun 2020:
Hi Ben! I think you asked this is the chat but I’ll answer here as well so that everyone can see.
The crystals I grow are all inorganic salts – for example potassium chloride, aluminium chloride, cesium chloride and sodium bromide. They are all white powders when we buy them, but the crystals can be different shapes and quite beautiful. I choose these chemicals because we know they will work with the technique I am using.
Some interesting crystals I have grown are sodium acetate – this is the chemical found in reusable handwarmers. If the samples are crystallised in the ‘normal’ way, white crystals form and heat is produced (like in a handwarmer). But using the laser technique we get a different kind of crystal. Things like this could be useful for producing pharmaceutical drugs, because different crystal forms react differently with the human body – so we need to be able to control which one we grow!
Comments
Ronan commented on :
I used to grow single crystals of compounds never made before. Single crystals mean X-ray diffraction can tell you for certain what the molecular structure is. The one I am most proud of was single crystals of a surprising Pd compound in which the Pd atom is in a rare triangular geometry, and it will spontanteously decompose from orange crystals to black gunk if it was not kept in an atmosphere of carbon monoxide.
David commented on :
Hi Ben,
Although I am now into computational chemistry, my master’s degree was in inorganic chemistry. I had the opportunity to work in a really large and diverse research group which means I was able to try different things. I worked with some metal-organic-frameworks, metal-halogen-chains and single-molecule magnets. For each of these 3 research areas, I need the crystals so I can accurately determine the structure of the final compounds I have made as well as have a deeper understanding of the behaviour/properties of the compounds with great insight when I measure them. The above-mentioned classes of compounds require me to use organic compounds (which serve as ligands) to react with various transition metal salts or with the simple salts of the lanthanide ions to form complexes that can either the classed as metal-organic-framework, metal-halogens-chains and single-molecule magnets.
First, I have to prepare the organic compounds depending on what I want the final compound to look like and then try to grow their crystals. Sometime, it could really be challenging to grow these crystals, but the good news is that the more challenging it is, the better understanding you have because that would mean that you need to try many different methods and conditions from as simple as slow evaporation to as complex as using electrolysis. Having the exact structure of the organic ligands allows you the flexibility to choose your transition metal salt that will give you a unique structural design. I have grown crystals that come in different shapes, sizes and colours and they really looked so beautiful. I could remember a crystal I made from a compound containing palladium, lanthanides like dysprosium and acetic acid as the ligand. It was so beautiful, shiny and looks pretty much like a gold-plated crystal that I wanted to just keep it in my cabin forever.
For many inorganic chemists, getting the crystal structure of your compound sounds more like winning a competition where you will be given a national award. The joy of watching those crystals grow from tiny bits to in some case really large crystals could really be immeasurable, especially when the crystals are for complex systems and turns out to be what you are targeting. However, not all crystals will give you that joy, sometimes you can get a really pretty crystal and it will simply be a heartbreaker because, despite its beauty, it might not be what you are hoping to get. However, that might not be completely bad news because sometime that might just be one of those unexpected compounds that will change the world and get you to be famous.
Jane commented on :
In my first job after leaving university I spent 1 year growing a single bright blue Copper Sulphate crystal. It weighs 840 g and is still my pride and joy. I wish I cold include a photograph!