 The research that I've been working on for many years is studying the chemistry of molecules called porphyrins. A porphyrin is a donut shaped molecule. So it's a molecule in a ring shape. The ring contains 20 carbons and four nitrogens and they're held together with covalent bonds. It's pretty much the same color as blood and that's because porphyrins are the molecules that give blood their red color. What lives in that hole in the middle is iron. It's a single iron atom so although iron is a metal in this example it's not participating in metallic bonding which occurs when you've got a whole ensemble of metal atoms. It's a single metal atom that actually forms covalent bonds to the four nitrogen atoms. It's it's the part of him that you know carries oxygen and in the gap above the iron atom that's where it couldn't bonds to oxygen. The thing that most people can kind of grab on to is that you've got iron and oxygen and water and that usually gives rust but how come my blood doesn't rust and it's because iron and oxygen in water just iron and air forms really strong bonds with oxygen and so it kind of goes energetically all the way down hill to rust and it's a one-way chemical reaction but the really important thing about hemoglobin the iron in hemoglobin sitting in the middle of the porphyrin is that the porphyrin and the protein that wraps around it changes the interaction between iron and oxygen so iron forms a much weaker bond with oxygen so just strong enough to hang on while it transports around your body but at the same time weak enough that when it gets to your tissues it can fall off. That doughnut shape it's actually the bright red color of blood comes from that doughnut shape and if you take that same doughnut shape and just modify it a little bit change a little bit of the bonding between some of the carbon atoms and take out iron and put in magnesium instead of being red it's green and that's the pigment and chlorophyll so then it does something completely different it uses the green color to absorb sunlight energy and what it does is it absorbs the energy and then it's the first step in a whole chain that passes that energy along to drive photosynthesis because both of those molecules are sort of doughnut shaped and brightly colored so if we can use their capability to either change the chemistry of the metal iron that sits in the middle like we do in hemoglobin with iron or use the fact that they're brightly colored which means they're really good at absorbing light energy if we can harness those properties then we can use them for example in light harvesting systems to make a new kind of you know photochemical cell their doughnut shaped so that you can lie them on surfaces where you can stack them up you know in hemoglobin that the porphyrin tucks inside a little pocket in a protein but we can design other little pockets that the porphyrin will tuck inside so I don't actually study stuff to do with blood I study the way in which that molecule has special properties and as an example there's a very closely related molecule if we cut it in half and put a boron atom then we make something that fluoresces bright green and so we figured out a way to attach that directly to a sugar so we can make sugars light up we can make sugars glow the other thing about those porphyrin molecules again the red ones is we know they're brightly colored which means they're really good at absorbing light energy so we've also had a project where we put them on surfaces and then we use them to absorb some light energy and transmit that energy to the surface and then in the presence of a gas molecule like say a contaminant that you might want to measure in the air like nitrogen oxides if there's a gas molecule in the air that interacts with the porphyrin on the surface it will change the interaction with the surface in a way that we can measure so we can use that same molecule in a gas sensing system