Osmium, a group 8 d-block transition metal discovered in 1803 by the English chemist Smithson Tennant, is the rarest of the stable elements. Concentrations in the Earth’s crust are around 50 parts per trillion. The metal is found in nature uncombinrd or alloyed with its neighbour, iridium, in the alloys iridosmine or osmiridium. Around 500Kg

Vanadium (V, Element 23) Vanadium, a group 5 transition metal, discovered in 1801 by Andres Manuel del Rio, occurs naturally as a component of vanadinite (Pb5(VO4)3Cl), one of the main industrial ores used as a source of the metal. Over 60 ores are known, with 70-80 thousand tonnes of ore mined globally each year, producing

Figure: 1 The idea of using transition metal chemistry in a cellular setting might at first seem counterintuitive- biological conditions are challenging with respect to stability, efficiency and catalyst (not to mention patient) poisoning. Having said that many important intracellular processes are modulated by transition metals complexed in metalloproteins, with functions including storage and transport